Abstract:
A remote sensing angle gauge includes a sensor responding to physical stimulus and transmitting a resulting impulse for measuring an angle, and a user interface separate and remote from said sensor and in communication with said sensor unit. The user interface receives a signal from the resulting impulse of said sensor unit, and determines the angle measurement according to the received signal from said sensor unit and inputted data from said interface unit. The inputted data by a user includes an offset and orientation of the sensor. The gauge can be zeroed before initiating the measurement. The sensor can be connected to the user interface through a detachable electrical connection. The sensor can include an adaptor accommodating a detachable and adjustable connection to an area being measured. The results of the measurement on the user interface can be remotely monitored, while measuring the angle with the sensor.

Description:
FIELD OF THE INVENTION 
   The present invention relates generally to a measurement apparatus and technique. More particularly, the present invention relates to an angle measurement apparatus and technique with a remote sensor. 
   BACKGROUND OF THE INVENTION 
   Accurate measurement of angles is important in a variety of fields including for example the manufacturing industries such as the automotive field. Measurement of such angles is also critical and difficult when being limited in confined spaces. 
   For example, proper alignment of wheels of an automotive vehicle is important for both proper handling of the vehicle, as well as proper tire wear. One of the wheel alignment parameters, which is measured and adjusted in order to achieve proper wheel alignment, is the caster angle. 
   Caster is an angle which the steering axis of a steerable wheel makes with respect to a vertical plane which is perpendicular to the longitudinal direction of the vehicles. The caster angle is considered positive when the steering axis is inclined rearward (in the upward direction) and negative when the steering axis is inclined forward. Caster can be measured by inclinometers attached to the wheel. To measure caster, the wheel is turned through an arc, and the difference in camber readings is used to derive the caster value. The camber angle is the inclination of the wheel plane with respect to the vertical. The camber angle is another parameter that is used for wheel alignment along with the caster angle. 
   Current wheel alignment tools are not able to accurately measure the caster angle in a convenient, efficient and accurate manner. Current angle measurement tools are large and the reading of measurements is difficult when measuring the angles due to low clearance or inaccessibility. For example, current angle gauges will not fit in confined spaces where the rear casters of the vehicles are located. Further, the current equipment is unable to include a remote display of the angle that is required when measuring in an inaccessible space, while displaying the measurement in a convenient and efficient manner. 
   Other wheel alignment tools can be placed underneath the car to take measurements of the angles. However, even laser range finders cannot get an accurate measurement. 
   In some recent models of vehicles, such as the 2006 versions of the PONTIAC SOLSTICE and SATURN SKY from GENERAL MOTORS, Inc., the vehicles have adjustable rear casters. In an effort to achieve mass reductions, GENERAL MOTORS made the decision to have a body rear structure that eliminated the rear frame. There is a need to measure the adjustable rear casters. However, the confined space available for the measurement of the caster angle and the size of the current tools make it very difficult to measure the angles. Thus the conventional tools cannot be used to measure angles, such as the caster angle of certain vehicles. 
   Accordingly, it is desirable to provide a technique and apparatus for measuring angles in confined spaces while still being able to display the measurement in a convenient manner for the user. 
   SUMMARY OF THE INVENTION 
   The foregoing needs are met, to a great extent, by the present invention, wherein in one aspect an apparatus and technique are provided that in some embodiments allows the user to measure angles in confined spaces while still allowing the user to efficiently input instructions and receive the angle measurements without interference. 
   In accordance with one embodiment of the present invention, a remote sensing angle gauge is provided, and can include a sensor unit including a sensor responding to physical stimulus and transmitting a resulting impulse for measuring an angle, and an interface unit separate and remote from the sensor unit and in communication with the sensor unit, the interface unit receiving a signal from the resulting impulse of the sensor unit, the interface unit determining the angle measurement according to the received signal from the sensor unit and inputted data from the interface unit. 
   In accordance with another aspect of the present invention, a method of remotely sensing an angle is provided, including setting a zero point with respect to an area being measured, receiving an offset value from an input unit and storing the offset value in a memory unit, receiving through an input unit a selection of an orientation of a sensor, and determining the angle measurement according to the data received from the sensor and input signals received for the offset value, and orientation of the sensor. 
   In accordance with yet another embodiment of the present invention, an apparatus for angle measurement is provided, and a sensor unit including a housing enclosing a sensor responding to physical stimulus and transmitting a resulting impulse for measuring an angle, and an interface unit in communication with the sensor unit, the interface unit receiving a signal from the resulting impulse of the sensor unit, the interface unit determining the angle measurement according to the received signal from the sensor unit and inputted data from the interface unit. 
   There has thus been outlined, ratherbroadly, certain embodiments of the invention in order that the detailed description thereof herein may be better understood, and in order that the present contribution to the art may be better appreciated. There are, of course, additional embodiments of the invention that will be described below and which will form the subject matter of the claims appended hereto. 
   In this respect, before explaining at least one embodiment of the invention in detail, it is to be understood that the invention is not limited in its application to the details of construction and to the arrangements of the components set forth in the following description or illustrated in the drawings. The invention is capable of embodiments in addition to those described and of being practiced and carried out in various ways. Also, it is to be understood that the phraseology and terminology employed herein, as well as the abstract, are for the purpose of description and should not be regarded as limiting. 
   As such, those skilled in the art will appreciate that the conception upon which this disclosure is based may readily be utilized as a basis for the designing of other structures, methods and systems for carrying out the several purposes of the present invention. It is important, therefore, that the claims be regarded as including such equivalent constructions insofar as they do not depart from the spirit and scope of the present invention. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a perspective view illustrating a remote digital angle gauge according to a preferred embodiment of the invention. 
       FIG. 2  is a block diagram of the internal modules of the remote digital angle gauge of  FIG. 1 . 
       FIG. 3  is a top or bottom view of the remote sensor unit of  FIG. 1 . 
       FIG. 4  is a side view of an alternative embodiment of the remote sensing digital angle gauge with an adaptor mechanism attachment. 
       FIG. 5  illustrates the angle measurement in the area shown in  FIG. 4 . 
       FIG. 6  illustrates the technique of determining the angle measurement in the remote sensing digital angle gauge. 
   

   DETAILED DESCRIPTION 
   The invention will now be described with reference to the drawing figures, in which like reference numerals refer to like parts throughout. An embodiment in accordance with the present invention provides a remote sensing angle gauge, including a remote sensor for measuring an angle, and a user interface separate and remote from the sensor and in communication with the sensor. The user interface receives a signal from the resulting impulse of the sensor, and the user interface unit determines the angle measurement according to the received signal from the sensor and inputted data from the user interface. The present invention also provides a technique of remotely sensing an angle, including setting a zero point with respect to an area being measured, receiving an offset value from an input unit and storing the offset value in a memory, receiving through an input unit a selection of an orientation of the sensor, and determining the angle measurement according to the data received from the sensor and input signals received for the offset value, and orientation of the sensor. Thus, the angle gauge and the technique of the angle gauge provide a user an accurate way to measure angles in confined spaces, efficiently input instructions and receive the measured angle measurements remotely without interference. 
   An embodiment of the present inventive apparatus is illustrated in  FIG. 1 . In one embodiment, the apparatus of the present invention is a digital angle gauge  10  with a user interface unit  12  and a sensor unit  14  (discussed below). The user interface  12  includes a display unit  16  and an array of indicators  18 . The display unit  16  will display, for example, the angle measurement, while the array of indicators  18  will inform the user of the function being used (further discussed below). The display unit  16  can be a digital display. The display unit  16  can be, for example, a liquid crystal display or other display unit capable of displaying alphanumerical and/or numerical values. 
     FIG. 2  is a block diagram of the internal modules of the remote digital angle gauge of  FIG. 1 . The display  16  is controlled by a central processing unit  24  (discussed below) and by the driver  44 . The array of indicators  18  can include, for example, light emitting diodes or other indicators capable of signaling to the user of the function being used. The user may select the different functions of the digital angle gauge through input keys such as the function up and down keys  20  and activate one of the input keys  20  for entering the selection. When a certain function is selected, the particular indicator such as the light emitting diode  18  is activated to show the function being used. Each one of the indicators  18  can be labeled to inform the user with regard to the significance of each one of the indicators  18 . For example, one indicator  18  may stand for the angle measurement of the driver side, another represents the angle measurement for the passenger side, while a third indicator  18  can represent zeroing function and a fourth indicator  18  represents an offset function. Other functions can also be included that relate to the angle measurement. The different functions of the digital angle gauge  10  will be described below. 
   The sensor unit  14  can connected to the user interface unit  12  through a wire or wirelessly. When the user interface unit is connected to the sensor unit through a wire  46  as seen in  FIGS. 1 and 2 , a coiled type cord such as a telephone type cord can be used to make the wire management efficient, while allowing the user to reach the sensor unit into certain confined spaces. The wire  46  between the sensor unit  14  and the user interface unit  12  can be a certain length and can be detachable or fixed as desired. 
   Referring to  FIG. 6 , the sensor unit  14  can communicate wirelessly to the user interface unit  12  through wireless protocols such as BLUETOOTH, IEEE (Institute of Electrical and Electronic Engineers) 802.11, etc. The user interface unit  12  can also include a fastening portion  62  that allows the user interface unit  12  to be attached to a stationary object for a hands-free reading by the user while measuring the angle. For example, the fastening portion  62  can be a self-storing support such as a hook or other mechanism capable of hanging the user interface unit beneath the vehicles to be measured. 
   Turning back to  FIG. 2 , the user interface unit  12  of the digital angle gauge  10  includes the central processing unit (CPU) or controller  24  that controls the digital angle gauge  10 . The CPU is connected with a memory unit  26  that stores data and instructions that are used by the digital angle gauge  10 . The memory unit  26  can be a computer readable media. A user can input data and instruction into the digital angle gauge  10  through one of the keys in the input unit  20 . The indicators  18  and display unit  16  are also controlled by the CPU  24 . The user interface unit  12  is encased in an assembly  32 . The digital angle gauge  10  can be powered by a power source  42 , which can be a primary (non-rechargeable) battery such as an alkaline battery, or a secondary battery (rechargeable battery) such as a lithium ion, lithium polymer, nickel metal hydride (NiMH), etc. The power supply  42  can also be a connection to an external power source. 
   Through an interface  28  on the user interface unit  12 , the interface unit  12  is connected to the sensor unit  14  by a wire  46  as seen in  FIG. 2  or a wireless communication link as seen in  FIG. 6 . The sensor unit  14  is encased by an assembly  22  and includes a sensor  36 . The sensor  34  can further include an accelerometer to sense change in the movement of the assembly  22 . The change in movement is displayed as an angle measured in degrees via the display on the user interface unit  12 . As states above, the sensor unit  14  can communicate the measured angles via a wire or wireless connection. The sensor  34  can also be detachable to accommodate the replacement of the sensor independent of the remote display in terms of the user interface unit  12 . When the sensor unit  14  is wirelessly connected to the user interface unit  12 , the remote sensor unit  14  can also include a power supply of its own. The sensor unit  14 , for example, can be attached to the rear suspension on the vehicles, and used to measure the actual caster angle. 
   The sensor unit  14  is further illustrated in  FIGS. 3 and 4 . Referring to  FIG. 3 , the sensor unit includes a notch  38  centered on the back of the housing  22 . The notch  38  receives detachable pins  60  that allow the mounting of the sensor unit  14  to various parts of the vehicle in order for a user to take measurements in a more efficient manner. Mounting the sensor unit  14  in a confined space allows for a better measurement and the ability to reach into difficult to reach areas. The notch can include, for example, sections with thicknesses “a” and “b” and width “c” at the opening being greater than the thickness “d” at the closed portion of the notch. The notch  38  can have many other configurations and the above description in  FIG. 3  is not limited to the configuration shown. The configuration of the assembly  22  of the sensor unit  14  is also not limited to such a configuration, but may include various other shapes and sizes. The sensor assembly can be small enough and be in certain shapes to accommodate being placed in certain confined areas such as regions in a vehicle that require an angle measurement and avoids any interference from other portions of the vehicle that would prohibit an accurate measurement of the angle. 
   Referring to  FIG. 5 , the sensor unit  14  can be placed in confined space to measure an angle, while still allowing a user to monitor the angle measurement in a viewable location outside of the confined space through the separately located user interface unit  12 . As seen in  FIG. 5 , the small remote sensor  36  in the small sensor unit  14  accommodates for accurate angle measurements where conventional gages will not fit. Current wheel alignment tools do not allow for measuring the rear caster, but as seen in  FIG. 5 , the angle of the rear caster and a variety of other angle measurements can be made. The separation of the sensor unit  14  from the user interface  12  allows the remote use of the sensor  34  so that the user can measure angles where conventional inclinometers and angle meters will not fit. 
   The applications for measuring angles are not limited to the caster angle in vehicles. A plurality of other types of angle measurements can be made. The digital angle gauge  10  is universal in its application. The digital angle gauge, for example, can be used for the GENERAL MOTORS Y car and any other non-steerable (rear axle) caster angle measurement, steering wheel angle measurement, driveshaft angle measurement, and frame angle measurement, etc. An example of the angle measurement taken by the present invention is the measurement of the rear caster. Other uses include placing the gauge  10  on a building to measure any desired angles, use any type of vehicle, etc. Furthermore, the caster angle can be measured at any corner (wheel) of the vehicle. 
   Referring to  FIG. 6 , at step  100 , a user can activate the offset button by using one of the input keys  20 , thus lighting up one of the plurality of indicators  18  showing that the offset is being selected. The offset number is entered so that the user can get the proper reading of the gauge  10  as related to the service manual. For example, when the service manual states that the castor has to be three degrees positive, and the steering knuckle is cocked three degrees negative, then if the user were to measure from the zero point, the gauge would instead read zero. Therefore, rather than obtain such a reading, the user can enter an offset number so the user can get a proper reading from the gauge  10  as related to the service manual. If a user knows at zero, dead center (e.g., the position of a crank when it is in line with the connecting rod and not exerting torque), and a user knows that the steering knuckle is cocked a certain amount of degrees, a user can type the offset number in the user interface unit  12 . The offset number is stored in the memory unit  26  for use by the CPU  24 . 
   At step  110 , and referring to  FIG. 6 , the sensor unit  14  can be placed on the hoist that the vehicle is on and zeroed (step  110 ). A user may place the sensor on the hoist itself, and zero the sensor accordingly. The zeroing gives the starting point between the level of the vehicle and level of the earth so that there is a zeroing of the gauge  10  in relationship to the hoist that the vehicle is on and the vehicle itself. Alternatively, the offset can be entered after zeroing the gauge  10 , and therefore, steps  100  and  110  can be interchanged. The plurality of indicators  18  indicates to the user the selected menu, including illuminating a certain indicator when offset or zeroing is selected through the input keys  20 . 
   At step  120 , the user would position the sensor unit in the area to be measured. For example, the sensor unit  14  can be positioned in the vehicle to measure the angle, as seen in  FIG. 5 . Other examples include placing the sensor unit having the pins  60  ( FIG. 4 ) in machined holes in the area to be measured in order to accommodate proper attachment. A wide variety of adaptors can be used for the specific area or purpose of measurement. 
   As another example, but not limited by such a configuration, two dowel pins  60  are placed on the back portion of the sensor unit  14 . The sensor unit  14  is slotted and has a t-slot  38  as seen in  FIG. 3 . The two pins  60  fasten into the mating of the t-slot  38 , and the two pins  60  fit into the holes in the knuckle of the vehicle as seen in  FIG. 5 . The sensor unit  14  can be attached to the knuckle or spindle assembly. The gauge  10  with the t-slot  38  and pins  60  can accommodate any distance between the holes up to the limit of the length of the sensor unit  14 . Different center to center distances can be included for the pins  60  depending on the application. 
   The adaptor increases the universal applicability of the gauge  10  to a variety of different uses. The adaptor mechanism such as the pins  60  is adjustable and replaceable. An adaptor unit does not have to be used, but accommodates a fastening to an area to be measured, thus allowing user to free a hand when reading the measurement. 
   The adapter mechanism  60  can also be positioned relative to the sensor  34 . For example, as seen in  FIG. 3 , the notch  38  is centered on the back of the sensor housing allowing an accurate reading. The sensor unit  14  can be mounted with multiple adapters to accommodate the gauge  10  to fit in a variety of purposes including for example present and future vehicle applications. 
   Referring back to  FIG. 6 , at step  130  the user would then enter in the user interface unit  12  whether negative or positive angle of the castor. The driver side or passenger side is selected depending on the orientation of the sensor, thus giving a positive or negative reading. The appropriate indicator  18  would illuminate to indicate whether the passenger or driver side is selected. 
   At step  140 , the gauge  10  then determines the angle measurement and displays the information on the display unit  16  for reading by the user away from where the angle is being measured and/or in a location that the display unit is easy to read. The angle measurement is determined by the CPU  24  with access to the memory unit  26 , through the information received from the accelerometer sensor  36 . The information from the accelerometer sensor  36  is received through the interface  28  on the user interface unit  12 . The display unit  16  indicates whether the caster angle is positive or negative at any corner (wheel) of the vehicle. 
   The angle measurement can be stored in the memory  26  or it can be not stored in the memory  26 , but simply displayed on the display unit  16  for an indefinite or certain period of time, or until the gauge  10  is re-zeroed. 
   The gauge  10  is re-zeroed to accommodate another vehicle or other application. For example, different vehicles have different weights that would tilt the hoist in one direction or another and so the gauge should be re-zeroed again. Further, the gauge  10  can be manually turned off by using the input key  20  or automatically turned off after no activity for a certain period of time. 
   The order of the steps  100 - 140  are not limiting and maybe applied in a different order or multiple steps may be performed at the same time, and additional steps can be performed and also certain steps can be not performed. For example, if no offset value is needed, step  100  can be skipped, or if the gauge  10  does not have to be re-zeroed, the zeroing step  110  can be skipped. 
   The present invention can be realized as computer-executable instructions in computer-readable media. The computer-readable media includes all possible kinds of media in which computer-readable data is stored or included or can include any type of data that can be read by a computer or a processing unit. The computer-readable media include, for example, and not limited to storing media, such as magnetic storing media (e.g., ROMs, floppy disks, hard disk, and the like), optical reading media (e.g., CD-ROMs (compact disc-read-only memory), DVDs (digital versatile discs), re-writable versions of the optical discs, and the like), hybrid magnetic optical disks, organic disks, system memory (read-only memory, random access memory), non-volatile memory such as flash memory or any other volatile or non-volatile memory, other semiconductor media, electronic media, electromagnetic media, infrared, and other communication media such as carrier waves (e.g., transmission via the Internet or another computer). Communication media generally embodies computer-readable instructions, data structures, program modules or other data in a modulated signal such as the carrier waves or other transportable mechanism including any information delivery media. Computer-readable media such as communication media may include wireless media such as radio frequency, infrared microwaves, and wired media such as a wired network. Also, the computer-readable media can store and execute computer-readable codes that are distributed in computers connected via a network. The computer readable medium also includes cooperating or interconnected computer readable media that are in the processing system or are distributed among multiple processing systems that may be local or remote to the processing system. The present invention can include the computer-readable medium having stored thereon a data structure including a plurality of fields containing data representing the techniques of the present invention. 
   An example of a computer, but not limited to this example of the computer, that can read computer readable media that includes computer-executable instructions of the present invention includes a processor that controls the computer. The processor uses the system memory and a computer readable memory device that includes certain computer readable recording media. A system bus connects the processor to a network interface, modem or other interface that accommodates a connection to another computer or network such as the Internet. The system bus may also include an input and output interface that accommodates connection to a variety of other devices. 
   Although an example of the remote sensing digital angle gauge is shown using the gauge of  FIGS. 1 through 6 , it will be appreciated that other gauges can be used. Also, although the digital angle gauge is useful to measure the caster angle in the automotive field, it can also be used for any type of angle measurement in any field. 
   The many features and advantages of the invention are apparent from the detailed specification, and thus, it is intended by the appended claims to cover all such features and advantages of the invention which fall within the true spirit and scope of the invention. Further, since numerous modifications and variations will readily occur to those skilled in the art, it is not desired to limit the invention to the exact construction and operation illustrated and described, and accordingly, all suitable modifications and equivalents may be resorted to, falling within the scope of the invention.