Abstract:
In accordance with the invention, provides is a auto-navigating vehicle, that include a payload portion configured to hold or pull a payload, a drive system configured to cause the vehicle to drive, stop, and steer, the drive system including drive controls that enable a non-remote operator to drive the vehicle from an operator area proximate to the drive controls, a sensor head configured to detect information indicating the absence and presence of objects in an environment, a navigation system operatively coupled to the drive system and sensor head and configured to auto-navigate the vehicle through the environment without operator drive control. The sensor head is oriented above the drive controls and between the drive controls and payload portion, such that the sensor head is substantially out of a field of view of an operator when in the operator area.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application claims the benefit of priority under 35 U.S.C. §119(e) from provisional application Ser. No. 61/581,863, entitled ROBOTIC VEHICLE WITH OPERATOR FIELD OF VIEW ENHANCING SENSOR POSITIONING AND METHOD OF ACCOMPLISHING SAME, filed on Dec. 30, 2011, which is incorporated herein by reference in its entirety. 
     
    
     FIELD OF INTEREST 
       [0002]    The present inventive concepts relate to the field of robotic, self-navigating, and auto-navigating vehicles, and more particularly to such vehicles with available hands-on operator control. 
       BACKGROUND 
       [0003]    Robots, generally, can be used in a wide variety of contexts, industrial, military, and personal. Some robots have no capacity or intention for hands-on operator interaction to perform their tasks, e.g., robotic vacuum cleaners and unmanned aerial vehicles. Other robots do, however, require or accommodate direct (non-remote) user interaction during operation. 
         [0004]    Robotic, self-navigating, and auto-navigating vehicles (collectively “auto-navigating vehicles”) are vehicles that move autonomously from place to place. While some auto-navigating vehicles do not anticipate or accommodate hands-on operation by a human operator, some auto-navigating vehicles do anticipate, or at lest accommodate, human operators being aboard for the performance of certain tasks. For example, auto-navigating pallet trucks and tuggers can have robotic navigation ability, where a human operator can ride along to perform tasks once the auto-navigating vehicle arrives at its destination. 
         [0005]    A warehouse, which is primarily used for the storage of goods for commercial purposes, is a facility having increased utility for robots and auto-navigating vehicles. The storage provided by a warehouse is generally intended to be temporary, as such goods ultimately may be intended for a retailer, consumer or customer, distributor, transporter or other subsequent receiver. A warehouse can be a standalone facility, or can be part of a multi-use facility. Thousands of types of items can be stored in a typical warehouse. The items can be small or large, individual or bulk. It is common to load items on a pallet for transportation, and the warehouse may use pallets as a manner of internally transporting and storing items. 
         [0006]    A well-run warehouse is well-organized and maintains an accurate inventory of goods. Goods can come and go frequently, throughout the day, in a warehouse. In fact, some large and very busy warehouses work three shifts, continually moving goods throughout the warehouse as they are received or needed to fulfill orders. Shipping and receiving areas, which may be the same area, are the location(s) in the warehouse where large trucks pick-up and drop-off goods. The warehouse can also include a staging area—as an intermediate area between shipping and receiving and storage aisles and areas within the warehouse where the goods are stored. The staging area, for example, can be used for confirming that all items on the shipping manifest were received in acceptable condition. It can also be used to assemble or otherwise prepares orders for shipping. 
         [0007]    Goods in a warehouse tend to be moved in one of two ways, either by pallet or by cart (or trailer). A pallet requires a pallet transport for movement, such as a pallet jack, pallet truck, forklift, or stacker. A stacker is a piece of equipment that is similar to a fork lift, but can raise the pallet to significantly greater heights, e.g., for loading a pallet on a warehouse shelf. A cart requires a tugger (or “tow cart”), which pulls the cart from place to place. 
         [0008]    A pallet transport can be manual or motorized. A traditional pallet jack is a manually operated piece of equipment, as is a traditional stacker. When a pallet transport is motorized, it can take the form of a powered pallet jack, pallet truck, or forklift (or lift truck). A motorized stacker is referred to as a power stacker. A motorized pallet jack is referred to as a powered pallet jack, which an operator cannot ride, but walks beside. A pallet truck is similar to a powered pallet jack, but includes a place for an operator to stand. 
         [0009]    As with motorized pallet transports, a tugger can be in the form of a drivable vehicle or in the form of a powered vehicle along the side of which the operator walks. In either form, a tugger includes a hitch that engages with a companion part on the cart, such as a sturdy and rigid ring or loop. 
         [0010]    Pallet transports, tuggers, and other vehicles that transport goods in a warehouse or similar setting can be generally referred to as “warehouse vehicles.” 
         [0011]      FIG. 1  is a side view of a pallet truck  100 , as an example of a warehouse transport vehicle. The pallet truck  100  includes a rear payload portion  110 , where a pair of forks  112  is located to engage and lift a pallet. The forks  112  can be raised and lowered. As is known in the art, the forks  112  are lowered to engage the pallet, and then raised to lift the pallet from the floor. Once the pallet is lifted, the pallet truck  100  can transport the pallet to another location, using load wheels  114  located in distal ends of the forks  112 . 
         [0012]    Pallet truck  100  includes a front drive portion  120  that includes a housing  122 , within which may be located a motor and drive mechanisms (not shown). Within, or adjacent to, housing  122  is a battery compartment  123 . A wheel  125  is also located in the front drive portion  120 , usually beneath a linkage (not shown). A set of wheels  116  is forwardly located between the front wheel  125  and an operator area  128 , which includes platform  127  for supporting an operator  50  during transportation. A back rest  130  defines a back of the operator area  128 , and separates operator  50  from pallets loaded on forks  112 . Pallet truck  100  is operator controlled using a set of drive controls  124 , which include steering, start, drive, and stop mechanisms. 
       SUMMARY 
       [0013]    In accordance with one aspect of the present invention, provided is an auto-navigating vehicle. The vehicle comprises a payload portion configured to hold or pull a payload, a drive system configured to cause the vehicle to drive, stop, and steer, the drive system including drive controls that enable a non-remote operator to drive the vehicle from an operator area proximate to the drive controls, a sensor head configured to detect information indicating the absence and presence of objects in an environment, a navigation system operatively coupled to the drive system and sensor head and configured to auto-navigate the vehicle through the environment without operator drive control. The sensor head is oriented above the drive controls and between the drive controls and payload portion, such that the sensor head is substantially out of a field of view of an operator when in the operator area. 
         [0014]    In various embodiments, the sensor head can be a camera head comprising one or more stereo cameras. 
         [0015]    In various embodiments, the camera head can include a plurality of stereo cameras providing a combined camera field of view of about 360 degrees in a plane parallel to a ground surface. 
         [0016]    In various embodiments, the vehicle can further comprise a mast that supports the sensor head. 
         [0017]    In various embodiments, the vehicle may be a rideable vehicle comprising, in the operator area, an operator platform configured to hold the operator and a back rest disposed between the operator platform and the payload portion. The sensor head can be coupled to the backrest. 
         [0018]    In various embodiments, the payload portion can comprise a movable payload portion and the sensor head remains stationary as the movable payload portion moves vertically. 
         [0019]    In various embodiments, the vehicle can be an auto-navigating pallet truck and the movable payload portion is a pair of forks. 
         [0020]    In various embodiments, the payload portion can comprise a movable payload portion and the sensor head can move vertically when the movable payload portion moves vertically. 
         [0021]    In various embodiments, vehicle can be an auto-navigating pallet truck and the movable payload portion can be a pair of forks. 
         [0022]    In various embodiments, the vehicle can further comprise at least one position detector configured to determine a movement of the sensor head and to provide offset information indicating such movement to the navigation system. 
         [0023]    In various embodiments, the navigation system can be configured to adjust sensor data received from the sensor head using an offset determined from the offset information. 
         [0024]    In various embodiments, the navigation system can include and can be configured to update an evidence grid that represents the environment using the adjusted sensor data. 
         [0025]    In various embodiments, the environment can be a warehouse. 
         [0026]    In various embodiments, the robotic vehicle can be an auto-navigating tugger and the operator area can be in front of the vehicle. 
         [0027]    In accordance with another aspect of the invention, provided is an auto-navigating warehouse vehicle. The vehicle comprises a first portion that is vertically stationary, the first portion including drive controls configured to provide operator drive control of the vehicle when in an operator area, a second portion defining a payload area, wherein the second portion is configured to raise and lower between a first position and a second position, and a sensor head that forms part of a navigation system, wherein the sensor head is disposed above the operator area and between the operator area and the payload area so that the sensor head does not obstruct a field of view of an operator in the operator area when the second portion is in either of the first position and the second position. 
         [0028]    In various embodiments, the operator area can be in the first portion. 
         [0029]    In various embodiments, the operator area can be in the second portion. 
         [0030]    In various embodiments, the operator area can be in front of the first portion. 
         [0031]    In various embodiments, the vehicle can further comprise at least one position detector configured to determine a movement of the sensor head and to provide offset information indicating such movement to the navigation system. 
         [0032]    In various embodiments, the navigation system can be configured to adjust sensor data received from the sensor head using an offset determined from the offset information. 
         [0033]    In accordance with another aspect of the invention, provided is a method of adjusting sensor data in an auto-navigating vehicle having a sensor head that can be moved between first and second positions. The method comprises providing a robotic vehicle, determining an offset of the sensor head when moved from a first position, and the navigation system adjusting the sensor data using the offset. The robotic vehicle can comprise a first portion that is vertically stationary, the first portion including drive controls configured to provide operator drive control of the vehicle when in an operator area, a second portion defining a payload area, wherein the second portion is configured to raise and lower between a first position and a second position, and a sensor head that forms part of a navigation system, wherein the sensor head is disposed above the operator area and between the operator area and the payload area so that the sensor head does not obstruct a field of view of an operator in the operator area when the second portion is in either of the first position and the second position. 
         [0034]    In accordance with one aspect of the present invention, provided is a robotic vehicle having a first portion that does not raise and lower, the first portion including drive mechanisms for driving the robotic vehicle, and a second portion that raises and lowers between a first position and a second position, the second portion including an operator platform. The robotic vehicle also includes a sensor head that forms part of an automated navigation system, wherein the sensor head is disposed above the operator platform so that the sensor head does not obstruct a field of view of an operator on the operator platform when the second portion is in either of the first position and the second position. 
         [0035]    The sensor head can be a camera head comprising one or more stereo cameras. 
         [0036]    The camera head can include a plurality of stereo cameras providing a combined camera field of view of about 360 degrees in a plane parallel to a ground surface. 
         [0037]    The robotic vehicle can further include a mast to which the sensor head is attached. 
         [0038]    The mast can be a single mast. 
         [0039]    The mast can be a double mast. 
         [0040]    The sensor head can be coupled to a backrest disposed between the operator platform and a payload portion of the robotic vehicle. 
         [0041]    The sensor head can remain stationary as the second portion moves between the first and second positions. 
         [0042]    The sensor head can move with the second portion as the second portion moves between the first and second positions. 
         [0043]    The robotic vehicle can further comprise at least one position detector configured to determine a movement of the sensor head and to provide offset information indicating such movement to the automated navigation system. 
         [0044]    The automated navigation system can be configured to adjust sensor data received from the sensor head using an offset determined from the offset information. 
         [0045]    The automated navigation system can include and update an evidence grid that represents an environment within which the robotic vehicle travels, and the automated navigation system can use the adjusted sensor data to navigate through the environment and to update the evidence grid. 
         [0046]    The environment can be a warehouse. 
         [0047]    The robotic vehicle can be a robotic pallet truck. 
         [0048]    The robotic vehicle can be a robotic tugger. 
         [0049]    In accordance with another aspect of the invention, provided is a method of adjusting sensor data in a robotic vehicle having a sensor head that can be moved between first and second positions. The method includes providing a robotic vehicle that includes a first portion including a drive mechanism coupled to a navigation processor and a second portion including a platform configured to support an operator. The robotic vehicle can also include a sensor head coupled to second portion and disposed above the operator platform so that the sensor head does not obstruct a field of view of an operator on the operator platform when the second portion is in either of a first position and a second position wherein the sensor head moves with the second portion as the second portion moves between the first and second positions. The method further includes determining an offset of the sensor head when moved from the first position and adjusting sensor data received by the navigation processor from the sensor head using the offset. 
         [0050]    In accordance with another aspect of the present invention, provided is a robotic vehicle configured for automated navigation. The robotic vehicle includes a first portion that does not raise and lower, the first portion including drive mechanisms for driving the robotic vehicle, a second portion that raises and lowers between a first position and a second position, the second portion including an operator platform, and a camera head that forms part of an automated navigation system. The camera head is disposed on a mast above the operator platform so that the camera head does not obstruct a field of view of an operator on the operator platform when the second portion is in either of a first position and a second position. 
         [0051]    The camera head can move with the second portion as the second portion moves between the first and second positions. 
         [0052]    The robotic vehicle can further include at least one position detector configured to determine a movement of the sensor head and to provide offset information indicating such movement to the automated navigation system. 
         [0053]    The automated navigation system can include and update an evidence grid that represents an environment within which the robotic vehicle travels, and the automated navigation system can use the adjusted sensor data to navigate through the environment and to update the evidence grid. 
         [0054]    In accordance with the present invention, provided is a robotic vehicle that includes a vision system configured for automated navigation, wherein the vision system includes a camera head attached to the robotic vehicle to avoid operator field of view obstruction when an operator platform of the robotic vehicle is in either of a first position and a second position. 
         [0055]    The robotic vehicle can be a robotic pallet truck or tugger. 
         [0056]    The second position can be a height that is greater than a height of the first position. 
         [0057]    The camera head can be attached to the robotic vehicle via at least one mast. 
         [0058]    The at least one mast can be a single mast. 
         [0059]    The at least one mast can be a double mast. 
         [0060]    The at least one mast can remain stationary relative to the operator platform, as the operator platform raises and lowers. 
         [0061]    The at least one mast can raise and lower with the operator platform. 
         [0062]    The vision system can include a position sensor that detects relocation of the camera head. 
         [0063]    In accordance with another aspect of the present disclosure, provided is a robotic vehicle having a drive mechanism coupled to a navigation processor and memory configured to navigate the vehicle though a warehouse without operator control; a set of operator controls that enable the operator to optionally control the vehicle; an operator platform configured to support the operator such that the operator controls are accessible to the operator; at least one environment sensor coupled to the navigation processor and located on the vehicle above the operator platform such that when the operator is on the platform the sensor does not obstruct a field of view of the operator in a direction of travel of the vehicle. 
         [0064]    A vehicle configured for robotic or manual navigation within an environment including: a drive mechanism coupled to a automated navigation processor and a set of operator controls; a platform configured to support an operator at the controls during navigation; at least one sensor coupled to the navigation processor and secured to a mast that orients the at least one sensor above the operator without obstructing a field of view of the operator during navigation when the platform is in either of a first and a second position. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0065]    The present invention will become more apparent in view of the attached drawings and accompanying detailed description. The embodiments depicted therein are provided by way of example, not by way of limitation, wherein like reference numerals refer to the same or similar elements. The drawings are not necessarily to scale, emphasis instead being placed upon illustrating aspects of the invention. In the drawings: 
           [0066]      FIG. 1  is a side view of a pallet truck according to the prior art; 
           [0067]      FIG. 2  is a side view of a first embodiment of an auto-navigating warehouse vehicle, according to aspects of the present invention; 
           [0068]      FIGS. 3A-3D  are views of a second embodiment of an auto-navigating warehouse vehicle, according to aspects of the present invention; 
           [0069]      FIGS. 4A-4D  are views of a third embodiment of an auto-navigating warehouse vehicle, according to aspects of the present invention; 
           [0070]      FIGS. 5A-5D  are views of a fourth embodiment of an auto-navigating warehouse vehicle, according to aspects of the present invention; 
           [0071]      FIGS. 6A-6C  are views of a fifth embodiment of an auto-navigating warehouse vehicle, according to aspects of the present invention; and 
           [0072]      FIG. 7  is a block diagram of an embodiment of an automated navigation system that includes sensor position determination for an auto-navigating warehouse vehicle, according to aspects of the present invention. 
       
    
    
     DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS 
       [0073]    Various exemplary embodiments will be described more fully hereinafter with reference to the accompanying drawings, in which some exemplary embodiments are shown. The present inventive concept may, however, be embodied in many different forms and should not be construed as limited to the exemplary embodiments set forth herein. 
         [0074]    It will be understood that, although the terms first, second, etc. are be used herein to describe various elements, these elements should not be limited by these terms. These terms are used to distinguish one element from another, but not to imply a required sequence of elements. For example, a first element can be termed a second element, and, similarly, a second element can be termed a first element, without departing from the scope of the present invention. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. 
         [0075]    It will be understood that when an element is referred to as being “on” or “connected” or “coupled” to another element, it can be directly on or connected or coupled to the other element or intervening elements can be present. In contrast, when an element is referred to as being “directly on” or “directly connected” or “directly coupled” to another element, there are no intervening elements present. Other words used to describe the relationship between elements should be interpreted in a like fashion (e.g., “between” versus “directly between,” “adjacent” versus “directly adjacent,” etc.). 
         [0076]    The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. As used herein, the singular forms “a,” “an” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises,” “comprising,” “includes” and/or “including,” when used herein, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. 
         [0077]    Spatially relative terms, such as “beneath,” “below,” “lower,” “above,” “upper” and the like may be used to describe an element and/or feature&#39;s relationship to another element(s) and/or feature(s) as, for example, illustrated in the figures. It will be understood that the spatially relative terms are intended to encompass different orientations of the device in use and/or operation in addition to the orientation depicted in the figures. For example, if the device in the figures is turned over, elements described as “below” and/or “beneath” other elements or features would then be oriented “above” the other elements or features. The device may be otherwise oriented (e.g., rotated 90 degrees or at other orientations) and the spatially relative descriptors used herein interpreted accordingly. 
         [0078]      FIG. 2  is a side view of a first embodiment of a rideable auto-navigating warehouse vehicle with field-of-view (FOV) enhancing navigation sensor positioning, according to aspects of the present invention. In this embodiment, the auto-navigating warehouse vehicle takes the form of an auto-navigating pallet truck  200 . Where portions of the auto-navigating pallet truck  200  are similar to corresponding portions of the pallet truck  100  of  FIG. 1 , the same reference numbers are used. The auto-navigating pallet truck  200  includes at least one navigation processor, storage media and a sensor head mounted on a mast. In the embodiment of  FIG. 2 , the auto-navigating pallet truck  200  is configured with self-navigating capability so that, for example, it could self- or auto-navigate through a facility, such as a warehouse or the like. Therefore, while shown, operator  50  may be optional with respect to navigation. For example, operator  50  may ride along while the auto-navigating pallet truck  200  navigates (i.e., drives) through a warehouse environment. 
         [0079]    The navigation capability can be embodied in an apparatus that takes the form of at least one processor executing computer program code stored in at least one computer memory. The program code includes logic for navigating the warehouse transport vehicle (e.g., a pallet truck or other such vehicle) through an environment based on inputs from one or more sensors and preferably an electronic representation of the environment. Such processor or processors are operatively coupled to the start, stop, drive and steering mechanisms of the warehouse transport vehicle, in this embodiment, and to drive and navigate the auto-navigating warehouse transport vehicle through the environment. The hardware, software, and/or firmware comprising the navigation system can be located on the auto-navigating pallet truck  200  (e.g., within housing  122 ), remotely, or some combination thereof. 
         [0080]    As an example, in some embodiments, the navigation system can employ an evidence grid approach, where the evidence grid is automatically updated as the auto-navigating vehicle travels through the environment, e.g., using information gathered by sensor head  210 . The sensor head  210  can comprise one or more stereo cameras for collecting environmental data used for generating and updating a ma of the environment based on the evidence grid. For example, an auto-navigating warehouse vehicle in accordance with the present invention can use a navigation system that uses evidence grids as described in U.S. Pat. No. 7,446,766, entitled Multidimensional Evidence Grids And System And Methods For Applying Same, and/or U.S. Patent Pub. US 2009-0119010, entitled Multidimensional Evidence Grids and System and Methods for Applying Same. 
         [0081]    In  FIG. 2 , the sensor head  210  is movable in a vertical direction. The side view of the auto-navigating vehicle  200  shown in  FIG. 2  shows a rear-mounted mast  212 , which supports sensor head  210  and warning light (or light stack)  214 . In this embodiment, the mast  212  is coupled to, or made part of, the back rest  130 . Therefore, in this embodiment, the sensor head  210  (and light stack  214 ) moves vertically as the operator platform  127 , backrest  130 , and forks  112  raise and lower. In  FIG. 2 , the solid lines indicate the movable portions in a lowered (first) position. The dashed lines indicate movable portions of the pallet truck in a raised (second) position. In view of the vertical movement of the sensor head  210 , e.g., one or more stereo cameras, the navigation system may determine a camera head offset that can be used as an adjustment factor when updating the evidence grid. 
         [0082]    In some embodiments, the range of motion, which in this embodiment is vertical, can be known in advance and programmed into the navigation system used by the auto-navigating pallet truck  200 . The vertical displacement or movement of the camera head  210  will be the same as that of the operator platform  127 , backrest  130 , and forks  112 , in this embodiment. Therefore, detection, measurement, or calculation of the vertical change of distance or displacement can be determined with any of a variety of types of detectors and sensors. The determined vertical displacement can then be used as an adjustment or offset by the navigation system. 
         [0083]    In some embodiments, two different positions can be defined for the camera head, a first position when the operator platform  127 , backrest  130 , and forks  112  are lowered and a second position when the operator platform  127 , backrest  130 , and forks  112  are raised. In such a case, either the first position or the second position can be a “home” position and the offset can be preprogrammed for the other of the first and second positions. Therefore, only a detection or sensing of whether the operator platform  127 , backrest  130 , and forks  112  are raised or lowered would be required to determine whether or not to apply the offset within the navigation system. 
         [0084]    In  FIG. 2 , the movable mast  212  and sensor head  210  are positioned in a manner that does not obstruct the operator&#39;s  50  field of view (FOV) in the driving or forward direction, or other directions. And nothing on the auto-navigating pallet truck  200  materially obstructs the FOV of the sensor head  210 . 
         [0085]      FIGS. 3A-3D  provide different views of a second embodiment of a rideable auto-navigating warehouse vehicle with FOV enhancing navigation sensor positioning, according to aspects of the present invention. 
         [0086]      FIG. 3A  is a perspective view of the second embodiment of an auto-navigating warehouse vehicle in the form of a pallet truck  300 , which has a sensor head  310  and mast  312 .  FIG. 3B  provides a side view of the auto-navigating pallet truck  300  of  FIG. 3A .  FIG. 3C  provides a front view of the auto-navigating pallet truck  300  of  FIG. 3A . And  FIG. 3D  provides a top view of the auto-navigating pallet truck  300  of  FIG. 3A . 
         [0087]    As with the embodiment of  FIG. 2 , the auto-navigating pallet truck  300  of  FIGS. 3A-3D , the sensor head  310  can be or include a set of stereo cameras as a vision system, such as described in U.S. Pat. No. 7,446,766, entitled Multidimensional Evidence Grids and System and Methods for Applying Same, and/or U.S. Patent Pub. US 2009-0119010, entitled Multidimensional Evidence Grids and System and Methods for Applying Same. In various embodiments, the vision system can be or include a set of stereo cameras, such as those described in U.S. patent application Ser. No. 29/398127, filed Jul. 26, 2012, entitled Multi-Camera Head, which is incorporated herein by reference. Therefore, in various embodiments, the sensor head  310  may be referred to as camera head  310 , which will include one or more stereo cameras. In some embodiments, camera head  310  can include a plurality of stereo cameras providing a combined camera field of view of about 360 degrees in a plane parallel to a ground surface GS. 
         [0088]    In the embodiment of  FIGS. 3A-3D  the mast  312  and sensor head  310  are not vertically movable with the forks  112 . The back rest  130  does not move with the forks. Rather, a payload stop  115  defines a front end of the payload area  110 , and is coupled to and moves with the forks  112 . The operator platform  127  and operator area  128  also do not vertically move with the forks  112 . Therefore, the payload stop  115  and forks move vertically independent of the remaining portions of the auto-navigating pallet truck  300 . As a result, the sensor head  310  does not vertically move and associated offset and adjustment logic can be avoided. 
         [0089]    The sensor head  310  is located above and to the rear of the operator compartment  128 , such that it does not obstruct the view of an operator. And nothing on the auto-navigating pallet truck  300  materially obstructs the FOV of the sensor head  310 . 
         [0090]      FIGS. 4A-4D  provide different views of a third embodiment of an auto-navigating warehouse vehicle with FOV enhancing navigation sensor positioning, according to aspects of the present invention. 
         [0091]      FIG. 4A  is a perspective view of the auto-navigating warehouse vehicle in the form of a rideable auto-navigating tugger  400 , which has a sensor head  410  and mast  412 .  FIG. 4B  provides a side view of the auto-navigating tugger  400  of  FIG. 4A .  FIG. 4C  provides a front view of the auto-navigating tugger  400  of  FIG. 4A . And  FIG. 4D  provides a rear view of the auto-navigating tugger  400  of  FIG. 4A . 
         [0092]    The auto-navigating tugger  400  is configured with auto-navigation equipment, so that it could navigate through the warehouse without an operator, as discussed above. Where the navigation system requires a vision system, the sensor head  410  can include one or more stereo cameras and be referred to as a camera head  410 , as discussed above. In some embodiments, camera head  410  can include a plurality of stereo cameras providing a combined camera field of view of about 360 degrees in a plane parallel to a ground surface GS. 
         [0093]    The auto-navigating tugger  400  includes a platform  127  for supporting an operator, a operator area  128 , and a back rest  130 , as discussed above. Unlike the pallet trucks previously describer, the auto-navigating tugger does not include forks, or other payload portions, that raise and lower. Rather, the auto-navigating tugger  400  includes a hitch  420  configured to engage a cart, in a manner known in the art. Thus, the sensor head  410  will be substantially vertically stable, and secured to back rest  130  via the mast  412 . 
         [0094]    The sensor head  410  is located above and to the rear of the operator compartment  128 , such that it does not obstruct the view of an operator. And nothing on the auto-navigating pallet truck  400  materially obstructs the FOV of the sensor head  410 . 
         [0095]      FIGS. 5A-5D  provide different views of a fourth embodiment of an auto-navigating warehouse vehicle with FOV enhancing navigation sensor positioning, according to aspects of the present invention. 
         [0096]      FIG. 5A  is a perspective view of the auto-navigating warehouse vehicle in the form of a non-rideable auto-navigating pallet truck  500 , which has a sensor head  510  and mast  512 .  FIG. 5B  provides a side view of the auto-navigating pallet truck  500  of  FIG. 5A .  FIG. 5C  provides a front view of the auto-navigating pallet truck  500  of  FIG. 5A . And  FIG. 5D  provides a rear view of the auto-navigating pallet truck  500  of  FIG. 5A . 
         [0097]    The auto-navigating pallet truck  500  is configured with auto-navigation equipment, so that it could navigate through the warehouse without an operator, as discussed above. Where the navigation system requires a vision system, the sensor head  510  can include one or more stereo cameras, as discussed above. Here, since the auto-navigating pallet truck is not rideable, the operator area  128  is in front of the vehicle, proximate to the drive controls  124 . 
         [0098]    The auto-navigating pallet truck  500  has a handle  520  that includes the drive controls  124 . The mast  512  is connects to a main body  502  of the pallet truck  500  via an arm  514 . In this embodiment, the sensor head  510 , mast  512 , and arm  510  do not raise and lower with the forks  112 . Additionally, in this embodiment, the sensor head  510 , mast  512 , and arm  510  are located behind the handle  520  and the drive controls  124  such that they do not block a FOV of an operator when moving forward. And nothing on the auto-navigating pallet truck  500  materially obstructs the FOV of the sensor head  510 . 
         [0099]      FIGS. 6A-6C  provide different views of a fifth embodiment of an auto-navigating warehouse vehicle with FOV enhancing navigation sensor positioning, according to aspects of the present invention. 
         [0100]      FIG. 6A  is a side view of the auto-navigating warehouse vehicle in the form of a non-rideable auto-navigating pallet truck  600 , which has a sensor head  610  and mast  612 .  FIG. 6B  provides a front view of the auto-navigating pallet truck  600  of  FIG. 6A . And  FIG. 6C  provides a top view of the auto-navigating pallet truck  600  of  FIG. 6A . 
         [0101]    The auto-navigating pallet truck  600  is configured with auto-navigation equipment, so that it could navigate through the warehouse without an operator, as discussed above. Where the navigation system requires a vision system, the sensor head  610  can include one or more stereo cameras, as discussed above. Here, since the auto-navigating pallet truck is not rideable, the operator area  128  is in front of the vehicle, proximate to the drive controls  124 . 
         [0102]    The auto-navigating pallet truck  600  has a handle  620  that includes the drive controls  124 . In this embodiment, the sensor head  610  is secured to a mast  612 , which connects to a main body  620  of the auto-navigating pallet truck  600 . In this embodiment, the mast  612  is configured to raise and lower with the forks  112 . 
         [0103]    In this embodiment, the sensor head  610  is movable in a vertical direction. The side view of the auto-navigating vehicle  600  shown in  FIG. 6A  shows a rear-mounted mast  612 , which supports sensor head  610 . In this embodiment, the sensor head  610  moves vertically as the forks  112  raise and lower. In view of the vertical movement of the sensor head  610 , e.g., one or more stereo cameras, the navigation system may determine a camera head offset that can be used as an adjustment factor when updating an evidence grid map or the like used in the auto-navigation. 
         [0104]    In some embodiments, the range of motion, which in this embodiment is vertical, can be known in advance and programmed into the navigation system used by the auto-navigating pallet truck  600 . The vertical displacement or movement of the camera head  610  will be the same as that of the forks  112 , in this embodiment. Therefore, detection, measurement, or calculation of the vertical change of distance or displacement can be determined with any of a variety of types of detectors and sensors. The determined vertical displacement can then be used as an adjustment or offset by the navigation system. 
         [0105]    In some embodiments, two different positions can be defined for the camera head, a first position when the forks  112  are lowered and a second position when the forks  112  are raised. In such a case, either the first position or the second position can be a “home” position and the offset can be preprogrammed for the other of the first and second positions. Therefore, only a detection or sensing of whether the forks  112 , mast  610 , or sensor head  610  are raised or lowered would be required to determine whether or not to apply the offset within the navigation system. 
         [0106]    Additionally, in this embodiment, the sensor head  610  and mast  612  are located behind the handle  620  and the drive controls  124  such that they do not block a FOV of an operator when moving forward. And nothing on the auto-navigating pallet truck  600  materially obstructs the FOV of the sensor head  610 . 
         [0107]      FIG. 7  is a block diagram of an embodiment of an automated navigation system that includes sensor position determination for an auto-navigating warehouse vehicle, according to aspects of the present invention. 
         [0108]    The navigation system  700  includes sensor position determination capability for an auto-navigating vehicle, such as those shown and described herein and those not explicitly shown and described herein but reasonably understood to fall within the context and scope of the present invention. A navigation processor  710  can perform the primary computer-based functioning of the navigation system, such as send control information to a vehicle drive system of the robotic vehicle, e.g., auto-navigating pallet truck or tugger, as discussed above. In this embodiment, navigation processor  710  uses an evidence grid stored in a storage media  712  that represents the environment for navigation. Storage media  712  can be or include, for example, a non-transitory electronic, magnetic, or optical storage device. The navigation processor  710  can user data from sensor(s)  702 , e.g., camera head  310 , to determine a location of the robotic vehicle within the environment, using the evidence grid as a frame of reference. Navigation processor  710  can also use the sensor data to update the evidence grid. 
         [0109]    Position sensors/detectors  704  can detect, sense, or otherwise determine the position of the sensor(s)  702 , e.g., whether camera head  310  is in the first position, second position, or somewhere in between if called for by the particular embodiment. The information can be provided by the position sensor/detector  704  to the navigation processor  710  as offset information. Accordingly, the navigation processor  710  takes the offset into account when determining location of the auto-navigating warehouse vehicle relative to the evidence grid and when updating the evidence grid. 
         [0110]    As a result, the mast and sensor (or camera) head can be positioned on a auto-navigating warehouse (or robotic) vehicle without obstructing the field of view of the operator, whether the operator platform or payload area are in a lowered or raised position. 
         [0111]    Coupling the mast and sensor (e.g., camera) head to the robotic vehicle away from the drive portion of the robotic vehicle can also significantly reduce vibration at the sensor (e.g., camera) head and, consequently, reduce errors in the navigation system. 
         [0112]    While the foregoing has described what are considered to be the best mode and/or other preferred embodiments, it is understood that various modifications can be made therein and that the invention or inventions may be implemented in various forms and embodiments, and that they may be applied in numerous applications, only some of which have been described herein. It is intended by the following claims to claim that which is literally described and all equivalents thereto, including all modifications and variations that fall within the scope of each claim.