Patent Publication Number: US-2023150079-A1

Title: Systems, methods and apparatus for guided tools

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
     This application claims the benefit of priority under 35 U.S.C. § 119 to U.S. Provisional Patent Application No. 62/161,179, filed May 13, 2015, which is hereby incorporated in reference herein in its entirety. 
    
    
     BACKGROUND 
     Visual guides that are drawn on material may be difficult for a user to follow manually. Further, it may be difficult to determine a position of a tool on the material. 
     SUMMARY 
     Apparatuses, systems and methods of the present disclosure facilitate guiding a tool. In some embodiments, the system includes a rig or frame with a stage that may be positioned on the surface of a piece of material such as wood. The tool can be electrically or mechanically coupled to the frame, and the frame together with the tool can be passed over the material. The system can include sensors, cameras or positioning logic to determine the tool&#39;s position on the material and accurately move (or provide instructions for a user to move) the frame, stage, or tool to a desired coordinate on the material. 
     In some embodiments, the surface of the material can be marked with location markers that facilitate detecting a location of the tool relative to the surface of the material. The marker can be designed or configured to facilitate easy, fast, and reliable detection by a sensor of the tool. In some embodiments, the marker may include a binary image or be constructed in a manner that can be easily converted to a binary image. For example, the marker may include a fiducial marker that can be detected with minimal computation power, such as a black-and-white image that may represent dominoes. 
     In some embodiments, the present disclosure is directed to a system, method or apparatus of directing or extracting dust that may be generated while performing a task on a surface of a material. For example, while a cutting tool is cutting a material such as wood, saw dust may be produced which may make it difficult for the tool to detect markers that may be placed on the surface of the material. The tool of the present disclosure includes a cavity in which the dust generated by cutting the material can be directed. For example, the cavity may include a void in tool frame, and a fan of the tool may direct the dust towards the cavity. Further, a vacuum may be coupled to the tool such that the dust can be extracted via the channel. 
     In some embodiments, the present disclosure is directed to a system, method or apparatus for determining the position of a tool relative to a work surface. The system, method or apparatus can determine changes in the force exerted by the tip of the tool (e.g., a cutting bit) in order to determine when the tip of the cutting tool is touching or pressing against the surface of the material. For example, the tip of the tool may be in a first position that is not touching the work surface. The tip may gradually move to a second position that touches the surface of the material. When the tip of the tool moves to the second position, the system, method or apparatus can determine a change in the force, which may indicate that the tool tip is touching the surface of the material. For example, the force exerted on a base of the tool may be less because the tip of the tool is offloading some of the force from the base. 
     At least one aspect of the present disclosure is directed to a system to calibrate position detection for a tool. The system can include base coupled to the tool. The base can be in contact with a working surface. The system can include a computing device having one or more processors. The system can include a sensor communicatively coupled to the computing device. The system can include a motor controlled by the computing device. The computing device can identify, via the sensor, a first value of a parameter indicative of an amount of force exerted by a portion of the base on the working surface. The computing device can instruct the motor to extend the working member towards a working surface. The computing device can identify, via the sensor upon the working member contacting the working surface, a second value of the parameter. The computing device can compare the first value of the parameter with the second value of the parameter to generate a difference between the first value and the second value. The computing device can determine a z-axis position of the working member relative to the working surface responsive to the difference between the first value and the second value greater than a threshold. 
     At least one aspect of the present disclosure is directed to a method of evaluating a position of a working member of a tool. The method can include a sensor communicatively coupled to a computing device comprising one or more processors detecting a first value of a parameter indicative of an amount of force exerted by a portion of a base of the tool on the working surface. The method can include a motor controlled by the one or more processors of the tool extending the working member towards the working surface. The base can be at least partially in contact with the working surface. The method can include the sensor detecting a second value of the parameter when the working member contacts the working surface. The second value of the parameter can be less than the first value of the parameter. The method can include the computing device determining a z-axis position of the working member relative to the working surface responsive to a difference between the first value and the second value greater than a threshold. 
     At least one aspect is directed to a system to position a working member of a tool. The system can include a base coupled to the tool. The system can include a computing device comprising one or more processors. The system can include a sensor communicatively coupled to the computing device. The system can include a motor controlled by the computing device. The system can include the computing device configured to identify via the sensor, a first value of a parameter indicative of an amount of force exerted by a portion of the base towards a working surface. The computing device can instruct the motor to extend the working member towards the working surface. The computing device can identify, via the sensor with the working member in contact with the working surface, a second value of the parameter. The computing device can compare the first value of the parameter with the second value of the parameter to identify a difference between the first value and the second value. The computing device can determine a z-axis position of the working member relative to the working surface based on the difference between the first value and the second value greater than a threshold. 
     At least one aspect is directed to a method of positioning of a working member of a tool. The method can include detecting, by a sensor communicatively coupled to a computing device comprising one or more processors, a first value of a parameter for a first vertical position of a base of the tool. The method can include extending, by a motor controlled by the computing device, the working member towards the working surface. The method can include detecting, by the sensor with the working member in contact with the working surface, a second value of the parameter indicating a second vertical position of the base of the tool. The method can include comparing, by the computing device, the first value of the parameter with the second value of the parameter to determine a change in vertical position of the base of the tool. The method can include determining, by the computing device, a z-axis position of the working member relative to the working surface based on the change in the vertical position of the base of the tool. 
     At least one aspect is directed to a system to position a working member of a tool. The system can include a base coupled to the tool. The system can include a computing device comprising one or more processors. The system can include one or more sensors communicatively coupled to the computing device. The system can include one or more motors controlled by the computing device. The computing device can determine, via the one or more sensors, a z-axis position of the working member. The computing device can provide, based at least in part on the z-axis position of the working member, motor control information to control the one or more motors to move the working member from a first location to a second location, the tool advanced in a direction that is within a range adjacent to a predetermined path for the working member of the tool. 
     At least one aspect is directed to a system to position a working member of a tool. The system can include a base coupled to the tool. The system can include a computing device comprising one or more processors. The system can include one or more sensors communicatively coupled to the computing device. The system can include one or more motors controlled by the computing device. The system can include a cavity of the tool to move particles of material removed from the working surface by the working member. The computing device can determine, based on first information received via the one or more sensors, a first location of the working member. The computing device can compare the first location of the working member with a predetermined path to determine a second location for the working member of the tool corresponding to the path. The computing device can provide, based on the second location, motor control information to control the one or more motors to move the working member from the first location to the second location, the tool advanced in a direction that is within a range adjacent to a predetermined path for the working member of the tool, the cavity configured to move the particles of the material in a direction opposite to the direction in which the tool advances. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is an illustrative example of an embodiment of an apparatus for automatically guiding tools. 
         FIG.  2    is an illustrative example of an embodiment of an apparatus for automatically guiding tools following a target path area and performing a task according to a planned design. 
         FIG.  3    is an illustrative block diagram of an embodiment of a system for automatically guiding tools. 
         FIG.  4    is an illustrative flow chart of an embodiment of a method for automatically guiding tools. 
         FIG.  5    is an illustrative flow chart of an embodiment of a method for automatically guiding tools. 
         FIG.  6    is a block diagram illustrating a general architecture for a computer system that may be employed to implement various elements of the systems, apparatus and the methods disclosed herein, in accordance with an embodiment. 
         FIGS.  7 A- 7 B  are illustrative diagrams of locating markers that may be employed to implement various elements of the systems, apparatus, and the methods disclosed herein, in accordance with an embodiment. 
         FIGS.  8 A- 8 B  are an illustrative example of an embodiment of an apparatus for directing or extracting dust particles that may be employed to implement various elements of the systems, apparatus, and the methods disclosed herein, in accordance with an embodiment. 
         FIGS.  9 A- 9 B  are an illustrative example of a top perspective view of an embodiment of a base plate for directing or extracting dust particles that may be employed to implement various elements of the systems, apparatus, and the methods disclosed herein, in accordance with an embodiment. 
         FIG.  9 C  is an illustrative example of a bottom perspective view of an embodiment of a base plate for directing or extracting dust particles that may be employed to implement various elements of the systems, apparatus, and the methods disclosed herein, in accordance with an embodiment. 
         FIG.  9 D  is an illustrative example of a top perspective view of an embodiment of a base plate for directing or extracting dust particles that may be employed to implement various elements of the systems, apparatus, and the methods disclosed herein, in accordance with an embodiment. 
         FIGS.  10 A- 10 B  are an illustrative example of an embodiment of a system for determining a location of a tool tip that may be employed to implement various elements of the systems, apparatus, and the methods disclosed herein, in accordance with an embodiment. 
         FIGS.  10 C- 10 D  are an illustrative example of an embodiment of a force sensor positioned on an apparatus for determining a location of a tool tip that may be employed to implement various elements of the systems, apparatus, and the methods disclosed herein, in accordance with an embodiment. 
         FIGS.  11 A- 11 B  are an illustrative example of directing or extracting dust particles using various elements of the systems, apparatus, and the methods disclosed herein, in accordance with an embodiment. 
         FIG.  12    is an illustrative example of a block diagram depicting a method of positioning a working member of a tool, in accordance with an embodiment. 
         FIG.  13    depicts a front view of a tool in accordance with an embodiment. 
         FIG.  14    depicts a front view of a tool without a working member attached in accordance with an embodiment. 
         FIG.  15    provides a side view of a tool with a working member attached in accordance with an embodiment. 
         FIG.  16    provides a side view of a tool without a working member attached in accordance with an embodiment. 
         FIG.  17    provides a rear view of a tool with a working member attached in accordance with an embodiment. 
         FIG.  18    provides a rear view of a tool without a working member attached in accordance with an embodiment. 
         FIG.  19    provides a top view of a tool with a working member attached in accordance with an embodiment. 
         FIG.  20    provides a top view of a tool without a working member attached in accordance with an embodiment. 
         FIG.  21    provides a bottom view of the internal stage and pivot components of a tool in accordance with an embodiment. 
     
    
    
     DETAILED DESCRIPTION 
     The present disclosure relates generally to systems and methods for working on a surface such as woodworking or printing. In some embodiments, the present disclosure relates to determining the location of a tool in reference to the surface of a material and using the location to guide, adjust or auto-correct the tool along a predetermined path or design plan such as, e.g., a cutting or drawing path. In some embodiments, the reference location may correspond to a design or plan obtained via an online design store. 
     In some cases, the present disclosure can facilitate evaluating a position of a working member of a tool. Evaluating the position of the working member can include, for example, determining the geometry of the cutting tool or determining the geometry of a work piece (e.g., working surface). 
     Determining the geometry of the tool can include or refer to determining the position of the tool tip (e.g., working member) relative to a reference frame of the tool. Determining the geometry of the tool can include or refer to determining the diameter of the cutting tool. The tool geometry information can be used to automatically determine a length of a cutting flute of the working member and an angle of the cutter (e.g. a V carving bit or helix angle). 
     Determining the geometry of a work piece can include or refer to determining or measuring the thickness of the material to be cut, or creating a topological map of a surface by repeatedly probing it with a tool tip. The tool can determine the location of features of interest such as holes on a work piece. 
     The present disclosure can use one or more techniques to determine the position of the working member or tool tip relative to the reference frame of the tool (e.g., tool height). For example, the tool can include a tool tip or working member and a base. The base of the tool can rest on and be in contact with a working surface. A technique to determine the position of the tool tip can include extending or dropping the tool tip onto the work surface (or a convenient flat surface such as a table) while measuring the weight on the base of the tool. When the tool tip makes contact with the work surface, weight can be transferred onto the tool tip and off of the base of the device as additional downward motion of the cutting tool occurs. The tool can detect this reduction in weight on the base by weight sensors in the base. This technique can provide improved accuracy in determining the position of the tool tip because the tool tip position can be determined within a fraction of the tool travel necessary to lift the base of the device off of the work surface. In some cases, where the tool tip can be quite sharp, the tool tip can sink or enter into the work surface (e.g., wood) a distance before generating sufficient force to cause the device to lift. However, since the weight sensors can be configured to detect even a small force reduction (e.g., 1%, 2%, 3%, 5%, 0.5%, 0.1%, or 10% of the force exerted by the tool or base on the material prior to the tool tip contacting the working surface), the tool can detect the change in force as the tool tip contacts the working surface even if the tool tip is to at least partially enter the working surface. 
     Furthermore, the tool can determine the position of the tool tip with this technique without performing an absolute calibration of the weight sensors because the tool can determine the position based on detecting a change in the force. Therefore, it can be possible to determine the position of the tool tip using inexpensive and uncalibrated force sensors. Examples of force sensors can include force-sensitive resistors, capacitive force sensors, high-pass sensors or piezo-resistive sensors. 
     The tool can detect when the tool tip or working member contacts or comes into contact with the work surface by detecting, noticing, determining, or otherwise identifying a lift of the base. The lift of the base may be a relatively small lift (e.g., a reduction in force on the force sensor of 0.1%, 0.5%, 1%, 2%, 5%, 10%, 15%, 20% or some other percentage based on the resolution or granularity of the force sensor). In some cases, the tool can detect the lift based on a tilt of the base (e.g., 1 degree angle, 2 degree, 5 degrees, 10 degrees, 15 degrees, 25 degrees or some other tilt that is detectable). The tool can detect the tilt using a camera, visual information, gyroscope, or 3-axis accelerometer. For example, the camera can determine shift in the captured image corresponding to a tilt resulting from the base lifting. The camera can take a first picture or image before the tool brings the tool tip into contact with the working surface, and then take a second image when the tool tip contacts the working surface. The camera can compare the first image with the second image to identify a tilt or variation between the two images. The accelerometer can indicate the tilt responsive to a motion or sudden motion caused by the base lifting. In some embodiments, the tool can include a force sensor in the tool mount to directly measure the force on the cutting tool tip. 
     The tool can determine or detect additional information about the tool including tip or working member position, diameter, or tool geometry. For example, the tool can include a break-beam sensor (e.g. laser break beam sensor, infrared break beam sensor, photoelectric sensor, or optical sensor). The working member can be dropped into the line of action of the sensor and the tool can detect the position of the working member when the working member breaks the beam. In some cases, the axis of the beam can be pre-calibrated relative to the coordinate frame of the tool. However, it may be challenging to accurately detect the tip position with this technique based on the tip geometry (e.g., if the tip shape is not flat across). 
     The tool can determine the proximity of the tool tip to the working surface using a capacitive sensor or an electromagnetic sensor. For example, the electromagnetic sensor can sense or detect a change in inductance of a sensing coil in the proximity to the tool tip or working member that includes metal by sensing eddy currents induced in the metal. 
     Another approach is to use a vision camera aimed at the tool to determine the position of the working member or tool tip. The vision camera can be pre-calibrated to the tool coordinate frame to detect the tool tip. In some cases, the vision camera can include a linear charge coupled device (CCD) sensor or other image sensor. A linear CCD sensor may use less processing than a vision camera to detect the tool tip. 
     The tool can measure the tool diameter using one or of these techniques. The tool can shift the tool tip around while measuring or determining the position of the tool tip. By shifting the tool tip, the tool can use a single break-beam sensor to detect tool diameter by passing the tool left-to-right through the sensor. The lateral motion of the tool can cause a first break and then unobstruct the beam to provide a measure of the tool diameter. Since router bits can have helical flutes, the tool can perform multiple measurements along the length of the tool to determine the diameter. The tool can determine the diameter using eddy currents or capacitive sensing with a one-dimensional sensor to gather multi-dimensional information about the tool geometry by correlating the sensor data to the tool position. The tool can determine additional information about the tool tip such as tip angle in the case of a v-cutting bit. Furthermore, the tool can include a vision camera to detect geometric properties of the tool. 
     The tool can measure the geometry of the work surface by correlating the tool tip position with device position on the plane of the work surface. To do so, the tool (e.g., a cylindrical tool with a conical or spherical tip) can first be related to the reference frame of the tool by detecting the position of the tool tip. Once the position of the tool tip is known relative to the tool&#39;s reference frame, the tool can be positioned laterally over a surface of interest (e.g., working surface) to determine the vertical position of the working surface. The vertical position of the working surface can refer to a recess, cavity, indent, or concave portion in a piece of wood whose depth is of interest. The tool tip can then be inserted, extended, lowered, plunged otherwise moved until the tool tip contacts the bottom of the recess. The additional displacement of the tool tip beyond the top portion of the surface where the tool tip first contacted the work surface indicates the depth of the recess. If the surface profile of the recess was of interest, the tool might be moved around the recess to multiple points. The tool can determine, at each of the multiple points, the depth. The tool can record both the depth and lateral position of the tool (e.g., x, y, and z coordinates, where x and y coordinates can refer to the lateral position and the z coordinate can refer to the depth). The lateral motion could be accomplished automatically using a built-in positioning stage, or performed manually by the user, or a combination of both. 
     Another potential application could be to find the center position of holes on a work surface. A tool with a conical tip can be fitted into the device. The tool can then be positioned approximately (e.g., within 5%, 10%, 15%, 20%, 25%, 30%, 50%, 75%, or 90% of the diameter of the hole) over the center of the hole, and plunged until the tip contacts the circle of the hole. Because the tool tip can be conical, the tool tip can cause the tool to center over the hole. The tool can then determine the lateral position (e.g., x and y coordinates) using, for example, a vision system to ascertain the position of the hole. 
     The tool can determine a thickness of a working surface or other piece of material. Using the determined thickness of the working surface, the tool can automatically set cutting depths or update cutting paths that may be dependent on the material thickness (e.g., a box joint where the length of the fingers are to correspond to the thickness of the mating material). The tool can determine or measure the thickness of the material hang or place the tool or portion thereof over an edge of the working surface or material, and then extend the tool tip until it contacts the surface supporting the material. The depth the tool tip extends beyond the top of the work surface in order to contact the surface supporting the working surface can indicate the thickness of the working surface. 
     The tool can determine a location of the tool or tool tip relative to a surface of a working material using location markers that may include contour trees, binary images, fiducial markers, or dominoes. The present disclosure facilitates directing and extracting dust away from a portion of the tool by generating airflow that directs the dust via one or more channels in a portion of the tool. The present disclosure facilitates determining a height of the tip of the tool using force sensors that detect a reduction in force when the tip of the tool touches the material. 
     With the determined information, the tool can be configured to guide a working member of the tool to perform a task on a target material (e.g., working surface). In some embodiments, a system may automatically guide a tool to perform the task. For example, in some embodiments, the present disclosure provides a handheld system that can identify the location of a tool, or a rig that contains a tool, relative to the material being worked. In some embodiments, the device may be non-handheld; e.g., the device may be on a movable platform such as a remote control platform, robotic platform, or another type of movable platform that may or may not be controllable. The system may adjust the location of the tool (or provide instructions for the adjustment of the location of the tool) based on or responsive to the current location of the tool and a desired location corresponding to a design plan. In some embodiments, the system includes a handheld device with a working instrument capable of being operated by hand which can make precision adjustments of the working instrument location based on spatial location to provide an accurate path which the working instrument travels. 
     In some embodiments, systems and methods disclosed herein can include a location detection system or perform one or more location detection techniques that can detect the current location or position of a tool on a target material accurately, robustly, or with low latency. For example, a video or sill image camera coupled to the tool and accompanying control circuitry may be used to scan the surface of the material and process the scanned data or scanned image data to generate a digital map of the surface of the material in advance of performing a task on the material. When the tool is brought near the surface of the material during performance of a task on the material, the camera may take a second image and compare the second image with the digital map to detect a location of the tool relative to the material. 
     In some embodiments, various location detection techniques may be used including, e.g., integrating wireless position sensing technologies, such as RF, near field communication, Bluetooth, laser tracking and sensing, or other suitable methods for determining the position of the tool and facilitating guiding or adjusting the position of the tool to perform a task. In some embodiments, the system may include a hybrid location detection system that employs two or more location detection techniques to determine the location of the tool. For example, each location detection technique may include orthogonal strengths and weaknesses, but when combined, can detect a location with high accuracy and low latency. For example, a first location detection technique may be high accuracy but low frequency (e.g., a sensor configured to obtain data once per second that accurately determines the position but has high latency). The first location detection technique may be combined with a second location technique that includes a sensor that provides location information with high frequency and high accuracy but provides limited information (e.g., an optical mouse sensor that is high frequency and high accuracy but only provides dead reckoning including direction and speed of movement rather than the location of the tool in a global context). In an illustrative example, the hybrid location system may use a camera to obtain an image to determine a position of the tool on the surface of the material accurately, and then use an optical mouse sensor to track the change of the position until the next frame of the image comes in. In this example, the second location technique using the optical mouse sensor may not provide all location tracking because integrating velocity to determine a position may accumulate error over time, or the device would not be able to determine a location if the device was picked up and put it down at a different position. 
     In some embodiments, to generate the map in advance of the cutting or drawing operation, a user may sweep the surface of a material with a camera until the camera has obtained images of all, substantially all, or a portion of the surface of the material or desired portion thereof. The system may obtain these images and stitch the images together to produce a cohesive map. Generating the digital map image and detecting the location may include one or more image processing techniques, pattern recognition techniques, localization techniques, computer vision techniques, for example. For example, the system may identify that points A and B in a first image correspond to point C and D in a second image and accordingly stitch the two images. For example, on a wood surface, the system may identify variations, bright spots, color variations, marks, fiduciary markers, binarized images, or wood grains in the image and compare them with the digital map to determine a location. In another example, the system may further use corners, sides, lighting patterns, or other signal capable of identifying a location. 
     The material can be marked to facilitate mapping of the surface of the material or detection of a position of the tool on or proximate to the material. For example, the surface of a material, such as metal or plastic, may not contain sufficient identifying marks to accurately detect location. Distinguishing marks or markers can be added to the material to facilitate location detection techniques such as pattern recognition or image processing. The markers can include any type of material, ink, tape, light, laser, carving, engraving, temperature gradient, invisible ink (e.g., ink only visible under ultraviolet or other wavelengths of light) capable of facilitating a location detection technique. In some embodiments, the marker includes a tape that can be applied to at least a portion of the surface of the target material. The tape may include symbols such as a unique barcode, design, pattern, colors, engravings, raised bumps or depressions, for example. In some embodiments, the marker may include a user randomly marking on the target material with a pen, pencil, ink, invisible ink, paint, crayons, or any other marking or writing instrument. 
     In addition to generating a digital image of the surface of the material, in some embodiments, the system may identify a cutting or drawing design plan on the surface of the material. A design plan may include any cutting or drawing a user of the system desires. For example, the design plan may include a freehand design, tracing, picture, image, design generated using computer-aided design (“CAD”) software, purchased design, or a purchased electronic design. The design plan can be a design of an object that the tool can create by performing an operation on the material, such as a design for a table that can be cut from at least one piece of wood. 
     The system can incorporate the design plan with the map image or otherwise relate the design plan with a map of the surface of the material or overlay the design plan on the map image. In some embodiments, the design plan may be drawn on the surface of the material before or after generating the initial map of the material (e.g., using a special pen whose ink can be detected by the system using ultraviolet or other wavelengths). If, for example, the surface of the material includes a design (e.g., a cutting design or drawing design) during the initial mapping phase, the system may process the image to identify the design plan and include it in the digital map of the surface of the material. If the design is drawn or otherwise marked on the surface of the material after generating the initial map, the system may obtain images of the material with the design by using the camera to rescan or take new images of the material. If the design is drawn or otherwise marked on the surface of the material before generating the initial map, the system may identify the design as a cutting or drawing design plan or a user may indicate to the system that the identified design is a cutting or drawing design plan. 
     In some embodiments, a digital design may be added to digital map of the surface of the material without physically adding the design to the surface of the material or otherwise marking the actual material with a design. For example, the digital design may be generated on a computer and may include a CAD drawing or any other type of drawing (e.g., JPEG, BMP, or GIF). Using CAD software, for example, a user may modify the map image by adding the design plan. Any other suitable software may be used to incorporate a design plan onto the map image or otherwise relate a design plan with a map of the surface of the material (e.g., data that indicates a location of the design plan used to facilitate the performance of a task on a material). After registering the design on the digital map or digital map image, the system may provide the corresponding digital map data or digital image data with the design plan to the tool. In some embodiments, the system may display the map image with the design on a display device of the tool to facilitate a user performing a task on the material. In some embodiments, the tool may perform the task in accordance with the design plan without displaying the design plan (e.g., the tool may automatically perform an aspect of the task or the tool may not include a display device). 
     During the cutting or drawing operation, a user may place the tool on or near the surface of the material. Upon placing the tool on the surface, the camera may re-scan or take an image of a portion of the surface of the material. The image may correspond to a portion of the material that is at a location different from the cutting or drawing tool. The system may determine the location of the tool relative to the surface of the material or the design plan by comparing identifying marks in the new image with identifying marks in the map image generated in advance of the performance of the task on the material. The camera may be mounted or otherwise coupled to the tool such that image capturing aspect of the camera (e.g., lens) is directed on the surface of the material at a fixed and known vector from the cutting tool (e.g., drill bit). By focusing the camera away from the cutting tool, the system may obtain images that are relatively clear of debris caused by cutting that may obfuscate the markers used for detecting a location. 
     The system may compare the new images with the digital map of the surface of the material to determine a precise location of the tool. For example, the portion of the digital map corresponding to the top right corner may include a set of identifying marks. Upon obtaining the new image, the system may identify those same identifying marks and determine that those marks correspond to the top right corner of the map image. The system may then determine, based on the camera vector offset, the precise position of the cutting or drawing tool. 
     In some embodiments, the system may display, in real time, the precise position of the cutting or drawing tool on a display device (e.g., a display device of a tool or a remote display device communicatively coupled to the system or tool). The system may indicate the position on the display via an “X”, circle, dot, icon, or using any other indication to signal a current position of the tool. In some embodiments, the tool may overlay the indication of the current position on the design plan or cutting path (e.g., a predetermined path). In some embodiments, the tool may overlay the indication of the current position on the map image. In some embodiments, the tool may overlay the indication of the current position on the map image that includes an overlay of the design plan. 
     In some embodiments, the system may include a positioning system that adjusts or moves the tool based on a detected location of the tool and a design plan. In some embodiments, the system can use various location detection techniques to detect the location of the tool, and use various positioning techniques to move or adjust the location of the tool. For example, the system can include a hybrid positioning system that includes two or more positioning systems to position a tool. Upon determining the location of the tool and a desired location for the tool, the first positioning system may be configured to move, adjust, or position the tool over a relatively large range (e.g., move the tool to anywhere on the work area or surface of the material), but with relatively low accuracy. The second positioning system may be configured to move, adjust, or position the tool over a relatively short range (e.g., within a radius of 5 inches of the current location of the tool), but with high accuracy. In some embodiments, the first (e.g., coarse or rough) positioning system may include a human positioning a tool on the surface of a material, and the second (e.g., fine or precise) positioning system may include positioning the tool using servo motors, stepper motors, actuation mechanisms, or eccentrics, for example. The first positioning system can include non-human positioning systems such as, robotic systems, remote control systems, or Global Positioning System (“GPS”) enabled devices. 
     For example, the first positioning system may include a long-range, low-accuracy positioning mechanism that is configured to move, adjust or correct the position of the tool based on the design plan. The second positioning system may include a short-range, high-accuracy positioning mechanism that can move, adjust or correct the position of the tool, within a maximum range, more precisely than the first positioning mechanism based on the design. In an illustrative and non-limiting example, the first positioning system may include, e.g., a maximum range that includes the range of the entire work area (e.g., the area comprising the surface of the material on which the task is to be performed), and include an accuracy of +/−0.25″. The second positioning system may include, e.g., a maximum range of 0.5″, with an accuracy of +/−0.01″. The maximum ranges and accuracy of the first and second positioning systems may include other range and accuracy values that facilitate systems and methods of hybrid positioning. In various embodiments, range and accuracy may refer to one-dimensional accuracy (e.g., along an X-axis), two-dimensional accuracy (e.g., X-Y axes) or three-dimensional accuracy (e.g., X-Y-Z axes). 
     The first positioning system may be less accurate and include a positioning system where the maximum range is substantially greater than the maximum range of the second. For example, the first positioning system can move the tool from anywhere on the surface of the material to within +/−0.25 inches of a desired location, while the second positioning system can be configured to move the tool up to 5 inches from a current position, but with an accuracy of 0.01 inches. In some embodiments, the hybrid positioning system may include a plurality of positioning systems that are each configured to accurately determine a location and then position the tool to within a certain distance range such that, when the positioning systems are used together, the system can precisely determine a location and position or adjust the tool accordingly. In some embodiments, the maximum range of each subsequent positioning system may be equal to or greater than the accuracy of the previous positioning system. In an illustrative example, a first positioning system may be able to position the tool on the surface of the material with, e.g., a maximum range corresponding to the size of the surface of the material, and with an accuracy of +/−1 inch. A second positioning system may be able to position the tool on the surface of the material within a maximum of range of 2 inches with an accuracy of +/−0.1 inch. A third positioning system may be able to position the tool anywhere within a maximum range of 0.2 inches with an accuracy of +/−0.01 inch. Therefore, in this example, by using all three positioning systems together, the hybrid positioning system can precisely position the tool within a maximum range that includes the entire surface of the material or work area with an accuracy of +/−0.01 inch. 
     In some embodiments, the system may include automatic adjustment, guiding or error correction to facilitate performing a task in accordance with a design plan. The system may use various types of adjustment, guiding or correction mechanisms, including, e.g., eccentrics, servomechanisms, stepper motors, control loops, feedback loops, actuators, nut and bolt-type mechanisms. For example, the system may include eccentrics or servomotors coupled to a frame and the cutting tool configured to adjust the position of the cutting tool relative to the frame. Upon determining the current position of the cutting tool, the system may compare the current position with the desired position. The system may then guide the tool in accordance with the design plan. In some embodiments, when the system determines there is a discrepancy between the current position and the desired position, or the current position or trajectory deviates from the design plan, the system may adjust the cutting tool in accordance with the design plan. For example, the system may identify a cutting path or vector of the tool and the design plan and adjust the cutting tool such that the next cut is in accordance with the design plan. 
     The system may utilize various automatic correction mechanisms. In some embodiments, the system may include eccentrics configured to adjust the position of the cutting tool. For example, using two eccentrics, the system may adjust the position of the cutting tool in two dimensions. Eccentrics may include any circular widget rotating asymmetrically about an axis. For example, an eccentric may include a circle rotating about non-central axis. The eccentrics may be coupled to the cutting tool and the frame and be configured to adjust the position of the cutting tool relative to the frame, which may adjust the position of the cutting tool relative to the surface of the material. In some embodiments, the system may utilize a screw with a nut to change rotational motion to linear displacement to correct or adjust tool positioning. 
     In some embodiments, the system may include orientation control based on the type of cutting tool. For example, if the cutting tool is a saber saw that cannot be adjusted perpendicularly, the system may adjust the orientation or angle of the saber saw in accordance with a design plan. They system may include actuators configured to adjust the tilt or angle of the saw. 
     The system can control the z-axis of the cutting or drawing tool. The system can determine the position of the tip of the cutting tool relative to the work surface. By controlling the z-axis (e.g., an axis that is substantially orthogonal to a surface of the material; an axis that is vertical; an axis that is parallel to an axis along which the working member is lowered or raised to or from the surface of the working member or cutting tool) of the cutting or drawing tool, the system may start and stop cutting or drawing in accordance with a design plan. For example, if the cutting tool is beyond a correctable distance away from the design plan (e.g., outside the radius of automatic compensation), the system may stop the cutting by adjusting the z-axis position of the cutting tool (e.g., lifting the drill bit off the wood). When the user brings the cutting tool back to within the radius of automatic adjustment, the system may automatically adjust the z-axis position of the cutting tool such that cutting commences again (e.g., lowers the drill bit into the wood). The radius or range of compensation may correspond to a positioning system of the localization system, For example, if the localization system includes a hybrid positioning system that includes a large range and short range positioning system, the radius of compensation may correspond to the short range positioning system, In some embodiments, controlling the z-axis position of the tool may facilitate making 2.5 dimension designs. For example, a design plan may indicate z-axis information corresponding to the surface of the material. Thus, the system can use a determined z-axis position of the working member or cutting tool or tip thereof to control a motor to move the working member to a second location or position (e.g., x, y, or z axis position). 
     In some embodiments, the system may indicate to the user that the cutting tool is on the design path (e.g., a predetermined path) or within the range of compensation such that the system may correct the position of the cutting tool. In some embodiments, the system may indicate to the user that the cutting is not on the design path or not within the range of compensation. The system may further indicate to the user to correct the position of the cutting tool or a direction in which to move the cutting tool to bring it on the design path or within the range of compensation. The system may provide one or more indication visually via the display device, using light emitting diodes or other light sources, audio signal, beeps, chirps, or vibrations. In some embodiments, an indication that the tool is deviating from the design path beyond an acceptable range may include automatically shutting off the cutting machine or adjusting the z-axis of the cutting or drawing tool such that it stops performing a task on the material. In some embodiments, the system may indicate the design path on the material of the surface itself by, e.g., shining a beam of light indicating to the user where the design path is and where to proceed. For example, upon determining the error, the system may shine a beam indicating to the user how much to adjust to the tool in order to bring the position of the tool to within the range of automatic compensation or on the design path. 
     In some embodiments, a plurality of cutting or drawing tools may be used with the system including, e.g., saber saw, jig saw, router, or drill. The system may be configured such that users may use various aspects of the present disclosure with various cutting or drawing tools without making any adjustments to the tool or minor/temporary adjustments. For example, the system may include a frame, camera, display device, and computing device. The frame may be configured such that a cutting tool may be placed in the frame. The camera may be coupled to the frame or may be attached to the cutting tool. Upon placing the camera, the system may automatically or manually be calibrated such that the system obtains the vector offset between the camera and the cutting or drawing tool (e.g., the drill bit). 
     In some embodiments, the system may include a freestanding device configured to perform mapping and localization functions and indicate to a user the current position of the device. In some embodiments, the freestanding device may be attached to a cutting tool or drawing tool. In some embodiments, the freestanding device may not provide automatic correction functionality. In some embodiments, the freestanding device may include a display or a camera. In some embodiments, the freestanding device may determine a design path and detect when the tool is off the design path. The freestanding device may indicate the error by, for example, the display, shining a light on the surface of the material, audio signals, or voice narration. 
     Referring to  FIG.  1   , an illustrative example of an embodiment of an apparatus for guiding tools to perform a task is shown. In some embodiments, the device includes a frame and a tool (e.g., a router in the example of  FIG.  1   ) mounted within the frame. The frame may be positioned manually by the user. The device can adjust the position of the tool within the frame to guide or adjust the tool in accordance with a design plan or to correct for error in the user&#39;s coarse positioning. The device may also include a display and be configured to map the target material and display it on the display. In some embodiments, markers on the target material (e.g., stickers) may facilitate generating a map of the target material by providing differentiating features. The device may obtain a design or plan by downloading it from an online store. The device may display a map of the target material with the design that indicates the desired cutting pattern. 
     Referring to  FIG.  2   , an illustrative example of an apparatus for automatically guiding tools following a target path area and performing a task according to a planned design is shown. In some embodiments, to follow a complex path, the user of the device may need to only move the frame in a rough approximation of the path. In this example, the dotted line shows the path that the tool would take if its position were not adjusted; the solid line is its actual path, e.g., an outline of the southeastern United States. In this example, the user can grip the frame and guide the tool generally along the dashed line, and the tool can self-adjust to cut along the solid line. In some embodiments, the device automatically adjusts the drill bit or other cutting tool based on the position of the cutting tool (e.g., one or more of an x-axis position, y-axis position, or z-axis position) and the desired position of the cutting tool. The x-axis and y-axis can intersect to form an x-y plane that is substantially parallel (e.g., within 45 degrees) to the surface of the material, while the z-axis is substantially perpendicular (e.g., 45 degrees of being perpendicular) or orthogonal to the horizontal plane formed by the x-y axis. In some embodiments, the user of the device may move the device along the dotted line  1210  in  FIG.  2    (or the path  406  of  FIG.  23   ), while the device automatically adjusts the cutting tool (e.g., an x, y or z position) in accordance with the desired design plan, such as the design plan  1205  of  FIG.  2    For example, the device may identify or detect the current position of the cutting tool relative to the target surface with the design. The device may then compare the current position with the desired position of a design or map and adjust the cutting tool. For example, if the working member or cutting tool tip is determined to be 1 inch above the surface of the material, the system can determine to lower the cutting member tip to contact the surface of the material. In another example, if the design indicates to drill a whole 0.5 inches deep into the material, then the system can determine the z-axis position of the tip and insert the tip 0.5 inches into the material based on the determined z-axis position. For example, the system can instruct a motor to extend the working member or cutting tool 0.5 inches beyond the surface of the material. 
     Referring to  FIG.  3   , an illustrative block diagram of an embodiment of a system for automatically guiding tools is shown. In some embodiments, the system  680  includes a smart device  681 . The smart device  681  may include at least one central processing unit (“CPU”) or processor  683 , and may include software code  685  that performs one or more processes, at least on memory  687 , or at least one display  689 . The smart device  681  may include a self-contained unit or the smart device  681  may include components that are not self-contained or separated. For example, the display  689  may be tethered to the smart device  681  or integrated into the housing of the smart device  681 . In some embodiments, the smart device  681  may be integrated as part of the system  680  so that the system is a self-contained portable unit. 
     In various embodiments, the system  680  can include one or more sensors to facilitate determining a location of the tool (e.g., IR, lasers, ultrasonic range finding, etc.). For example, and in some embodiments, the system  680  can include a camera  682  that can be used in combination with the smart device  681  to build a map  684  of the material to be worked on. The camera  682  may be coupled or attached to any tool  699  to provide positioning for that tool  699 . In some embodiments, the camera  682  is coupled with a display  689  and CPU  683 . For example, the camera  682  may be part of a computer or smart device  681  that can be attached or coupled to any tool  699 . A software application or code  685  can be installed on a mobile smartphone and can utilize the camera, CPU, memory, and display of the smartphone. In some embodiments, one or more aspect of the software or processing may be performed by a field programmable array device (“FPGA”) or a digital signal processor (“DSP”). 
     In some embodiments, the camera  682  can take images with a high-frame rate. For example, the camera can scan the surface of the material to obtain scanned data or scanned image data. In some embodiments, the camera may scan the surface of the material and a processor can process the scan to generate scanned data that indicates a map of the surface of the material. This may facilitate location functions or mapping functions disclosed herein. The camera  682  can also take images with a relatively low-frame rate and the camera  682  can be coupled with one or more optical sensors (e.g., sensors in optical computer mice). The optical sensors may provide low-latency dead reckoning information. These optical sensors may be used in conjunction with the camera  682 . For example, the camera  682  may provide accurate global position information a few times a second and appreciable lag, and the optical sensors may be used to provide dead-reckoning information with low lag that fills in the time since the last image was taken. In some embodiments, accelerometers may be used for dead-reckoning. The system  100  may use multiple cameras to increase the accuracy or range of coverage when scanning, or to provide depth information. 
     In some embodiments, the system  100  is configured to build, generate or otherwise receive a map  684 . In some embodiments, the map  684  may be built using computer vision (“CV”) or sensors techniques. For example, a CV technique may be used to build a photo mosaic. A photo mosaic process may include taking multiple photographs of different parts of the same object and stitching at least two of the, photographs together to make at least one overall image covering the entire object. 
     In some embodiments, the system  680  or processor may be configured to evaluate the scanned data using a technique that includes simultaneous localization and mapping (“SLAM”). SLAM may include using a sensor that is communicatively coupled with a processor  683  and related software  685  to build a map  684  of the material being worked on (or “target material”) while determining (e.g., simultaneously) the location of the tool  699  relative to the map  684 . For example, after building at least a portion of the map, a camera  682  may capture images of the material being worked. The images may be fed to and processed by the smart device  681  to determine the location of the tool  699  or rig. The system  680  may analyze the captured images based on the map  684  to determine the location (e.g., geo location) of the camera  681  relative to the material. Upon determining the location of the camera  682 , in some embodiments, the system  680  may identify that the location of the rig is a known or determinable offset from the position of the camera  682 , which may be rigidly attached to the rig. 
     Various embodiments may use various other location processing and determining technologies including, e.g., integrating wireless position sensing technologies, such as RF, near field communication, Bluetooth, laser tracking and sensing, or other suitable methods for determining the position of the tool  699  on top of the work piece. For example, ultrasonic, IR range finding, or lasers can be used to detect the location of the tool relative to a work area or surface of a material. The detected location of the tool can be provided to any other component of the system  680  to facilitate guiding or adjusting the position of the tool in accordance with an embodiment. 
     In some embodiments, the system  680  may be configured to compute the location of the tool  699  relative to the rig using the current orientations of the motor shafts. For example, the system  680  may identify the orientations of the motor shafts by homing them and then tracking one or more acts taken since the homing process. In some embodiments, the system  680  may use encoders could be used instead of homing as the encoders would be able to tell the orientations of the shafts directly. Through the offsets and calculations, the system  680  can identify the location of the tool  699  or rig relative to the material being worked on. The captured images that can be analyzed against the map  684  may include, e.g., characteristics of the material such as wood grains and deformations or may include markers placed on the material. Various aspects of the mapping and location technology will be described in more detail below. 
     In some embodiments, the system  680  may receive a design  686  or template. For example, the smart device  681  may be configured to receive the design  686  or template from a user of the system  680 . The smart device  681  may include or have access to various input/output devices configured to receive the design  686 . In some embodiments, the system  680  may receive the design  686  via a network. In some embodiments, the user or system  680  may modify or adjust the design  686  based on the map  684 . For example, a user may adjust the size of the design  686  relative to the map  684  of the material in order to generate a desired working path on the material being worked on. In some embodiments, the system  680  may automatically adjust or optimize the size of the design based on the dimensions of the material. 
     The network may include computer networks such as the Internet, local, metro, or wide area networks, intranets, and other communication networks such as mobile telephone networks. The network can be used to access web pages, online stores, computers or data of a retail store that can be displayed on or used by at least one user device, system  680 , or system  100 , such as, e.g., a laptop, desktop, tablet, personal digital assistants, smart phones, or portable computers. 
     The system  680  may be configured to create, capture, or load designs  686  in a plurality of ways. In some embodiments, designs may be downloaded or otherwise obtained. For example, a user may generate a design on a computing device and transfer or otherwise convey the design to the system  680 . In another example, the system  680  may receive the design from a third party entity. For example, a user may purchase a design online via a network and upload the design to the smart device or computer  681 . In some embodiments, the system  680  may facilitate capturing a map of the surface and also of the design  686  on that surface. This may facilitate setting up the system  680  to follow a specific line or to show the user an image of the surface of the material underneath a large tool that obstructs sight, or to show the surface with a drawn plan in a pristine state before it is covered with debris or the surface on which the plan is drawn is cut away. In some embodiments, the design  686  could be designed, altered, or manipulated from its original form on the device  681  through a menu driven interface allowing the user to input distances, angles, and shapes or to free hand a drawing on a touch sensitive pad or display. 
     In some embodiments, while a user moves the system or rig  680  along the target material, the smart device  681  processes the captured images from the camera  682 , determines the location of the rig  680 , or provides a desired path to the user on display  689 . Once the user has placed the rig  680  close to the desired path, the rig or system  680  may automatically adjust the position of the tool  699  to achieve the desired working path in accordance with the loaded design  686 . The term “rig” and “system” may be used interchangeably as described herein. In some implementations, the rig includes the physical device and its attachments, and the system includes the physical device, its attachments, and related technology and software code embedded or included in some of the physical elements. 
     In some embodiments, the system  100  builds the map  684  based on images captured by the camera along an arbitrary path of the target material until the entire area of interest has been covered. For example, a user may sweep the camera  300  in an arbitrary path over the surface of the material until the entire area of interest has been covered. In some embodiments, the system  100  can be configured such that the camera  682  can be removed from the rig  100  to sweep or pass over an area of the material. The system  100  may stitch together the images obtained by the camera  682 . For example, the system  100  may use an image mosaic software code  685  to form a cohesive map  684  of the area of interest of the surface of the material. The system  100  may store the map  684  in memory  687 . Upon receiving an image taken by the camera  682  of mapped material, the system  100  can compare the image with the map  684  held in memory  687  and may further determine a position and orientation. For example, the system  100  may determine, based on the comparison, the position of the tool, drill, system, cutting member, stage, or rig. 
     In some embodiments, the system  680  may allow a user to create and load a design  686  after the map  684  has been assembled. For example, after the map  684  has been assembled on the smart device  681  (such as a computer), the user may create a design  686  on the computer by plotting it directly on the generated map  684 . For example, the user may mark positions on a piece of wood where a drill hole is desired. The techniques and features of the software code  685  (include computer aided design and manufacturing) can be employed to create a design with accurate measurements. Then, when the user returns to the material, the position of the camera  682  on the map  684  may be displayed on a screen or display  689  to the user, with the design plan  686  overlaid on the map  684 . For example, the system  680  can display on the display device a map image overlaid with an indication of a position (e.g., position of the sensor, device, cutting tool or drawing tool) relative to the surface of the material. In some embodiments, the system  680  may identify the geo location of the tool relative to the map. For example, the camera  682  may be attached to a drill and used to determine the position of the drill exactly relative to target drill locations specified in the design  686 , facilitating the user to line up the drill more precisely. 
     In some embodiments, the system  680  is configured to build the map and track the camera&#39;s position using visual features of the target material. In some embodiments, the software  685  includes instructions to build the map and track the camera&#39;s position using visible features of the material such as grains, imperfections, or marks. The target material may be altered to facilitate mapping and tracking functions. For example, solid colored plastic may be too undifferentiated for the system  680  to effectively map or track. Therefore, a user may, e.g., alter the material surface in some way to add features that can be tracked. In another example, the system  680  may instruct a marker to arbitrarily add features that can be tracked. For example, features that may be added may include ink to the material that is typically invisible, but which can be seen either in a nonvisible spectrum or in the visible spectrum when UV or other light is applied, allowing the camera to track the pattern of the invisible ink while not showing any visible markings once the work is done. In some embodiments, the user may apply stickers with markers which can later be removed. Features could also be projected onto the material such as with a projector. Or, if the user will later paint over the material or for other reasons does not care about the appearance of the material, the user could simply mark up the material with a pencil or marker. 
     In some embodiments, the marker tape or stickers may include a unique sequence of barcodes over the entire length of the tape. In some embodiments, the marker tape may be thin such that the device may pass over the marker tape without getting stuck or disturbed. In some embodiments, the tape may be designed and constructed such that it will stay down as the device moves over the tape, but can also be easily taken off upon completion of the project. Marker tape materials may include, for example, vinyl or any other suitable material. 
     In cases where the camera cannot track the material, or cannot do so accurately enough, or the material is unsuitable for tracking (e.g. due to an uneven surface), or any other reason that prevents the camera tracking the surface directly, the camera may track other markers off of the material. For example, the user may put walls above, below, or around the sides of the material being worked on that have specific features or marks. The features or marks on the surrounding surfaces may enable the camera to determine its position on or relative to the material. In various embodiments, different types of positioning technology or devices may be used to locate the tool  699  or stage  690 , possibly in conjunction with a camera  682  that is used mainly for recording the visual appearance of the material without needing to perform the tracking function. Positioning technology may include, e.g., ultrasonic, IR range finding, or lasers, for example. 
     The system  680  can adjust the precise location of the tool  699  by adjusting the geo location of the stage  690  or a moveable platform to which the tool  699  is attached. The stage  690  may be connected to an eccentric coupled to a motor shaft. As the motor shaft moves in a circular path the eccentric moves the stage  690  in complex arcs and paths. A pivot  694  may be connected to the stage and is also connected to an eccentric coupled to a second or pivot motor shaft. The pivot  694  may be configured to pull or push the stage  690  to achieve controlled movement of the stage within a 360 degree range. By controlling the rotation of the eccentrics, the system  680  may position the stage in almost any XY position in the range. 
     In some embodiments, the system  680  uses a reference lookup table to facilitate guiding the tool. For example, a reference look table may include motor coordinates related to desired stage positions. In some embodiments, the system  680  may compute calculations that can be used to adjust the motors that move the stage  690  and the cutting bit of the tool  699  connected to the stage  690  to the desired location. In some embodiments, the system  680  may move the tool  699  360 degrees in a two dimensional plane by positioning the stage  690  and pivot  694 . For example, the cutting instrument of the tool can be moved anywhere within the 360 degree window of the target range  408 . 
     In some embodiments, electric motors may move, position or adjust the stage  690  and pivot  694 . A stage motor controller  691  may control the stage motor  210 . A pivot motor controller  695  may control the pivot motor  220 . The stage motor controller  691  and pivot motor controller  695  may receive information that includes the desired location or coordinates from the smart device  681 . Based on the received information, the stage motor controller  691  and pivot motor controller may  695  activate and control their respective motors  210 ,  220  to place the stage  690  and the pivot  694  in the proper or desired position, thereby positioning the tool in the desired geo location. 
     In some embodiments, the smart device  681  may communicate with, receive information from, and control the tool  699 . For example, the smart device  681  may send instructions to power on or off or increase or reduce speed. In some embodiments, the instructions may signal when to engage the target material by, e.g., adjusting the depth of the tool  699  when the user is close enough to or near the desired path on the material. 
       FIG.  4    provides an illustrative flow chart of an embodiment of a method  600  for performing a task on a target material. For example, the method  600  may facilitate cutting a working surface using a router based embodiment. In some embodiments, at act  602  the user may find or create a design they want to cut out of a material. In some embodiments, the task may include a plurality of tasks (e.g., a first task and a second task that may be a subset of the entire task). For example, the task of cutting the design out of the material may comprise a first task of cutting a first portion of the design and a second task of cutting a second portion of the design. In some embodiments, the first and second task may be substantially similar (e.g., same type of cutting or drawing tool), while in other embodiments the first and second task may differ (e.g., different drill bit or drawing tool, different type of cutting tool, different user device, different area of the material, etc.). 
     Prior to or subsequent to identifying the design plan, the user may map the surface of the material or sheet of material. If the material has enough markings the user may use the material itself. However, in act  604 , if the material has a flat surface or limited markings the user can place markers on the material. Markers may include, e.g., printer marker stickers or other type of suitable indicia capable of being readily identified. 
     In some embodiments, at act  606 , a sensor may scan the material to obtain scanned data. For example, a camera scans the material and the various markers to create the map. The CPU may process the images captured by the sensor or the camera and generate the map or scanned data. The size and shape of the map can be appropriately manipulated to a preferred configuration. In some embodiments, at act  608 , the design is registered or otherwise related to the map to create a cutting plan. 
     In some embodiments, at act  610 , the cutting tool is prepared to perform the task. For example, a user may load, adjust, or secure the bit, mount it to the rig and turn the router on. In some embodiments, the system may turn on the router via a software initiated process in response to one or more parameters, including, e.g., motion sensing of a movement of the rig  100  in a particular direction by the user. 
     In some embodiments, at act  612 , the system may receive various settings. For example, the user may set the width of the bit of the cutting tool, the range (e.g., area) of the tool&#39;s desired range correction, the size of the cross-hair, or the speed of the cutting tool. Thereafter, instructions may be provided to the software to begin the task. 
     In some embodiments, at act  614 , the rig is placed adjacent to the desired path so that the system can automatically adjust the position of the tool into a starting adjustment range position along the desired path. The user may then follow the constant speed strategy as described herein, for example with regards to  FIG.  3   . In some embodiments, once the tool has advanced fully around the plan (act  616 ) the user can remove the device and work product from the material. 
       FIG.  5    shows an illustrative flow chart of an embodiment of a method  650  for the constant speed strategy. The process in  FIG.  3    assumes the user already has the router attached to the rig and has mapped their material and loaded up their design. In some embodiments, at act  651 , the user starts the process to cut the material. The process can include moving the tool to a spot within the range of plan or path on the material (act  653 ). For example, a user may move the tool or the tool may be remotely controlled. 
     In some embodiments, the process includes determining, based on the location of the tool, whether there is a point on the plan within the adjustment range of the rig (act  655 ). In the event that there is no point within range, the process may include sending a notification (e.g., via the display, audio, vibration, light, or LED) and waiting until the user moves the device within the adjustment range (act  657 ). 
     In some embodiments, if there is a point within the adjustment range, the process includes, at act  659 , setting the point on the plan nearest to the tool as the target point. In some embodiments, the process may include moving the tool to the target point and cuts the material (act  661 ). 
     In some embodiments, the process includes creating a second target by determining if a new target is within the adjust range (act  663 ). If there is a second target, the process may include setting the second target point as the new target (act  665 ). The device may continue to move in a clockwise direction, cutting from the old target point to the new target point. In some embodiments, the process may include identifying the next target point within the adjustment range (act  663 ) while the tool or router is cutting from the old target point to the new target point. For example, the determination am optimum or desired second target may be continuous, and based on the image, or various images, detected from the camera and processed by the system. 
     If there is no target point within range, in some embodiments, the process includes clearing the target point (act  667 ) and starting at act  655  to determine whether there is a point on the plan within the adjustment range. In some embodiments, this process continues until the tool has gone through the all or part of the plan in a particular direction, such as a clockwise direction. 
     In some embodiments, the mapping phase may be bypassed if the material size is greater than the design. For example, the user may determine a starting point that corresponds with a region on the design (i.e. the top right corner) and the system  800  may start painting the image. 
     The embodiments discussed herein so far have focused on rigs that accommodate a tool being attached to a stage and the stage is moved or controlled by one or more motors. The linear design depicts a router moved by a motor where the router is connected to a linear stage. In such instances, the router is attached or mounted as a separate unit. However, the system can be designed as one unit where the stage, motors moving the stage, controllers, and all within the same housing and within the same power system as the housing and power of the tool. By way of example, the router housing would be enlarged to fit the stage and motors and might include a display integrated into the housing. Through such an embodiment, the form factor might be improved to look like a one piece tool. 
     The embodiments presented here are not meant to be exhaustive. Other embodiments using the concepts described herein are possible. In addition, the components in these embodiments may be implemented in a variety of different ways. For example, a linear stage, or a hinge joint, or an electromagnetic slide, or another positioning mechanism may be used to adjust a tool or the stage the tool is on in reaction to its detected position and its intended position. 
     By way of example, the systems and methods described herein can be used with drills, nail guns, and other tools that operate at a fixed position. In such embodiments, the tool and software could be modified such that the plan includes one or more target points instead of a full design. The device could be moved by the user such that a target position is within the adjustment range. The software could then move the tool to the correct target position. The user could then use the tool to drill a hole, drive in a nail, or perform other operations. 
     In some embodiments, the tools can facilitate performing a task without providing automatic adjustment. For example, the stage, pivot, motors, and eccentrics could be removed. The tool could be attached to the lower stage housing. The software could be modified such that the plan includes one or more target points. The user could move the device such that the tool is directly over the target position. The user could use the location feedback provided on the display to perform accurate positioning. 
     In some embodiments, the present disclosure facilitates guiding or positioning a jigsaw. A jigsaw blade may be rotated and moved in the direction of the blade, but not moved perpendicular to the blade or it will snap. The present disclosure may include a rotating stage that can be placed on top of the positioning stage. The jigsaw may be attached to this rotating stage. The software may be modified to make the jigsaw follow the plan and rotate to the correct orientation, and made to ensure that the jigsaw was not moved perpendicular to the blade. In some embodiments, a saber saw may take the place of the jigsaw to achieve the same effect. The cutting implement may be steered by rotating the rotating stage, and the cutting implement could be moved along the direction of cutting by moving the positioning stage. 
     In some embodiments, the system may support rotation and not support translation. For example, the system may automatically orient the blade in a scrolling jigsaw (e.g., a jigsaw with a blade that can be rotated independently of the body). In this embodiment, the software may steer the blade to aim it at the correct course and the user may be responsible for controlling its position. 
     In some embodiments, the system may position a scroll saw. For example, the camera may be coupled to the scroll saw, and the user may move the material. The upper and lower arms of the scroll saw may be mechanized such that they can move independently by computer control. The user may then move the material such that the plan lay within the adjustment range of the scroll saw, and the software would adjust the scroll saw to follow the plan. In some embodiments, the upper and lower arms could be moved to the same position, or moved independently to make cuts that are not perpendicular to the material. 
     In some embodiments, the position correcting device can be mounted to a mobile platform. For example, the device may be placed on material and left to drive itself around. The device can also be used in an alternative embodiment in which two mobile platforms stretch a cutting blade or wire between them. For example, each platform may be controlled independently, allowing the cutting line to be moved arbitrarily in 3D, for example to cut foam. 
     In some embodiments, the system may be coupled or otherwise attached to vehicles or working equipment such as a dozer in which the position-correcting mechanism is mounted on the vehicle. For example, some embodiments of the hybrid positioning system may include a vehicle comprising a first position-correcting system that is accurate to within a first range and a second position-correcting system that is accurate to a second range that is more precise than the first range. The vehicle may be driven over a sheet of material such as a steel plate lying on the ground, and a cutting tool such as a plasma cutter could be used to cut the material. In some embodiments, the present disclosure may facilitate a plotting device or painting device, for example to lay out lines on a football field or mark a construction site. The vehicle, for example, may include an industrial vehicle such as a forklift type vehicle configured to include a cutter or other tool, a camera, and control circuitry described herein to determine location of the vehicle (or the tool) on the material, identify where to cut or mark the material, and adjust the tool to cur or mark the material in the appropriate location. 
       FIG.  6    is a block diagram of a computer system  600  in accordance with an illustrative implementation. The computer system  600  can be used to implement system  680 . The computing system  600  includes a bus  605  or other communication component for communicating information and a processor  610  or processing circuit coupled to the bus  605  for processing information. The computing system  600  can also include one or more processors  610  or processing circuits coupled to the bus for processing information. The computing system  600  also includes main memory  615 , such as a random access memory (RAM) or other dynamic storage device, coupled to the bus  605  for storing information, and instructions to be executed by the processor  610 . Main memory  615  can also be used for storing position information, temporary variables, or other intermediate information during execution of instructions by the processor  610 . The computing system  600  may further include a read only memory (ROM)  1220  or other static storage device coupled to the bus  605  for storing static information and instructions for the processor  610 . A storage device  625 , such as a solid state device, magnetic disk or optical disk, is coupled to the bus  605  for persistently storing information and instructions. 
     The computing system  600  may be coupled via the bus  605  to a display  635 , such as a liquid crystal display, or active matrix display, for displaying information to a user. An input device  630 , such as a keyboard including alphanumeric and other keys, may be coupled to the bus  605  for communicating information and command selections to the processor  610 . In another implementation, the input device  630  has a touch screen display  635 . The input device  630  can include a cursor control, such as a mouse, a trackball, or cursor direction keys, for communicating direction information and command selections to the processor  610  and for controlling cursor movement on the display  635 . 
     According to various implementations, the processes described herein can be implemented by the computing system  600  in response to the processor  610  executing an arrangement of instructions contained in main memory  615 . Such instructions can be read into main memory  615  from another computer-readable medium, such as the storage device  625 . Execution of the arrangement of instructions contained in main memory  615  causes the computing system  600  to perform the illustrative processes described herein. One or more processors in a multi-processing arrangement may also be employed to execute the instructions contained in main memory  615 . In alternative implementations, hard-wired circuitry may be used in place of or in combination with software instructions to effect illustrative implementations. Thus, implementations are not limited to any specific combination of hardware circuitry and software. 
     Although an example computing system has been described in  FIG.  6   , implementations of the subject matter and the functional operations described in this specification can be implemented in other types of digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. 
     Implementations of the subject matter and the operations described in this specification can be implemented in digital electronic circuitry, or in computer software, firmware, or hardware, including the structures disclosed in this specification and their structural equivalents, or in combinations of one or more of them. The subject matter described in this specification can be implemented as one or more computer programs, i.e., one or more circuits of computer program instructions, encoded on one or more computer storage media for execution by, or to control the operation of, data processing apparatus. Alternatively or in addition, the program instructions can be encoded on an artificially generated propagated signal, e.g., a machine-generated electrical, optical, or electromagnetic signal that is generated to encode information for transmission to suitable receiver apparatus for execution by a data processing apparatus. A computer storage medium can be, or be included in, a computer-readable storage device, a computer-readable storage substrate, a random or serial access memory array or device, or a combination of one or more of them. Moreover, while a computer storage medium is not a propagated signal, a computer storage medium can be a source or destination of computer program instructions encoded in an artificially generated propagated signal. The computer storage medium can also be, or be included in, one or more separate components or media (e.g., multiple CDs, disks, or other storage devices). Accordingly, the computer storage medium is both tangible and non-transitory. 
     The operations described in this specification can be performed by a data processing apparatus on data stored on one or more computer-readable storage devices or received from other sources. 
     The term “data processing apparatus” or “computing device” encompasses various apparatuses, devices, and machines for processing data, including by way of example a programmable processor, a computer, a system on a chip, or multiple ones, or combinations of the foregoing. The apparatus can include special purpose logic circuitry, e.g., an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit). The apparatus can also include, in addition to hardware, code that creates an execution environment for the computer program in question, e.g., code that constitutes processor firmware, a protocol stack, a database management system, an operating system, a cross-platform runtime environment, a virtual machine, or a combination of one or more of them. The apparatus and execution environment can realize various different computing model infrastructures, such as web services, distributed computing and grid computing infrastructures. 
     A computer program (also known as a program, software, software application, script, or code) can be written in any form of programming language, including compiled or interpreted languages, declarative or procedural languages, and it can be deployed in any form, including as a stand alone program or as a circuit, component, subroutine, object, or other unit suitable for use in a computing environment. A computer program may, but need not, correspond to a file in a file system. A program can be stored in a portion of a file that holds other programs or data (e.g., one or more scripts stored in a markup language document), in a single file dedicated to the program in question, or in multiple coordinated files (e.g., files that store one or more circuits, sub programs, or portions of code). A computer program can be deployed to be executed on one computer or on multiple computers that are located at one site or distributed across multiple sites and interconnected by a communication network. 
     Processors suitable for the execution of a computer program include, by way of example, both general and special purpose microprocessors, and any one or more processors of any kind of digital computer. Generally, a processor will receive instructions and data from a read only memory or a random access memory or both. The essential elements of a computer are a processor for performing actions in accordance with instructions and one or more memory devices for storing instructions and data. Generally, a computer will also include, or be operatively coupled to receive data from or transfer data to, or both, one or more mass storage devices for storing data, e.g., magnetic, magneto optical disks, or optical disks. However, a computer need not have such devices. Moreover, a computer can be embedded in another device, e.g., a mobile telephone, a personal digital assistant (PDA), a mobile audio or video player, a game console, a Global Positioning System (GPS) receiver, or a portable storage device (e.g., a universal serial bus (USB) flash drive), to name just a few. Devices suitable for storing computer program instructions and data include all forms of non volatile memory, media and memory devices, including by way of example semiconductor memory devices, e.g., EPROM, EEPROM, and flash memory devices; magnetic disks, internal hard disks or removable disks; magneto optical disks; and CD ROM and DVD-ROM disks. The processor and the memory can be supplemented by, or incorporated in, special purpose logic circuitry. 
     To provide for interaction with a user, implementations of the subject matter described in this specification can be implemented on a computer having a display device, e.g., a CRT (cathode ray tube) or LCD (liquid crystal display) monitor, for displaying information to the user and a keyboard and a pointing device, e.g., a mouse or a trackball, by which the user can provide input to the computer. Other kinds of devices can be used to provide for interaction with a user as well; for example, feedback provided to the user can be any form of sensory feedback, e.g., visual feedback, auditory feedback, or tactile feedback; and input from the user can be received in any form, including acoustic, speech, or tactile input. 
     Referring to  FIG.  7 A , an illustrative example of an embodiment of a design plan and marking material  702  is shown. Placing marking material  704  may facilitate mapping the target material. For example, the target material may not contain sufficient differentiating marks. Adding differentiating marks (e.g., stickers, ink, pencil) to the target material may facilitate the system  680  in mapping the target material and tracking the positioning of the cutting tool during the cutting process. In this example, the design plan is in the shape of a country. The marking material may be placed on the surface of the target material to facilitate mapping the target material and tracking the position and adjusting the position in accordance with the design. 
     Referring to  FIG.  7 B , an illustrative example of an embodiment of locating markers  706  is shown. The locating markers  706  may be included as part of the design plan or may refer to a type of marking material  702  used to form the design plan. The locating markers  706  may be placed on the target material and used by the system  680  to map the target material and track a position of the cutting tool relative to the surface of the material. 
     Locating markers  706  can be designed, constructed or configured such that they are easy for the system  680  to detect and read (e.g., via camera or sensor  682 ). For example, the locating markers  706  may include dominoes that represent a binarized image. A binarized image may include an image with two values, such as an image with two colors. In some embodiments, the two colors may be selected such a first color of the two colors contrast with a second color of the two colors. For example, the two colors may include white and black, red and white, orange and blue, green and purple, etc. Dominoes-based locating markers  706  may be easy and fast to read by system  680 . By using locating markers  706  with a predetermined number of features (e.g., blobs  710 ), the locating markers  706  can be read from a binarized image contour tree fast. Further, each domino can include a number, which facilitates tracking multiple dominoes. Further, the system  680  can easily determine a subpixel accuracy for each circle  710 . In some embodiments, corner circles (e.g.,  710 ) may be present in each of the plurality of dominoes  706 . Having a corner circle  710  present in each of the dominoes facilitates reading the locating markers  706 , and may allow the system  680  to read the locating markers at increased distances because there is a uniform size of features. Having uniformed sized features prevents a subset of the features from disappearing from the binzrized image before all the features disappear. For example, if all the features  710  are the same size, then the system  680  may either detect all the features, or detect none of the features if the locating marker  708  is outside a detection range. 
     In some embodiments, the locating markers  706  can include a fiduciary marker  708 . A fiduciary marker may refer to a marker that can be detected by system  680  with minimal computation power. In some embodiments, the system  680  can detect the locating markers  700  directly from input that is a black-and-white image (possibly as a binarization of an image with more data, e.g. grayscale or full color). 
     In some embodiments, the system  680  can detect locating markers  706  using a contour tree of a binarized image. The contour tree may refer to a tree of blobs. A blob may refer to a region of the same color. The contour may refer to or include a border of the blob or the region of the same color. The blob may have a shape, such as a circle, square, triangle, polygon, oval, ellipse, rectangle, pentagon, outline, or another shape that allows the system  680  to detect a location marker. 
     In some embodiments, the blobs can be organized in a tree such that each node in the tree corresponds to a blob. Further, a node may be a child of another node if the child blob is encompassed by the parent blob. For example, in an image of the capital letter “B”, there are four blobs: the white background, the black of the letter, and two white blobs of the inner parts of the B. They are organized in a tree such that the letter is the child of the background and the two inner blobs are both children of the letter. 
     In some embodiments, location markers may include dominoes as illustrated in  FIG.  7 B . While rectangle dominoes are illustrated in  FIG.  7 B , other markers with patterns or other shaped blobs can be used. For example, rather than a rectangle marker  708 , the marker may be a polygon, circle, ellipse, square, triangle, pentagon, etc. The blobs  710  may be circles, or other shapes. The collection or plurality of markers may be referred to as a scene  706  or plurality of markers  706  or plurality of candidate location markers  706 . A marker  708  may be a candidate marker because the system  680  may perform initial processing to identify the image and determine whether the image is a location marker based on a threshold test or satisfying a criteria (e.g., whether blobs are present in predetermined locations, is there a pattern present, or other signature that indicates that the image corresponds to a location marker  708 ). 
     The location markers may include one or more rows  712  including one or more markers  708 ; and one or more columns  714  including one or more markers  708 . In some embodiments, the plurality of location markers  706  or scene  706  may be symmetrical (e.g., a same number of rows and columns). In some embodiments, the plurality of location markers  706  or scene  706  may not be symmetrical (e.g., a different number of rows and columns). 
     Each of the dominoes  706  may include a recognizable signature in the contour tree. For example, a domino may include 10 white blobs inside a black blob. The white blobs may not have children blobs. The domino configuration may include a contour tree with ten white children that are leaves of the black background tree. Therefore, if the system  680  detects this configuration (e.g., a black blob with 10 white blobs), the system  680  can take the black blob and process it as a fiducial marker. This additional processing may end up rejecting the domino as a marker, or accepting the domino as a location marker. This possibility extends to any recognizable signature in the contour tree, which may involve a variable number of children blobs, as long as it is distinctive enough that just from the contours one can have a good probability that it is a marker and spend additional computational resources to study it closer. 
     Thus, the system  680  can be configured to perform an initial assessment of a detected image using an initial image processing technique. During the initial processing technique, the system  680  identifies a contour tree to determine if the contour tree matches or satisfies an initial screening. For example, if the system  680  detects a black blob and 10 white blobs (e.g., as shown in domino  708 ), the system  680  may determine that the image may include a location marker, and forward the image for further processing. By performing an initial assessment, the system  680  can prescreen images and select a subset of the images for further, more computationally intensive processing. Thus, the system  680  can increase efficiencies and reduce the amount computational resources used to determine the location of a tool relative to a working surface. 
     In some embodiments, the marker that can be detected extremely quickly by binarizing an input image, computing the contour/blob tree, or looking for a known signature. In some embodiments, the location marker may encode data into each fiducial (e.g.,  708 ) and be easy to detect. For example, the fiducial marker  708  may encode a number, which allows the system  680  to keep track of (manage, maintain, identify, or determine) multiple fiducials present in a scene (e.g., a scene may refer to location markers  706 ). The number of the fiducial  708  may be unique in the scene  706 , or may not be unique in the scene  706 . In some embodiments, marker such as each of the dominoes  708  includes a pattern of white blobs that encodes a number in binary. 
     In some embodiments, a marker  708  may include blobs (e.g.,  710 ) that are positioned in a predetermined location. A marker  708  may include blobs in each of the four corners, allowing the system  680  to determine not just the presence of the fiducial marker  708  but a layout for it (such as the position and orientation of a marker relative to the camera  682 . Including blobs in predetermined positions may improve the ability of system  680  to decode a message encoded in the marker itself. For example, if the blobs are arranged in a grid, recognizing the corners provides a layout of the grid and allows the system  680  to map each grid square to a 1 or 0 for a blob being present or absent. In some embodiments, the system  680  may use the blobs in the predetermined location of the marker to detect the layout of the domino or marker  708 , but then parse some encoded data in another way, which may or may not be encoded in the binarized image/contour tree. 
     In some embodiments, the marker  708  may include blobs that are shapes that can then be resolved with subpixel accuracy by referring back to the full-color (or grayscale) image. For example, the system  680  may identify the blobs as circles (or preconfigured to identify the blobs as circles). The system  680  can determine the bounding box of each blob in the binarized image. The system  680  can then use the corresponding grayscale pixels in the grayscale image to fit an ellipse (circle viewed in perspective) to the pixels, giving a subpixel accuracy. The system  680  may more accurately detect the position and orientation of the fiducial  708  relative to the camera by using this subpixel-accurate detections of the blobs. This position and orientation can then be fed forward in the system  680  for further processing, such as localization of the camera in 3D space. 
     Referring now to  FIGS.  8 A- 8 B , systems, methods, and apparatus for directing and extracting dust is shown. Dust extraction may refer to the evacuation of particles of material that have been removed from a bulk workpiece (surface of a material, work surface) during a machining process such as milling, routing, sanding, etc. In the domain of woodworking, the dust may be saw dust. Effectively extracting dust facilitates maintaining a clean working environment, safe air for breathing that is free of dust, and prevents a buildup of dust in the vicinity of the tool that can otherwise impede its cutting action and also result in the generation of excessive heat. Additionally the accumulation of wood dust can create an explosion risk. Further, for automatically guided tools (such as system  680 ) that utilize an optical method for localization (e.g., camera  682 ), dust can interfere with the tool&#39;s ability to determine a location of the tool relative to the surface of the material. Systems, methods and apparatus of the present disclosure efficiently evacuating dust from the working area of a tool. In some embodiments, dust can be routed away from the working area in a controlled direction in the absence of a vacuum source. 
       FIG.  8 A  illustrates a tool  800  configured to direct and evacuate dust in accordance with an embodiment. The tool  800  includes a rotating cutter  1  (or tool tip, or cutting member, or working member) that shears material  2  as the rotating cutter  1  moves axially, laterally, or a combination thereof through the material  2 . The tool  800  includes a tool frame  3 . The tool frame  3  may include a cavity formed of a void in the tool frame  3 . The cavity  3  may be further formed by a space  4  where portions of working material  2  have been removed or cut away. A cutting member or router bit or tip of the tool can extend through cavity  3 . The cavity  3  can form one or more channels or a portion of a channel. The channel directs air flow  6 . Channels are further illustrated in  FIGS.  9 A- 9 B . The tool can include a camera  10 , which can include one or more functionality of camera  682 . The camera  10  can include or be referred to as a sensor, such as an image sensor, infrared sensor, or laser sensor. 
     In some embodiments, the rotational motive power for the rotating cutter  1  may be generated by a router  5  or spindle  5  (e.g., a woodworking trim router, or metal cutting tool, or plastic cutting tool, etc.) that includes an integral fan  802 . The fan  802  may be a separate fan that is integrated into the spindle  5 , or the fan  802  may refer to an airflow that is generated as a by-product of the spindle  5  rotating the cutting tool  1 . In some embodiments, the fan  802  may be external to the tool, such as external to the spindle  5 . The fan  802  can include one or more vanes or blades in an arrangement that, when rotated, generates airflow. This fan  802  can generate a downward airflow  6  that drives dust out of the collection cavity formed by the tool frame  3  and space  4  and along channels in the tool&#39;s base plate  7 . These channels direct dust towards the front of the tool  8 , which keeps dust from accumulating to the rear of the tool  9  where an optical locating system  10  (e.g., camera  682 ) may be aimed. In some embodiments, the front  8  of the tool  800  may refer to a portion of the tool that faces away from the direction the tool is cutting or a portion of the tool closer to the user of the tool. In some embodiments, the rear  9  of the tool  800  may refer to a portion of the tool that faces the direction the tool is cutting or a portion of the tool further away from the user of the tool. In some embodiments, the rear  9  of the tool refers to the portion of the tool  800  where a camera  10  is aimed. The tool  800  can include a vacuum port  11  that opens into one of the channels formed by voids  3  and  4  that receives air flow  6 . 
       FIG.  8 B  illustrates an embodiment of a tool  801  similar to tool  800  that includes a vacuum source  12  attached to the vacuum port  11 . The vacuum source  12  biases airflow towards the vacuum source  13 . This can extract through the connected channel formed by voids  3  and  4  in base plate  7  and into the vacuum source  12 . In this configuration, dust may be efficiently removed from the tool without entering the surrounding environment (e.g., rear of tool  9 ). 
     The channel formed by cavities  3  and  4  allow the airflow  6  generated by the fan  802  of the tool spindle  5  and the airflow generated by the vacuum source  12  to act along a common path to remove dust. This provides for efficient dust extraction system as the vacuum source  12  is not fighting against the airflow generated by the integrated spindle fan  802 . 
       FIG.  9 A  illustrates a top-down perspective view of an apparatus  900  for directing and extracting dust. The apparatus  900  may be coupled to, be part of, or be formed of one or more component of systems or apparatus  800  or  801 . In some embodiments, apparatus  900  includes the base plate  7  of the tool  800 . The baseplate  7  includes channels  904   a - b  formed by the void or cavity  3  in the base plate  7 . A portion of the base plate  7  faces or rests on or is opposite the material  2 . The fan  802  generates air flow  6  that flows downward towards the material  2 . The vacuum source  12  generates airflow  13  towards the vacuum source  12  and vacuum port  11 . The direction of airflow  6  as going towards the material  2  is illustrated by an X, while the airflow  13  shown going towards the vacuum port  11  is illustrated by a dot in a circle. 
     In some embodiments, the channels  904   a - b  formed in base plate  7  are V-shaped. In some embodiments, there may be two channels  904   a  and  904   b  that extend from the cavity  3 . In some embodiments, there may be one channel (e.g., just channel  904   a ). In some embodiments, there may be a plurality of channels (e.g., two or more channels). One of the plurality of channels may include a vacuum port  11  coupled to a vacuum source  12 . The channels  904   a  and  904   b  may form a U shape. The channels  804  may include a third channel that extends perpendicular to channels  904   a  and  904   b  via the cavity  3 . 
     The channels  904   a  and  904   b  may form an angle  906 . The angle  806  may range from 1 degree to 180 degrees. In some embodiments, the angle  906  may be 90 degrees, 45 degrees, 60 degrees, 120 degrees, etc. The angle  906  may be selected such that dust from material  2  is effectively directed away from the rear  9  of the tool and towards the front  8  of the tool via channel  904   a - b  and air flow  6  and  13 . 
     The channels  904   a - b  may include a channel depth. The channel depth may be the same for channel  904   a  and channel  904   b,  or may be different among the different channels. The channel depth may be greater than zero. The channel depth may be a value that ranges from 0.02 inches to 2 inches. The depth may be less or greater based on the type of tool or type of material being cut. For example, a size of particles being directed or extracted may determine a channel depth (e.g., shallower channel depth for smaller particles, and deeper channels for bigger particles). 
     In some embodiments, a first component of the air flow  6  and  13  generated from fan  802  may be greater than a second component of the air flow  6  and  13  generated from vacuum source  12 . In some embodiments, a first component of the air flow  6  and  13  generated from fan  802  may be less than or equal to a second component of the air flow  6  and  13  generated from vacuum source  12 . 
     In some embodiments, the air flow generated from vacuum source  12  may be determined such that the air flow holds the tool  800  (or apparatus  900 ) to the material  2 . This may increase the friction between the portion of the tool touching the material, which may increase stability while cutting or performing the task on the material  2 . 
       FIG.  9 B  illustrates an apparatus  902  for directing or extracting dust away from a rear  9  of a tool.  FIG.  9 B  illustrates a top-down perspective view of the apparatus  902  or base plate  7  including channels  904   a - b . The apparatus  902  may be similar to or include one or more component of apparatus  900 . In some embodiments, the apparatus  902  includes a vacuum port  11 , but is not coupled to a vacuum source (e.g., as shown in apparatus  900 ). While the apparatus  902  may not be coupled to a vacuum source at vacuum port  11 , the apparatus  902  may still direct and extract dust via channels  804  and air flow  6  generated by a fan (e.g., fan  802 ). 
     The vacuum port  11  may be positioned anywhere along channel  904   a  or channel  904   b.  In some embodiments, the vacuum port  11  may be positioned closer to an edge or corner of the base plate  900  relative to the cavity  3 . The distance  908  between the vacuum port  11  and edge of the base plate  902  may be greater than zero. The distance  910  between the vacuum port  11  and the cavity  3  may be greater than zero. The distance  910  may be different from distance  908 . The distance  910  may be greater than distance  908 . The distance  910  may be a multiple of the distance of  908 . The distances  908  and  910  may be determined such that dust can be effectively and efficiently directed and extracted away from rear  9  of tool. 
       FIG.  9 C  illustrates a bottom perspective view of base plate  910 . Base plate  910  may correspond to base plate  7 . Base plate  910  includes channels  912   a - b,  which may correspond to channels  904   a - b.  The base plate  910  includes a cavity  916  that may correspond to cavity  3 . The base plate  910  includes a vacuum port  914  in channel  912 , which may correspond to vacuum port  11 . The vacuum port  914  may or may not be connected to a vacuum source. 
     The base plate  910  can be made of any material that facilitates operation of the system  680  or tool  800 . The material may be metal, plastic, an alloy, or other material that provides adequate structural support for the tool  800  and friction to allow the tool to glide on the surface while providing some stability. 
       FIG.  9 D  is a top down perspective view of base plate  920 , which may correspond to an embodiment of the base plate  902  of  FIG.  9 B . The base plate  920  includes a cavity  922  through which the cutting member or tip of the tool may extend. The base plate  920  may include a vacuum port  924 . 
     The base plate  920  may include channels on the bottom of the base plate  920  (e.g., the portion or side of the base plate opposite the material on which a task is to be performed). The base plate  920  may include additional openings or cavities or grooves for one or more screws, or coupling mechanisms used to couple the base plate  920  to a tool, such as tool  800 . 
     Referring to  FIG.  10 A , a system, method and apparatus for determining a position of a tool tip relative to a work surface or material is shown. The system, method and apparatus can calibrate position detection for the tool. In some embodiments, system  680  can be configured, designed or constructed to determine the position of the tool tip relative to the work surface. The system  1000  (or tool  1000 ) can move, position, or control motion of a tool tip  24  in one or more directions (e.g.,  FIG.  10 B  shows the tool tip  24  touching the surface of the material  2 ). The control may be manually or automatically motivated. In some embodiments, the tool  1000  may include or be configured with automatic control of the height of a rotating cutter  24  relative to the surface of a workpiece or material  2 . The system  1000  can include one or more function or component of the system or apparatus of  FIGS.  1 - 9  and  11 A- 11 B . 
     The system  1000  (or tool  1000 ) can calibrate position detection for the tool. The system  1000  can include a base  18  coupled to the tool  1000 . The base  18  can be in contact with a working surface  2 . In some cases, the base  18  can include a pad  22 . For example, the base  18  can include a pad  22  such that the base  18  is in contact with the working surface  2  via the pad  22 . Thus, and in some embodiments, the base  18  can refer to the base  18  and the pad  22 . In some embodiments, the base  18  may not be in contact with the working surface. The base  18  can be in contact with the sensors  23  that are in contact with the pad  22 , and the pad  22  can be in contact with the working surface or workpiece or material  2 . 
     The system  1000  can include one or more computing device having one or more processors. In some cases, the system  1000  can include the one or more computing devices remote from the tool. For example, the tool can include a wireless or wired communication interface that can transmit and receive data or control information from one or more computing devices that are remote from the tool. 
     The system  1000  can include one or more sensors  23  communicatively coupled to the computing device. The system  1000  can include a motor  19  controlled by the computing device to extend and retract the tool tip  24  towards and away from working surface  2 . The motor  19  can control or include or refer to one or more components of the system  1000  configured to extend or retract the tool tip  24 , including, for example, a moveable carriage  15 . 
     The system  1000  can identify, via the one or more sensors  23 , a first value of a parameter indicative of an amount of force exerted by a portion of the base on the working surface. For example, the sensor  23  can include a force sensor  23 . The system  1000  can determine the first value as a first force value that indicates a default or initial force exerted by the base  23  on the material  2 . This may indicate a weight of the tool. The force can be measured or determined in Newtons or pounds. The sensor  23  can repeatedly detect or measure the value of the parameter based on a time interval (e.g., every 0.1 second, 0.5 second, 1 second, 2 seconds, 3 seconds, 5 seconds, or some other time interval). The sensor  23  can compare a first value or first measurement with a second or subsequent measurement. The sensor  23  can repeatedly compare a measurement with a subsequent measurement until the sensor detects a change or difference (e.g., by 0.5%, 1%, 2%, 3%, or an absolute change such as 1 N, 0.5 N, 0.25 N, 0.1N, 0.05N, or 2N) between measurements. The difference can refer to a difference by a predetermined threshold. The threshold can be fixed or dynamic. The threshold can be based on a resolution of the sensor  23 . 
     The system  1000  can instruct the motor  19  to instruct the motor to extend the working member or tip  24  towards the working surface  2 . The system  1000  can then identify, via the sensor  23  upon the working member  24  contacting the working surface  2 , a second value of the parameter. This second value can be a second force value. The second force value can be less than the first force value determined by the sensor  23  when the tool tip  24  was not in contact with the working surface. In some cases, there may be multiple sensors  23  and each sensor can determine a first force value and a second force value. In some cases, a first sensor can determine a first force value that is different from a first force value detected by a second sensor. The first values can refer to when the tool tip is not in contact with the material  2 . The first and second sensors may identify different first values because due to the center of gravity of the tool not located evenly in between the first and second sensors. Thus, when the tool tip  24  contacts the material  2 , a second force value detected by the first sensor may be different from a second force value detected by the second sensor. For example, when the tool tip  24  contacts the material  2 , the base  18  of the tool may tilt in an angle (e.g., 1 degree, 2 degree, 5 degree, or 10 degrees). The tilting of the base  18  may cause the first sensor  22  to measure a second force value that is less than the first force value measured by the first sensor  22 , while the second sensor  22  can measure a second force value that is greater than the first force value measured by the second sensor. 
     The system  1000  (or computing device) can identify the first value of the parameter based on a portion of the base  18  of the tool in contact with the working surface  2 . The system  1000  can identify, via the sensor  23 , the second value of the parameter based on the portion of the base of the tool not in contact (e.g., partially in contact or exerting less force on the surface than previously being exerted) with the working surface responsive to the motor  19  causing the working member  24  to contact the working surface  2 . For example, not in contact may refer to or include less force being exerted by the portion of the base  18 . In some cases, the system  1000  can instruct the motor  19  to contact the working surface  2  to tilt at least a portion the base  18 . Tilting the base  18  can refer to distributing the force exerted by the base  18  such that a first portion of the base  18  exerts greater force on the material  2  than a second portion of the base  18 . Tilting the base  18  can refer to changing the distribution of force exerted by the portions of the base  18 . The system  100  can determine the z-axis position of the working member  24  relative to the working surface  2  responsive to the working member  24  tilting the base  18  of the tool responsive to the working member  24  contacting the working surface  2 . 
     The system  1000  can compare the first value of the parameter with the second value of the parameter to generate a difference between the first value and the second value. The system  1000  can determine an absolute difference (e.g., a difference of an amount of force), or simply determine that there is a difference in that the two values are not equal to each other. The system  1000  can determine that if the first and second values for a particular sensor  22  are not equal, then it is due to the tool tip  24  contacting the material  24  and offset or distributing the force exerted by the base  18  onto the material  2 . The system  1000  can determine the z-axis position responsive to the first force value being greater than the second force value because less force may be exerted by the base  18  onto the material  2 . 
     Responsive to detecting this difference, the system  1000  can determine that the tool tip  24  has contacted the material, and use this information to determine a z-axis position of the working member relative to the working surface. For example, the system  1000  can determine that this is the baseline or default position for the tool tip  24 . The system  1000  can calibrate the position of the tool tip  24  such that this is a zero position. As the system  1000  retracts the tool tip  24  away from the material, the system  1000  can monitor or track the distance of the tool tip  24  from the calibrated zero position corresponding to the surface of the material  2 . For example, the system  1000  can control or instruct the motor  19  to retract or move the tool tip  24  a distance (e.g., 1 millimeter, 5 millimeters, 1 centimeters, 5 centimeters, or 10 centimeters) away from the calibrated zero position which may correspond to the surface of the material. The system  1000  can, in some cases, instruct or control the motor  19  to insert the tool tip  24  a distance into the material  2 . For example, the system  1000  can instruct or control the motor  19  to insert the tool tip  24  one centimeter beyond the calibrated zero position, which may insert the tool tip  24  one centimeter into the material  2 . For example, the system  1000  can make a one centimeter hole in the material using the calibrated zero position. 
     The system  1000  can instruct the motor  19  to retract the working member  24  in contact with the working surface  2  away from the working surface  2 . The system  1000  (or sensor  23  thereof) can identify when the working member  24  is not in contact with the working surface by measuring a third value of the parameter. The third value of the parameter may be greater than the second value of the parameter because the tool tip  24  is no longer offsetting the force exerted by the base  18  onto the material  2  (e.g., via sensor  23  or pad  22 ). The third value of the parameter may be equal to (e.g., substantially equal within 1%, 2%, 5%, or 10%) the first value of the parameter when the tool tip  24  was also not in contact with the material  2 . The system  1000  can determine a second z-axis position of the working member relative to the working surface responsive to a second difference between the first value and the third value less than a threshold (e.g., the difference is less than a percentage of the first value or the third value such as 1%, 2%, 3%, 5%, or 10%; or a force value such as 1 Newton, 0.5 Newton&#39;s, 0.01 Newton&#39;s, 2 Newton&#39;s, 5 Newton&#39;s, or 10 Newton&#39;s). 
     Thus, to facilitate controlling the height of the rotating cutter  24 , the tool may determine a reference or “zero” point so that the tool  1000  (e.g., via cutting member  24 ) can be positioned to remove an amount of material  2 . For example, the tool  1000  may plunge a rotating cutter  24  a specified depth into a workpiece  2  before being moved laterally to create a groove. The tool may use a method to precisely determine the position of the tool tip relative to the work surface. In some embodiments, the tool  1000  uses low cost sensors  23 , such as force sensors, that detect a delta or change in the force exerted by a portion of the tool  1000  on the material  2 . In some cases, the sensors  23  can include capacitive sensors, photo-electric sensors, electromagnetic sensors, load sensors, strain gauge load cells, piezoelectric crystals, hydraulic load cells, or pneumatic load cells. 
     As the tip  24  moves towards the material  2  and touches the material  2 , the force exerted by the base  18  may be reduced because the force is being offloaded to the tip of the tool  24 . Detecting this change in force may indicate that the tip of the tool is touching the surface of material  2  and allow the tool to configure or set or initialize this position as a zero position. This may be useful for handheld power tools including automatically guided tools, and may also be applied to fully automatic machine tools. 
     In some embodiments, the tool  1000  includes a router bit  1  mounted in the spindle  14  of a router  5  (e.g., woodworking trim router). The router  5  may be secured in a movable carriage  15  that slides on a guide rail  16 . The guide rail  16  may be mounted to a structural column  17 . The structural column  17  may be fixed to a base  18  of the tool  1000 . A motor  19  may be fixed to the base  18  of the tool  1000  to rotate a leadscrew  20 . The leadscrew  20  may pass through a nut  21  on the movable carriage  15 . The leadscrew  20  may include square threads, acme threads, or buttress threads. When the motor  19  rotates, the movable carriage  15  translates in proportion to the pitch of the leadscrew  20 . 
     In some embodiments, the movable carriage  15  may be mounted to a moving stage which is constrained in the Z direction by the frame. In some embodiments, the Z column or guide rail  16  may be mounted to a moving XY stage which is constrained in the Z direction by a frame of the device  1000 . For example, the tool or device  1000  can include a rig or frame with a stage that may be positioned on the surface of a piece of material such as wood. The tool can be electrically or mechanically coupled to the frame, and the frame together with the tool can be passed over the material. The tool can move (or provide instructions for a user to move) the frame, stage, or tool to a desired XY or Z coordinate on the material. For example, the tool may include one or more components (e.g., rig, tool, stage, etc.) of the system described in U.S. Patent Application Publication No. 2015/0094836. The U.S. Patent Application Publication No. 2015/0094836 is hereby incorporated by reference herein in its entirety. 
     In some embodiments, the tool  1000  may use one or more other configurations or techniques to move the tip  24  of a tool  1000  relative to the work surface. Other configurations may include a power screw, translation screw, ball screws, roller screws, fluid power, tear trains, worm drives, rack-and-pinion drives, electromagnetic actuation, piezoelectric actuation, hydraulic lifts, electrical lifts, rotary lift, pneumatic lift, mechanic lifts, levers, gears, etc. 
     The base  18  of the tool (or device)  1000  may be separated from the work surface  2  by a pad  22  on which the device  1000  rests. In some embodiments, one or more force sensors  23  may be positioned between the pad  22  and the base  18  of the device  1000 . The gravitational force generated by the weight of the device  1000  partially or fully passes through the one or more force sensors  23  when the device  1000  is resting on the work surface  2 . 
     To locate the tip  24  of the cutting tool  1000 , the system or device  1000  may move the carriage  15  closer to the work surface  2 , which moves the tip  24  towards the work surface. As this motion is performed, the force passing through the force sensors  23  may be measured (e.g., measured responsive to a motion, measured periodically, measured based on a time interval such as every millisecond, 10 milliseconds, 1 second, etc.). Once the tip  24  of the cutting tool makes contact with the work surface  2 , additional motion results in a fraction of the weight of the device  1000  to be transferred to the work surface  2  through the tool tip  24 , and the force passing through the sensors  23  is correspondingly reduced. The system detects the change in force on the one or more sensors  23  and the motion of the carriage may be stopped. The position of the carriage  15  is recorded and may correspond to the point at which the tool tip is positioned at the surface of the work. Because the tool tip and the work surface may be stiff, a detectable transfer of weight occurs over very small distances and the error of this method may correspond to less than 0.0005″ using a ¼″ carbide routing bit on a birch plywood surface. 
     The system  1000  can repeatedly extend and retract the tool tip  24  towards and aware from the material  2  or a surface (e.g., desk, bench, floor, or other support structure) supporting the material  2 . The system  1000  can repeatedly extend and retract the tool tip  24  to generate or create a 3-dimensional map of the material  2 . 
     In some cases, the system  1000  can extend the tool tip  24  adjacent to an edge of the material  2 . The system  1000  can extend the tool tip  24  adjacent to the edge of the material  2  until the tool tip  24  contacts a surface supporting the material  2 . The system  1000  can determine a thickness of the material by determining the distance beyond the surface of material  2  the tool tip  24  extends in order to contact the surface supporting the material  2 . The system can determining these positions using the force sensors  23  to detect when the tool tip  24  contacts the material  2  or the surface supporting the material. For example, the system  1000  (or motor  19 ) can extend the working member  24  towards a surface supporting the working surface. A part of the base  18  of the tool can be in contact with the working surface  2 , while a part of the base  18  of the tool may be off the material  2 . Or, in some cases, the base  18  may be in contact with the material  2 , and the material can be shaped or configured such that the tool tip  24  when extended may contact the surface supporting the material  2  as opposed to the surface; or the tool tip  24  may extend through a hole in the material  2  to contact the surface supporting the material  2 . The system  1000  (e.g., via sensor  23 ) can detect the working member  24  contacting the surface supporting the working surface. For example, the system  1000  can detect a third value of the parameter (e.g., force), and determine a thickness of the working surface  2  responsive to a second difference between the first value and the third value greater than a threshold (e.g., the difference can be greater than 1%, 2%, 5%, 10%, of one of the first value or third value; or the difference can be greater than a force value such as 1 Newton, 0.5 Newton&#39;s, 0.01 Newton&#39;s, 2 Newton&#39;s, 5 Newton&#39;s, or 10 Newton&#39;s). 
     The system  1000  can determine multiple location points based on the working member  24  of the tool contacting the working surface. For example, the system  1000  can repeatedly extend and retract the working member of the  24  to contact the material  2  and move the working member  24  away from the surface. The system  1000  can record information each time the tool tip  24  contacts the material  2  (or does not contact the material  2 ). For example, the system  100  can record or identify location points. Each location point can have an x-axis coordinate, a y-axis coordinate, and a z-axis coordinate. The x-y coordinates can be determined using markers on the surface of the material and may be relative to a surface of the material or position on the surface of the material. The x-y coordinates can be determined using fiducial markers on the surface of the material, imaging techniques, or visual techniques. For example, a second sensor of the tool (e.g., a visual sensor or camera) can determine the x-axis coordinate and the y-axis coordinate of each of the location points using a fiducial marker placed on the working surface. The system can determine the z-coordinate (or depth) by extending the tool tip  24  until the tip  24  contacts the surface, and measuring the depth relative to a calibrated zero position. The calibrated zero position can be a position on the surface of the material. The system  1000  can generate a three dimensional map of the working surface  2  using the location points. 
     The system  1000  can measure the geometry of the work surface  2  by correlating the tool tip  24  position with device (e.g., tool  1000 ) position on the plane of the work surface  2 . To do so, the tool tip  24  (e.g., a cylindrical tool with a conical or spherical tip) can first be related to the reference frame of the tool  100  by detecting the position of the tool tip  24 . Once the position of the tool tip  24  is known relative to the tool&#39;s reference frame, the tool can be positioned laterally over a surface of interest (e.g., working surface  2 ) to determine the vertical position of the working surface. The vertical position of the working surface can refer to a surface of the material of the working surface. In some cases, the vertical position can indicate a recess, cavity, indent, or concave portion in a piece of wood whose depth is of interest. In some cases, the vertical position can indicate a raised portion, bump, protrusion, or convex portion in a piece of wood whose depth is of interest. The tool tip can then be inserted, extended, lowered, plunged otherwise moved until the tool tip contacts the surface of the portion of the material (e.g., recess or protrusion). The additional displacement of the tool tip beyond the top portion of the surface where the tool tip first contacted the work surface can indicate the depth of the recess. Similarly, the reduction in displacement of the tool tip above the portion of the surface where the tool tip first contacted the work surface can indicate a height of the protrusion. If the surface profile of the recess was of interest, the tool might be moved around the recess to multiple points. The tool can determine, at each of the multiple points, the depth. The tool can record both the depth and lateral position of the tool (e.g., x, y, and z coordinates, where x and y coordinates can refer to the lateral position and the z coordinate can refer to the depth). The lateral motion could be accomplished automatically using a built-in positioning stage, or performed manually by the user, or a combination of both. 
     The system  1000  can identify or determine a center position of a hole on a work surface  2 . For example, a tool  1  with a conical tip  24  can be fitted into the system. The tool  1  can then be positioned approximately (e.g., within 5%, 10%, 15%, 20%, 25%, 30%, 50%, 75%, or 90% of the diameter of the hole) over the center of the hole, and plunged until the tip  24  contacts the circle of the hole. Because the tool tip  24  can be conical, the tool tip  24  can cause the tool to center over the hole. The tool can then determine the lateral position (e.g., x and y coordinates) using, for example, a vision system with a camera  10  to ascertain the position of the hole. 
     The system  1000  can include or communicate with a computing device, processor or microprocessor (such as a processor of system  680 ). The computing device can include the one or more process of system  680 . The system  1000  can use the computing device to control the motion of the positioning motor and also to measure the force passing through the one or more force sensors  23 . Sensors  23  may include, e.g., force-sensitive resistors, piezoelectric sensors, strain gages, load pins, shear beams, tension links, magnetic level gauge, torque sensor, load cells, hydraulic load cells, pneumatic load cells, elastic devices, magneto-elastic devices, plastic deformation, foil strain gauges, etc. 
     In some embodiments, the tool can detect the tilt using a camera, visual information, gyroscope, or 3-axis accelerometer. The tool can include a camera  10  (also illustrated in  FIG.  8 A ), or other sensor. Camera  10  can include one or more component or functionality of camera  682 . The camera  10  can determine a shift in a captured image corresponding to a tilt resulting from the base lifting. The camera  10  can take a first picture or image before the tool brings the tool tip  24  into contact with the working surface  2 , and then take a second image when the tool tip contacts the working surface. The camera  10  can repeatedly take images based on a time interval (e.g., every 1 second, 2 seconds, 3 seconds, 0.5 seconds, or 5 seconds) and compare a first image with a subsequent image to identify a tilt. The camera  10  can take a burst of images and then compare the images with one another to detect when the tool tip contacted the surface to cause the tilt. In some cases, each image in the burst of images can be associated with a time stamp. Each of the images can further be associated with, tagged with, or otherwise correspond to a position of the tool tip. The system can determine which image of the burst of images first indicates a tilt (e.g., an object in the image taken by camera  10  may appear closer when the tool  1000  is tilted towards the rear of the tool when the tool tip comes into contact with the material  2 ). In some cases, the system  1000  can determine a difference or misalignment in pixels between a first image and a subsequent image. Responsive to detecting the misalignment in the pixels, the system  1000  can determine that the tool tip contacted the material  2  at the timestamp corresponding to the subsequent or second image having the misaligned pixels relative to a first image or previous image. The camera can compare the first image with the second image to identify a tilt or variation between the two images. 
     The sensor  10  can include an image sensor or camera. The parameter can include a pixel. The pixel can have a location in the image. The system  1000  can capture (e.g., via the image sensor) a first image comprising a pixel with a first value (e.g., binary value, 256-bit value, red, green blue value, grayscale value, brightness value, or numerical value). The system  1000  can capture a second image comprising a second value of the pixel. The second value can be for the same pixel as the first value. The pixel can be a location in the image. The system  1000  can comparing the first image comprising the first value with the second image comprising the second value to identify the difference between the first value and the second value. The system can compare one or more pixels in the first image with one or more pixels in the second image to detect a difference. The system can compare the two captured images to determine that they are misaligned. The images may be misaligned due to the base being tilted in an angle, which may cause the camera to capture the second image at a different angle or from a different perspective as compared to the first image. Thus, the system can attribute the misalignment to the tool tip  24  contacting the surface of the working material and tilting the base. 
     The tool can determine the proximity of the tool tip  24  to the working surface  2  using a capacitive sensor  10  or an electromagnetic sensor  10 . For example, the electromagnetic sensor  10  can sense or detect a change in inductance of a sensing coil in proximity to the tool tip  24  or working member  24  that includes metal by sensing eddy currents induced in the metal. 
     In some cases, the tool  1000  can include an accelerometer. For example, sensor  23  or sensor  10  can include an accelerometer, such as a 3-axis accelerometer or gyroscope. The accelerometer can indicate the tilt responsive to a motion or sudden motion caused by the base lifting. For example, the accelerometer can determine a first value indicating the acceleration of the base of the tool when the tool tip is not in contact with the surface. The first value can be zero, for example, because the base may be resting on the working surface. The accelerometer can determine the second value when the tool tip touches or contacts the surface. The second value or second acceleration value can indicate an acceleration of the base, an impact, a movement, a force or other displacement of the base caused by the tool tip contacting the working surface and moving the base that is mechanically connected to the tool tip. The computing device can compare the first value with the second value to identify the acceleration of the base of the tool based on the working member contacting the working surface. In some cases, the computing device can determine that the first value and the second value are not equal or substantially equal (e.g., within 1%, 2%, or 5%), and determine the tool tip contacted the working surface based on there being a difference in acceleration. 
     The tool can determine or detect additional information about the tool including tip or working member position, diameter, or tool geometry. Determining the geometry of the tool can include or refer to determining the diameter of the cutting tool. The tool geometry information can be used to automatically determine a length of a cutting flute of the working member and an angle of the cutter (e.g. a V carving bit or helix angle). For example, the tool can include cameras  10  or a break-beam sensor  10  (e.g., laser break beam sensor, infrared break beam sensor, photoelectric sensor, or optical sensor) proximate to the tool tip  24 . The working member  24  can be dropped into the line of action of the sensors  10  and the tool can detect the position of the working member  24  when the working member  24  breaks the beam formed by sensors  10 . In some cases, the axis of the beam can be pre-calibrated relative to the coordinate frame of the tool. 
     In some cases, the system can include one or more vision cameras  10  aimed at the tool tip  24  or tool member  1  to determine the position of the working member  1  or tool tip  24 . The vision camera  10  can be pre-calibrated to the tool coordinate frame to detect the tool tip  24 . In some cases, the vision camera can include a linear charge coupled device (CCD) sensor or other image sensor. A linear CCD sensor may use less processing than a vision camera to detect the tool tip. 
     The system  1000  can measure the diameter of the working member  1  or tool tip  24 . The tool can shift the tool tip  24  around while measuring or determining the position of the tool tip. By shifting the tool tip, the tool can use a single break-beam sensor  10  to detect tool diameter by passing the tool left-to-right through the sensor  10 . The lateral motion of the tool can cause a first break and then un-obstruct the beam to provide a measure of the tool diameter. Since router bits can have helical flutes, the tool can perform multiple measurements along the length of the tool to determine the diameter. The tool can determine the diameter using eddy currents or capacitive sensing with a one-dimensional sensor to gather multi-dimensional information about the tool geometry by correlating the sensor data to the tool position. The tool can determine additional information about the tool tip  24  such as tip angle in the case of a v-cutting bit. Furthermore, the tool can include a vision camera  10  to detect geometric properties of the tool. 
     The system  1000  can include or be configured with a hybrid positioning system to position the working member of the tool. For example, the system can include a stage. The system can include a skid pad proximate to the stage to facilitate moving the stage. The system can include at least one motor adapted to move the stage. The system can included at least one motor controller that controls the at least one motor. The system can include a computing device or a processor in combination with one or more software applications for processing data and providing information to the at least one motor controller. The system can include a first sensor configured to capture first information of a surface of a material to build a map of the surface. The first information can include an image of the surface. The system can include a second sensor communicatively coupled with the processor. The second sensor can capture second information of the surface used to determine at least one of a location of the working member and an orientation of the working member relative to the surface. The computing device or processor can build the map of the surface using the first information captured by the first sensor. The computing device or processor can receive a design corresponding to the map of the surface built using the first information. The processor can display the design overlaid on the map via a display screen. The system can receive, via the second sensor, the second information of the surface. The system can determine, based on the second information of the surface and based on the map, at least one of the location of the working member and the orientation of the working member relative to the surface. The system can display the location of the working member overlaid on the map via the display screen. The system can determine, based on the design registered on the map and at least one of the location and the orientation, a desired location for the working member. The system can provide motor control information to control the at least one motor to move the stage and the working member to the desired location while the tool is advanced in a first direction that is within a selected range substantially adjacent to an outline of the design. The system can automatically realign the tool to a boundary edge of the design in a second direction as the tool is advanced in the first direction. 
     For example, the system  1000  can use the determined z-axis position of the working member to provide, based at least in part on the z-axis position of the working member, motor control information to control the one or more motors to move the working member from a first location to a second location. The motor control information can include one or more of x-axis information, y-axis information, or z-axis information. The tool can be advanced in a direction that is within a range adjacent to a predetermined path for the working member of the tool. 
     In some cases, the system  1000  can receive first information from the first sensor and determine, based on first information of the surface of the material, at least one of a first location (e.g., x-y coordinates, or x-y-z coordinates) of the working member of the tool and an orientation of the working member relative to the surface using a map of the surface. The system can indicate, via a display screen of the tool, the first location of the working member of the tool relative to the map of the surface. The system can retrieve a design corresponding to the map of the surface to identify a path for the working member of the tool. The system can compare the first location of the working member of the tool with the design to determine a second location for the working member of the tool corresponding to the path for the working member of the tool. The system can provide, based on at least one of the second location and the orientation, motor control information to control the at least one motor to move the stage and the working member to the second location. The tool can be advanced in a direction that is within a range adjacent to the path for the working member of the tool. 
     The system can perform a constant speed technique to provide the motor control information to control the at least one motor to move the stage and the working member to a plurality of subsequent locations while the tool is advanced in a corresponding plurality of subsequent directions. The system can automatically realign the tool to a boundary edge of the design in a third direction as the tool is advanced in a fourth direction. The system can display a target range window rendering an illustration of a point of reference of the tool, an intended cut path, and a desired tool movement path. The intended cut path can indicate a position in an x-y coordinates frame as well as z-axis depth. 
     The sensor can receive or capture a live feed of image data. The system can receive the live feed of image data captured by the sensor, and use the live feed image data to compare a previous position (e.g., x-y coordinates, or x-y-z coordinates) on the design and a preferred next position (e.g., x-y coordinates, or x-y-z coordinates) on the design to automatically realign a position of the tool. 
     While  FIGS.  10 A- 10 B  illustrate determining the position of a rotating cutting tool  24  relative to the work surface  2 , the method can apply to plotting pens, vinyl cutting knives, pipette tips, vacuum nozzles for pick and place machines, or any other system to determine a zero position position of a working member  24  relative to a working material  2 . 
       FIG.  10 C  illustrates a force sensor  23  adjacent to a pad in accordance with an embodiment. The force sensor  23  may be temporarily placed there to perform a calibration procedure to determine the zero position. The force sensor  23  may be removed after completion of the calibration procedure. 
       FIG.  10 D  illustrates a force sensor  23  positioned or placed on the top of the base plate  920 . The one or more force sensors  23  can be positioned anywhere on the tool  1000  such that the force sensor  23  can detect a change in force corresponding to the tool tip  24  touching the surface of the material  2 . The change in force may be a reduction in detected force because some of the force is being transferred via the tool tip  24  to the material rather than through the force sensor  23  onto the material. 
       FIGS.  11 A and  11 B  illustrate a tool  1100  with a base plate  1105 . The tool  1100  may include one or more component of the tool  1000 , and base plate  1105  may correspond to base plate  910 .  FIG.  11 A  illustrates the dust or particles that stay on the material when the dust extraction and direction techniques are not being used, while  FIG.  11 B  illustrates how the dust direction and extraction techniques described herein can remove the dust from the material (e.g., via airflow generated by a fan and/or vacuum source traveling through a channel away from the rear of the tool or extracted via a vacuum port). The tool  1100  can moving, via a cavity or channel of a base plate of the tool, particles of material removed from the working surface by the working member. The tool  1100  can evacuate, by a vacuum, the particles via the cavity away from the working member. 
       FIG.  12    illustrates a block diagram of a method of calibrating position detection of a tool, in accordance with an embodiment. In brief overview, the method  1200  includes a tool detecting a first value of a parameter at  1205 . At step  1210 , the tool extends a working member towards a working surface. At  1210 , the tool detects a second value of the parameter. At  1220 , the tool determines a position of the working member relative to the working surface. The method  1200  can be performed by one or more component or module of one or more system depicted in  FIGS.  1 - 11 B . 
     Still referring to  FIG.  12   , and in further detail, the tool detects a first value of a parameter at  1205 . The tool (e.g., via a sensor) can detect the first value of the parameter. The sensor can be communicatively coupled to a computing device comprising one or more processors. The parameter, or first value thereof, can indicate an amount of force exerted by a portion of a base of the tool on the working surface or towards the working surface. The tool can detect the first value of the parameter with the portion of the base of the tool in contact with the working surface. For example, the portion of the base can be resting or placed on the working surface or material. In some cases, the base can include a pad that is in contact with the working surface. 
     At step  1210 , the tool extends a working member towards a working surface. The tool (e.g., via a motor controlled by the computing device) can extend the working member towards the working surface. When the working member contacts the working surface, the base can be at least partially in contact with the working surface. For example, the working member can contact the working surface and at least partially lift or tilt a portion of the base. The portion of the base may or may not be in contact with the surface depending on how much the tool tip in contact with the surface of the material lifts or tilts the base. In some cases, the base may still be in contact with the surface, but the amount of force exerted by the base on the working surface may be less. This lesser amount of force may correspond to the second value of the parameter. 
     At  1210 , the tool detects a second value of the parameter. The tool (e.g., via the sensor) can detect when the working member contacts the working surface by identifying a second value of the parameter that is less than the first value of the parameter. The second value can be less than first value because the force exerted by the portion of the base can be less due to the tool tip distributing the force exerted by the base. The force can be distributed such that the tool tip exerts some of the force onto the material, or such that another portion of the base exerts greater force than a first portion of the base. For example, the tool tip can tilt the base such that a first portion of the base exerts less force than a second portion of the base. For example, the tool can detect the second value of the parameter with the portion of the base of the tool not in contact with the working surface responsive to the motor causing the working member to contact the working surface. The tool can determine the z-axis position of the working member relative to the working surface responsive to the working member tilting the base responsive to the working member contacting the working surface. 
     At  1220 , the tool determines a position of the working member relative to the working surface. The tool (e.g., via the computing device) can determine a z-axis position or depth of the working member relative to the working surface responsive to a difference between the first value and the second value greater than a threshold. The tool can calibrate the position detection system of the tool based on these detected z-axis position. For example, the tool can set this position as a zero, initial or default position. The system can then determine the z-axis coordinate or position of the tool tip relative to the calibrated zero position. In some cases, the tool may not calibrate the detected surface as a zero position, but may record the absolute distance of the spindle. As the tool tip length can vary based on the type of working member or tool, the position of the tip of the spindle can be predetermined by the tool as it may not be interchangeable. 
     The form and structure of embodiments of the present disclosure for use with a cutting tool are provided and depicted in  FIGS.  13 - 21   . The embodiments depicted in  FIGS.  13 - 21    provide a system or rig  100  which is configured for use with a router  500 . The system  100  includes two support legs  104  which are attached to a base housing  130  on the lower end and terminate into a device mount  122  at the upper end. The device mount  122  includes left and right display clips  124  to clamp or lock the monitor or smart device  570  into the device mount  122 . The device  570  includes a display screen  572  for the user to view the cutting path for that particular use. The base  130  also has left and right handles or grips  106  attached through handle support arms  108 . 
     The lower end of the base  130  has a bottom plate  139  which encloses the stage  150  and a lower stage skid pad  151 . The base  130  and bottom plate  139  are fastened to one another such as by machined screws. As seen in  FIG.  20   , the bottom plate  139  has a bottom skid pad  141  attached to the bottom. The bottom skid pad  141  is used to assist movement of the rig  100  along the surf tee of the material being worked on. The bottom skid pad  141  may be made of a high density polyethylene, Teflon, or other suitable material which is both durable and suited for sliding along the material. 
     The router  500  is added to the rig  100  by attaching the router base plate  510  to the stage  150 . As seen in  FIG.  21   , the stage  150  has several tool attachment points  164  for attaching the router base  510  to the stage  150 . The router base  510  has several router base support legs  508  which forms a cage around the router bit  512 . The router  500  also has a power cord  506  and an on-off switch  504 . The rig  100  may be implemented as a self-contained portable unit including an on-board source of power, such as a battery source. 
     The smart unit or monitor  570  can have an input cable  574  with a cable terminal or receptacle  576 . If the device is a smart unit the CPU, software, and memory will be on the device itself. If the device  570  is simply a monitor then the cable  574  and receptacle  576  will connect to the CPU unit. 
     As shown in  FIGS.  14 - 19   , the system  100  can contain a stage motor  210  and a pivot motor  220 . The stage motor  210  is used to control movement of the stage  150 . The pivot motor  220  is used to control movement of the pivot arm  156  which pulls or pushes the stage  150  to convert the rotational motion of the motors  210 ,  220  into a relatively linear motion. The stage motor  210  and pivot motor  220  each have their own motor cap  212 ,  222  respectively. 
     The motors  210 ,  220  can be controlled by the stage motor driver  253  and the pivot motor driver  254  which are connected to the printed circuit board  250  and the microcontroller board  252 . The microcontroller  252  processes low level instructions from the smart device or CPU unit (i.e. a laptop). The instructions would be instructions to move the motors  210 ,  220  to set positions (i.e. positions  150 ,  125 ) into the correct step commands to drive the motors to those positions. The motors&#39; orientations are tracked by homing them to a zero position once and then tracking all subsequent steps taken. Alternatively, the system could use rotary encoders to keep track of the state of the motor shafts&#39; orientations. The motors  210 ,  220  and the motor drivers  253 ,  254  are powered by connecting the power plug receptacle  255  into a power source. 
     As shown  FIGS.  15 - 16   , the back of the rig  100  includes a camera support  190 . The camera support  190  may be one or more support members which are connected to the upper stage housing  130  and terminate at the top of the rig  100  where a camera  300  is mounted. The camera  300  and a lens  304  are placed in a relatively downward position to capture images of the material being worked and the surrounding areas thereof. 
     The eccentrics can be used to convert the rotational motion of the motors into linear motion. Eccentrics are circular disks rotating around an off-center shaft. As the shafts are rotated, they produce linear motion in the collars wrapped around the eccentric disks. Eccentrics are able to maintain the same low backlash accuracy of a precision linear stage while being less expensive. A linear displacement range of ½″ is well within the capabilities of an eccentric. The tool can include two eccentrics mounted to the frame and connected to a stage that can slide on its base. The eccentrics can be rotated by stepper motors, and by rotating them the stage can be moved within the frame. The size and shape of the various eccentrics can be varied to provide larger or smaller relative movement of the tool  699  relative to the workspace. 
     To constrain the stage, one eccentric can be connected directly to the stage by a ball bearing coupling, while the other is connected by a coupling and a hinge. This linkage design results in a nonlinear relationship between eccentric orientation and stage position. Near the center of the range moderate rotation of an eccentric produces moderate motion of the stage. In contrast, near the edge of the range much larger rotations are necessary to move the stage a fixed amount. In the present invention, stage displacement is limited to approximately 95% of the maximum range to avoid positions with extreme nonlinearity. This linkage design also permits back driving, in that forces acting on the tool can cause the cams to rotate away from their target positions. However, the present invention makes use of adequately powered motors which have sufficient power to preclude back driving even in the presence of significant forces. 
     As shown in  FIG.  21   , the upper stage housing  130  can be a one piece unit with spacers  131 ,  133 ,  135  machined or formed into the upper stage housing  130 . The spacers  131 ,  133 ,  135  provide the required space for the stage  150  and pivot arm  156  to move. The front spacers  131 , side spacers  133 , and rear spacers  135  need not be formed as one unit. Instead, the front spacers  131 , side spacers  133 , and rear spacers  135  could be separate pieces attached to the upper stage housing  130 . The upper stage housing  130  also accommodates several upper stage skid pads  137 . The upper stage skid pads  137  allow the stage stabilizing arms  152  to move along the pads  137  with minimal friction. 
     The stage  150  is ideally made of a light but durable and strong material such as aluminum or some other alloy. The stage  150  is most likely machined to include one or more stabilizing arms  152 , the stage eccentric arm member  154 , tool attachment points  168 , and an opening  160  where the tool extends through the stage  150 . In addition, a pivot arm  156  is most likely machined from the same alloy or material as the stage  150 . 
     In operation the stage motor  210  moves in response to rotation of the stage motor shaft  184 . There is a stage eccentric cam member  174  attached to the stage motor shaft  184 . When the stage motor shaft  184  rotates the stage eccentric cam  174  rotates and the cam design causes the stage arm member  154  connected to and surrounding the cam  174  to move the stage  150 . A bearing ring may be used between the cam  174  and the stage arm member  154 . 
     Additionally, when the pivot motor  220  moves the pivot motor shaft  186  rotates. There is a pivot eccentric cam member  176  attached to the pivot motor shaft  186 . When the pivot motor shaft  186  rotates the pivot eccentric cam  176  rotates and the cam design causes the pivot arm member  154  connected to and surrounding the cam  176  to move the pivot arm  156  back and forth which causes the stage  150  to move relative to the pivot arm  156 . A bearing ring may be used between the cam  176  and the pivot arm  156 . 
     As the stage  150  and pivot arm  154  move, the stage stabilizing arms  152  move along the upper stage skid pads and the lower stage skid pad  151  (e.g., as in  FIG.  13   ) to stabilize the stage  150  during movement. Further, the stage eccentric  174  and pivot eccentric  176  can include a boss. The boss gives the eccentric  174 ,  176  some extra material to house the set screw which clamps on the stage motor shaft  184  or pivot motor shaft  186 , thus securely attaching it to the respective eccentric  174 ,  176 . The pivot eccentric boss  187  is seen in  FIG.  21   . The stage eccentric boss is not shown in the figures as it is flipped relative to the pivot boss  187  because the stage  150  and the pivot arm  156  are operating on different planes. 
     Although various acts are described herein according to the exemplary method of this disclosure, it is to be understood that some of the acts described herein may be omitted, and others may be added without departing from the scope of this disclosure. 
     It will be recognized by those skilled in the art that changes or modifications may be made to the above described embodiments without departing from the broad concepts of the disclosure. It is understood therefore that the disclosure is not limited to the particular embodiments which are described, but is intended to cover all modifications and changes within the scope and spirit of the disclosure. 
     The systems described herein may provide multiple ones of any or each of those components and these components may be provided on either a standalone machine or, in some embodiments, on multiple machines in a distributed system. The systems and methods described herein may be implemented as a method, apparatus or article of manufacture using programming or engineering techniques to produce software, firmware, hardware, or any combination thereof. In addition, the systems and methods described herein may be provided as one or more computer-readable programs embodied on or in one or more articles of manufacture. The term “article of manufacture” as used herein is intended to encompass code or logic accessible from and embedded in one or more computer-readable devices, firmware, programmable logic, memory devices (e.g., EEPROMs, ROMs, PROMs, RAMs, SRAMs), hardware (e.g., integrated circuit chip, Field Programmable Gate Array (FPGA), Application Specific Integrated Circuit (ASIC)), electronic devices, a computer readable non-volatile storage unit (e.g., CD-ROM, floppy disk, hard disk drive). The article of manufacture may be accessible from a file server providing access to the computer-readable programs via a network transmission line, wireless transmission media, signals propagating through space, radio waves, or infrared signals. The article of manufacture may be a flash memory card or a magnetic tape. The article of manufacture includes hardware logic as well as software or programmable code embedded in a computer readable medium that is executed by a processor. In general, the computer-readable programs may be implemented in any programming language, such as LISP, PERL, C, C++, PROLOG, or in any byte code language such as JAVA. The software programs may be stored on or in one or more articles of manufacture as object code. 
     Having described certain embodiments of methods and systems for virtualizing audio hardware for one or more virtual machines, it will now become apparent to one of skill in the art that other embodiments incorporating the concepts of the disclosure may be used. 
     While various embodiments have been described and illustrated herein, those of ordinary skill in the art will readily envision a variety of other means or structures for performing the function or obtaining the results or one or more of the advantages described herein, and each of such variations or modifications is deemed to be within the scope of the embodiments described herein. More generally, those skilled in the art will readily appreciate that all parameters, dimensions, materials, and configurations described herein are meant to be exemplary and that the actual parameters, dimensions, materials, or configurations will depend upon the specific application or applications for which the teachings are used. Those skilled in the art will recognize, or be able to ascertain using no more than routine experimentation, equivalents to the specific embodiments described herein. It is, therefore, to be understood that the foregoing embodiments are presented by way of example only and that, within the scope of the appended claims and equivalents thereto, embodiments may be practiced otherwise than as specifically described and claimed. Embodiments of the present disclosure are directed to each individual feature, system, article, material, kit, or method described herein. In addition, any combination of two or more such features, systems, articles, materials, kits, or methods, if such features, systems, articles, materials, kits, or methods are not mutually inconsistent, is included within the scope of the present disclosure. 
     The above-described embodiments can be implemented in any of numerous ways. For example, the embodiments may be implemented using hardware, software or a combination thereof. When implemented in software, the software code can be executed on any suitable processor or collection of processors, whether provided in a single computer or distributed among multiple computers. 
     Also, a computer may have one or more input and output devices. These devices can be used, among other things, to present a user interface. Examples of output devices that can be used to provide a user interface include printers or display screens for visual presentation of output and speakers or other sound generating devices for audible presentation of output. Examples of input devices that can be used for a user interface include keyboards, and pointing devices, such as mice, touch pads, and digitizing tablets. As another example, a computer may receive input information through speech recognition or in other audible format. 
     Such computers may be interconnected by one or more networks in any suitable form, including a local area network or a wide area network, such as an enterprise network, and intelligent network (IN) or the Internet. Such networks may be based on any suitable technology and may operate according to any suitable protocol and may include wireless networks, wired networks or fiber optic networks. 
     A computer employed to implement at least a portion of the functionality described herein may comprise a memory, one or more processing units (also referred to herein simply as “processors”), one or more communication interfaces, one or more display units, and one or more user input devices. The memory may comprise any computer-readable media, and may store computer instructions (also referred to herein as “processor-executable instructions”) for implementing the various functionalities described herein. The processing unit(s) may be used to execute the instructions. The communication interface(s) may be coupled to a wired or wireless network, bus, or other communication means and may therefore allow the computer to transmit communications to or receive communications from other devices. The display unit(s) may be provided, for example, to allow a user to view various information in connection with execution of the instructions. The user input device(s) may be provided, for example, to allow the user to make manual adjustments, make selections, enter data or various other information, or interact in any of a variety of manners with the processor during execution of the instructions. 
     The various methods or processes outlined herein may be coded as software that is executable on one or more processors that employ any one of a variety of operating systems or platforms. Additionally, such software may be written using any of a number of suitable programming languages or programming or scripting tools, and also may be compiled as executable machine language code or intermediate code that is executed on a framework or virtual machine. 
     The concept described herein may be embodied as a computer readable storage medium (or multiple computer readable storage media) (e.g., a computer memory, one or more floppy discs, compact discs, optical discs, magnetic tapes, flash memories, circuit configurations in Field Programmable Gate Arrays or other semiconductor devices, or other non-transitory medium or tangible computer storage medium) encoded with one or more programs that, when executed on one or more computers or other processors, perform methods that implement the various embodiments described herein. The computer readable medium or media can be transportable, such that the program or programs stored thereon can be loaded onto one or more different computers or other processors to implement various aspects and embodiments described herein. 
     The terms “program” or “software” are used herein in a generic sense to refer to any type of computer code or set of computer-executable instructions that can be employed to program a computer or other processor to implement various aspects of embodiments as discussed above. Additionally, according to one aspect, one or more computer programs that when executed perform methods or operations described herein need not reside on a single computer or processor, but may be distributed in a modular fashion amongst a number of different computers or processors to implement various aspects or embodiments described herein. 
     Computer-executable instructions may be in many forms, such as program modules, executed by one or more computers or other devices. Generally, program modules include routines, programs, objects, components, or data structures that perform particular tasks or implement particular abstract data types. Typically the functionality of the program modules may be combined or distributed as desired in various embodiments. 
     The data structures may be stored in computer-readable media in any suitable form. For simplicity of illustration, data structures may be shown to have fields that are related through location in the data structure. Such relationships may likewise be achieved by assigning storage for the fields with locations in a computer-readable medium that convey relationship between the fields. Any suitable mechanism may be used to establish a relationship between information in fields of a data structure, including through the use of pointers, tags or other mechanisms that establish relationship between data elements. 
     The concepts described herein may be embodied as one or more methods, of which an example has been provided. The acts performed as part of the method may be ordered in any suitable way. Accordingly, embodiments may be constructed in which acts are performed in an order different than illustrated, which may include performing some acts simultaneously, even though shown as sequential acts in illustrative embodiments. 
     As used herein, the terms “light”, “optical” and related terms should not but understood to refer solely to electromagnetic radiation in the visible spectrum, but instead generally refer to electromagnetic radiation in the ultraviolet (about 10 nm to 390 nm), visible (390 nm to 750 nm), near infrared (750 nm to 1400 nm), mid-infrared (1400 nm to 15,000 nm), and far infrared (15,000 nm to about 1 mm). 
     The indefinite articles “a” and “an,” as used herein in the specification and in the claims, unless clearly indicated to the contrary, should be understood to mean “at least one.” 
     References to “or” may be construed as inclusive so that any terms described using “or” may indicate any of a single, more than one, and all of the described terms. 
     In the claims, as well as in the specification above, all transitional phrases such as “comprising,” “including,” “carrying,” “having,” “containing,” “involving,” “holding,” “composed of,” and the like are to be understood to be open-ended, i.e., to mean including but not limited to.