Patent Publication Number: US-2022234596-A1

Title: Target alignment system and method for sensor calibration

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     The present application claims priority of U.S. provisional application Ser. No. 63/142,736 filed Jan. 28, 2021, which is hereby incorporated herein by reference in its entirety. 
    
    
     BACKGROUND AND FIELD OF THE INVENTION 
     The present invention is directed to a system and method for aligning a target and a vehicle relative to each other for calibration of a sensor on the vehicle, and in particular to a sensor mounted on or near a windshield of the vehicle. 
     The use of sensors are important in a number of automotive safety systems, such as an Advanced Driver Assistance System (ADAS) for a vehicle. A conventional ADAS system will utilize one or more sensors, including for example forward facing cameras mounted behind the windshield of a vehicle, such as on or near the windshield. While these sensors are aligned and/or calibrated by the manufacturer during production of the vehicle whereby they are able to provide accurate driver assistance functionality, the sensors may need realignment or recalibration periodically, such as due to a mishap, such as a collision. In the case of a broken or cracked windshield, a sensor mounted on or near the windshield likewise may be required to be realigned or recalibrated when affixed to a new windshield. 
     SUMMARY OF THE INVENTION 
     The present invention provides a system and method for aligning a target to a vehicle for calibration of a sensor of the vehicle, and in particular for aligning a target to a sensor mounted on or near the windshield of the vehicle. 
     According to an aspect of the present invention, a system for aligning a target to an equipped vehicle for calibration of a sensor on the equipped vehicle includes a target adjustment stand having a base and a target mount moveably mounted on the target adjustment stand with the target mount configured to support a target, and the target adjustment stand further including actuators configured to selectively move the target mount relative to the base. The system further includes a pair of distance targets and a pair of distance sensors configured for use in measuring the distances between respective ones of aligned distance targets and sensors. The distance sensors and distance targets are arranged for measuring distances from the target adjustment stand to either side of a vehicle, with the measured distances used to adjust the position of the target mount. In a particular arrangement, the measured distances are from the target stand to either side of a pair of opposed wheel assemblies of the vehicle. 
     In accordance with a particular embodiment, the distance targets comprise a pair of wheel targets configured for positioning at opposed wheel assemblies of a vehicle, and the distance sensors are mounted to the target adjustment stand so as to be spaced apart from each other. A specific arrangement of the target adjustment stand includes an upright tower to which the target mount is movably affixed, with the actuators including a yaw actuator for selectively rotating the tower relative to the base and a vertical actuator for vertically moving the target mount. In a particular arrangement, the target mount is vertically and laterally moveable on the tower, and the tower is rotatably attached to the base so as to be rotatable about a vertical axis 
     The system may further include a computer having a display, such as a tablet computer, that is configured to display measured distances from the target adjustment stand to either side of the vehicle between respective ones of aligned distance targets and sensors. The yaw and/or vertical actuators are configured to be adjusted by an operator via one or more switches to adjust the position of the target mount based on the measured distances displayed on the computer. The target adjustment stand may also include a height sensor for measuring the vertical position of the target mount, with the computer configured to display the vertical position distance measured with the height sensor. The sensors may wirelessly transmit measured distance information to the computer. 
     In a further aspect, the target mount includes a light projector configured to project an indicating line, with the target mount being horizontally moveable and the indicating light being used to laterally position the target mount relative to the vehicle. The base of the target adjustment stand may include wheels for movement on a supporting surface, and may include a lock for fixing the position of the base relative to the surface. 
     According to a further aspect of the present invention, a method of aligning a target retained on a target adjustment stand to an equipped vehicle for calibration of a sensor on the equipped vehicle includes moving the target adjustment stand relative to the vehicle while measuring distances between the target adjustment stand and distance targets, rotating the target mount relative to the base while measuring distances between the target adjustment stand and the distance targets, centering the target mount to the vehicle by laterally moving the target mount as needed, such as by projecting a light from the target mount to center on the vehicle, placing a calibration target on the target mount, and moving the target mount vertically if needed. 
     A calibration routine, such as one specified and supplied by an OEM supplier of the vehicle, may then be run to calibrate the vehicle sensor to the vehicle. In the illustrated embodiments the sensor of the vehicle comprises a sensor mounted to, at or near the interior surface of a windshield of the vehicle. 
     The present invention for target alignment relative to a vehicle for calibration of a sensor on the equipped vehicle provides an efficient and effective system and method to align the target and sensor for calibration of the sensor, such as by way of an original equipment manufacturer (“OEM”) specified and provided calibration process. In the case of a sensor mounted on or near the windshield, such as a forward facing camera, the system and method are particularly useful for instances in which windshield replacement or repair are required, including due to cracked or broken windshields. The system and method may be used at a repair facility, including a body shop or windshield replacement facility. Upon aligning the target and sensor, such as in accordance with OEM requirements for the alignment, the calibration process may then be run whereby the proper operation of the sensor with respect to the vehicle may be provided. 
     These and other objects, advantages, purposes and features of this invention will become apparent upon review of the following specification in conjunction with the drawings. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1  is a perspective view of a vehicle target alignment system in accordance with the present invention arranged relative to a vehicle; 
         FIG. 2  is a front perspective view of the target adjustment stand or frame of  FIG. 1 ; 
         FIGS. 3 and 3A  are perspective views of wheel targets positioned adjacent a wheel assembly of the vehicle of  FIG. 1 ; 
         FIG. 3B  is a top view of the vehicle of  FIG. 1  illustrating wheel targets as shown in  FIG. 3  positioned adjacent the wheel assemblies on either side of the vehicle; 
         FIG. 4  is a perspective view of an alternative wheel target mounted to a wheel assembly of the vehicle of  FIG. 1 ; 
         FIG. 5  is a top view of the vehicle target alignment system of  FIG. 1 ; 
         FIG. 6  is a perspective view of the controller of the target adjustment stand of  FIG. 1 ; 
         FIGS. 7A and 7B  are perspective views illustrating the use of a light projector of target adjustment stand projecting a reference line for use in centering the target mount relative to the vehicle; 
         FIG. 7C  is a perspective view of the reference line projected from the target adjustment stand onto the front of a vehicle; 
         FIG. 8  is a perspective view of the target adjustment system of  FIG. 1  including a calibration target mounted to the target adjustment stand; 
         FIG. 9A  is a front perspective view of an alternative target adjustment stand in accordance with the present invention shown in a deployed orientation; 
         FIG. 9B  is a rear perspective view of the target adjustment stand of  FIG. 9A ; 
         FIG. 9C  is a front perspective view of the target adjustment stand of  FIG. 9A  shown in a storage orientation; 
         FIG. 9D  is a rear perspective view of the target adjustment stand of  FIG. 9A  shown in the storage orientation; 
         FIG. 9E  is a top elevation view of the target adjustment stand of  FIG. 9A ; 
         FIGS. 10A and 10B  are screen views of an operational program used to align the target adjustment stand relative to the vehicle illustrating longitudinal adjustment steps; 
         FIGS. 11A and 11B  are screen views of the operational program used to align the target adjustment stand relative to the vehicle illustrating yaw adjustment steps; 
         FIGS. 12A and 12B  are screen views of the operational program used to align the target adjustment stand relative to the vehicle illustrating target attachment and adjustment steps; and 
         FIG. 13  is a schematic illustration of an exemplary computer control program of the vehicle target alignment system in accordance with the present invention. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     The present invention will now be described with reference to the accompanying figures, wherein the numbered elements in the following written description correspond to like-numbered elements in the figures. With reference to  FIG. 1 , a vehicle target alignment system  20  in accordance with an embodiment of the present invention is shown for use in calibrating one or more sensors mounted to a vehicle  22 . System  20  includes a target adjustment stand or frame  24  that is configured to adjustably hold and position a calibration target  26  ( FIG. 8 ) relative to vehicle  22  when vehicle  22  and stand  24  are positioned relative to each other. In particular, distance targets or wheel targets  25   a ,  25   b  are positioned adjacent the front wheel assemblies  27  of vehicle  22  and an operator, as discussed in more detail below, aligns and positions the target  26  relative to a sensor  28  ( FIG. 3 ) mounted to vehicle  22  using distance sensors  30  and controller  32  on stand  24  whereby the sensor  28  may be appropriately calibrated to the vehicle  22 , such as by running an original equipment manufacturer (“OEM”) calibration routine for the specific vehicle  22  and sensor  28 . System  20  may thus be used in the calibration of a vehicle mounted advanced driver assistance system (“ADAS”) sensor, such as a forward facing camera sensor  28  of the vehicle  22  mounted on or near the vehicle windshield  34 . In particular, system  20  may be advantageously utilized in a repair facility when a windshield  34  must be replaced, such as after being damaged in a collision, broken by road debris, or the like. System  20  may also be used to verify and document that the proper calibration process is performed. 
     In the illustrated embodiment target adjustment, stand  24 , with reference to  FIGS. 1 and 2 , includes a base frame  44  that is movably supported by wheels  45  for longitudinal and lateral movement of stand  24  relative to vehicle  22 . Base frame  44  in turn includes locks for use in fixing stand  24  in a desired position on the floor surface, which are shown in the embodiment as a pair of floor anchors  43 , but may alternatively be caster locks or the like. A tower assembly  46  is mounted to base frame  44 , with tower assembly  46  including a vertically oriented member or tower  48  to which is mounted a target support assembly or frame  50  that is vertically moveable up and down along rails  52  on tower  48 . Target support frame  50  is additionally moveable laterally or horizontally side-to-side relative to tower  48 , such as by way of one or more horizontally mounted linear bearings  49  that are used to affix target support frame  50  to tower  48 , and includes a light projector  51  that, as discussed below, is used to laterally adjust the target support frame  50  relative to vehicle  22 . Target support frame  50  further includes a target mount  58  to which various targets  26  may be selectively affixed Stand  24  includes an actuator  54  for vertically moving target support assembly  50  up and down along rails  52 . Still further, tower assembly  46  is rotatably mounted to base frame  44  by way of a bearing assembly  56  disposed between the tower  48  and base frame  44  so as to be able to pivot about a vertical or Z-axis, with tower assembly  48  being pivoted by actuator  64 . It should be appreciated, however, that in other embodiments alternative arrangements and configurations of actuators for movement of tower assembly  46  in the various axes relative to base frame  44  may be employed, as well as alternative controllers for the various operations discussed herein. The actuator for rotating tower assembly  46  may, for example, be disposed beneath base frame  44 . As further understood from  FIGS. 1 and 2 , stand  24  includes a cross bar or member  63  mounted to tower  48 , with cross member  63  supporting the pair of distance sensors  30  at opposed ends of cross member  63 . Cross member  63  thus forms a pair of arms extending in opposed directions from tower  48  to which sensors  30  are mounted. In the illustrated distance sensors  30  are configured as time-of-flight (“ToF”) sensors, although alternative distance sensors may be employed. 
     As discussed in more detail below, the actuators  54 ,  64  are selectively controllable for movement by an operator using controller  32 , where system  20  further includes a computer device having a display  65  ( FIGS. 10A-12B ) in communication with distance sensors  30  for providing information to the operator regarding the position of stand  24  relative to vehicle  22 . In the illustrated embodiment, display  65  is part of a portable computer  67 , such as a tablet computer or laptop. Alternatively, however, the display  65  may be configured as part of controller  32  or a separate computer device. 
     System  20  is used by initially driving vehicle  22  into an initial or start position, such as by being pulled into a bay of a repair facility, with the wheel assemblies  27  of vehicle  22  being oriented into a straight position relative to the longitudinal axis of vehicle  22 . With reference to  FIGS. 3, 3A and 3B , an operator then places a separate wheel target  25   a ,  25   b  adjacent each of the front wheel assemblies  27  of vehicle  22 . In the illustrated embodiment, each wheel target  25   a ,  25   b  includes a frame  68  and a planar panel  69 , where frame  68  is constructed to rest on the floor surface upon which vehicle  22  is positioned with panel  69  being perpendicular to the floor surface. Frame  68  further includes a longitudinal frame extension member  71  that is oriented to be perpendicular to panel  69  and is configured to be positioned adjacent the tire and/or wheel of the wheel assembly  27  so as to square wheel targets  25   a ,  25   b  relative to the wheel assemblies  27 , and thereby square wheel targets  25   a ,  25   b  with the longitudinal axis of vehicle  22 . In the illustrated embodiment, frames  68  additionally include light projectors  73 , such as lasers, for projecting a vertically oriented planar indicating light  74  (see  FIG. 3A ) to aid in aligning wheel targets  25   a ,  25   b  with the center of wheel assemblies  27 , where the indicating light  74  is coplanar with the panel  69 . As understood from  FIG. 3A , wheel targets  25   a ,  25   b  are positioned until the indicating light bisects the center hub  75  of wheel assemblies  27  by an indicating line  74   a  formed by indicating light  74  on hub  75 . The operator may, for example, visually center the indicating line  74   a  formed by indicating light  74  on the center hub  75 . In this way, wheel targets  25   a ,  25   b  are positioned in known orientations both laterally and longitudinally relative to vehicle  22 . It should be appreciated that alternative wheel targets may be employed within the scope of the present invention, including, for example, wheel targets that attach to wheel assemblies  27  rather than engage by contact with wheel assemblies  27  in the illustrated embodiment. Still further, alternative wheel targets may include alternative members for contacting wheel assemblies  27 . 
     For example, an alternative wheel target  125  is shown in  FIG. 4  comprising a wheel clamp  100  supporting a panel  169 , where when clamp  100  is secured to the wheel assembly  27  the panel  169  is perpendicular to the wheel assembly  27  and is centrally aligned in a planar manner with the rotational axis of the wheel assembly  27 . In the illustrated embodiment wheel clamp  100  includes multiple adjustable arms  101  having extendable and retractable projection arms  102  to which are mounted claws  103 , where claws  103  are configured for engaging to the wheel flange  104  of the wheel  105  of the wheel assembly  27 . Also provided are optional retention arms  106  that engage with the tire  107  of the wheel assembly  27 . In use, claws  103  may be disposed about the wheel flange  104  with a spacing of approximately 120 degrees, with projection arms  102  being drawn in, such as by the rotatable handle  108  shown, to securely fix the clamp  100  to the wheel flange  104  of the wheel  105  of the wheel assembly  27 . When so mounted, clamps  100  are co-planar with a plane defined by the wheel  105  and are centered on wheel  105 , where wheel  105  is mounted to the hub of the axle, which establishes the axis of rotation such that the clamps  100  are mounted about the axis of rotation of wheel  105 . The clamps  100  further include a central hub  111 , which when mounted to wheel  105  is centered on the wheel  105  and is aligned about the axis of rotation of wheel  105 . Central hub  111  in turn includes a post or shaft  109  and a bearing assembly or mount or block  110  mounted coaxially to shaft  109  so as to be disposed perpendicularly to shaft  109  and is able to rotate on shaft  109 . Panel  169  in turn is mounted to bearing block  110 . Bearing block  110  pivots on shaft  109  such that due to gravity panel  169  will naturally rotate into a vertical orientation. 
     With reference to  FIG. 5 , once the wheel targets  25   a ,  25   b  (or  125 ) are in place, an operator may then position stand  24  relative to vehicle  22  to set the longitudinal distance of stand  24  relative to vehicle  22 . As understood from  FIGS. 1 and 5 , cross member  63  spans the width of vehicle  22  so as to position distance sensors  30  in relation to wheel targets  25   a ,  25   b . In the illustrated embodiment, cross member  63  is disposed at a vertical height on tower  48  whereby distance sensors  30  are aligned with panels  69  of wheel targets  25   a ,  25   b . Sensors  30  are thereby configured to measure distances to each of wheel targets  25   a ,  25   b  by, for example, projecting a light source signal at panels  69  and receiving the reflected signal back. As discussed in more detail below, operator receives via display  65  information regarding the distance of stand  24  from vehicle  22  as measured by distance sensors  30 , as well as information regarding the desired distance to which stand  24  is to be positioned, such as based on the particular make, model and year of vehicle  22 . The operator then manually adjusts the stand  24  longitudinally relative to vehicle  22  via wheels  45  of base frame  44  based on the feedback from the distance measurements obtained with the distance sensors  30 . Upon obtaining a desired orientation of stand  24  as specified on the display  65 , operator is then able to fix base frame  44  to the floor surface by way of locks  43 . 
     The operator may then more precisely or fine adjust the yaw position of tower assembly  46  by way of actuator  64  that rotates tower assembly  46  about the vertical axis. As shown in  FIG. 6 , controller  32  includes a switch  76  for selectively activating actuator  64  to rotate in either a clockwise or counterclockwise direction. In particular, based on the two distance sensors  30  and the feedback information on the distance measured therewith provided to the operator on display  65 , the operator may rotate the tower assembly  46  so that the two distance sensors  30  are equidistant from the respective wheel targets  25   a ,  25   b  due to cross bar  63  being mounted to tower assembly  46  for rotation therewith. In this way the tower assembly  46  is squared to the longitudinal axis of vehicle  22  at the desired longitudinal distance. 
     Upon establishing the longitudinal position of stand  24 , the operator may then set the lateral orientation of the target support frame  50  and accompanying target mount  58  relative to vehicle  22 , as understood from  FIGS. 7A-7C . Light projector  51  is turned on and is configured to project a vertically oriented light plane  77 , where light projector  51  may be configured as a laser or other type of light projector. As noted, target support frame  50  is laterally moveable from side-to-side by way of linear bearing  49 . The operator may then laterally move the target support frame  50  such as by manually sliding the frame  50  until the projected light  77  from light projector  51  is centered on vehicle  22 , which as understood from  FIG. 7C  may be established by centering the projected light  77  on a center hood emblem or badge  79  on vehicle  22 , such as on the front bumper or fascia of vehicle  22 . In the illustrated embodiment the operator may visually center the projected light  77  on the badge  79  while manually sliding target support frame  50  from side-to-side, but may alternatively employ a visual gauge or the like, or may be powered for side-to-side motion by an actuator. Upon obtaining the desired lateral center position, the target support frame  50  may be locked relative to tower  48  such as by way of locks (not shown) on or associated with linear bearing  49  to prevent further movement, where the locks may be configured as setscrews, clamps or the like. 
     With reference to  FIG. 8 , the operator may then mount the required calibration target  26  to the target mount  58  and position the target support frame  50  and associated target mount  58  into the appropriate vertical position. It should be appreciated that multiple calibration targets  26  may be needed for various makes, models and years of vehicles, and associated sensors, and that the particular calibration target  26  to be used in calibrating a given vehicle sensor  28  will depend on the particular sensor  28  and be selectable based on, for example, the make, model and year of vehicle  22 , as well as potentially based on particular features, options or packages on vehicle  22 . As discussed in more detail below, system  20  is thus configured to provide instructions to the operator via display  65  as to which target  26  to use, as well as includes a verification program or system to ensure that the correct calibration target  26  is used for the given vehicle  22  and sensor  28  at issue. For example, in the illustrated embodiment, calibration targets  26  are provided with RFID tags  59  and display  65  not only prompts the operator as to which calibration target  26  to use, but the system  20  via a computer program, such as within controller  32  or computing device  67 , requires the operator to scan the RFID tag of the calibration target  26  to confirm selection of the proper target  26 . The operator, for example, may scan the RFID tag with a separate scanner, or with the computing device  67 . 
     Controller  32 , as shown in  FIG. 6 , additionally includes one or more vertical positioning switches  81 , which in the illustrated embodiment comprise an up button and a down button for controlling actuator  54 . In the embodiment shown, stand  24  is constructed to include a height sensor  82  ( FIG. 5 ) associated with target support frame  50  and thus with the target mount  58 . For example, the height sensor  82  may comprise a string potentiometer that is calibrated, or may be constructed as another known distance sensors whereby the vertical adjustment and positioning of target mount  58  is thus monitored. The vertical orientation of target mount  58  is thus known and calibration targets  26  are likewise constructed so as to position the target indicia depicted on calibration targets  26  in a particular orientation that is known or taken into account by system  20 . It should be appreciated that alternative techniques may be employed for monitoring the vertical height. For example, based on a controlled motion and known positioning of actuator  54 . Accordingly, display  65  may likewise provide vertical position information to the operator to instruct the operator where to vertically position the target mount  58  whereby the operator may then adjust the target mount  58  up and down via switch  81  to the desired vertical position, such as may be specified or required by an OEM calibration process. 
     Upon positioning the calibration target  26  into the specified position with respect to the longitudinal distance from vehicle  22 , the yaw about the vertical axis of tower  48 , and the vertical height along tower  48 , operator may then initiate a calibration sequence for calibrating the sensor  28  to the vehicle  22  using the positioned calibration target  26 . This may involve, for example, an OEM specified and provided calibration process. 
     An alternative target adjustment stand or frame  124  in accordance with the present invention is illustrated in  FIGS. 9A-9E , where stand  124  shares similar features as stand  24  discussed above. Accordingly, the similar features of stand  124  are marked with like reference numbers as used with stand  24 , but with “100” added to the reference numbers of stand  124 . Due to the similarities, not all of the features and components of stand  124  are discussed herein. 
     Target adjustment stand  124  is similarly configured to adjustably hold and position a calibration target  26  relative to a vehicle  22 , where stand  124  is positioned relative to vehicle  22  using wheel targets  25   a ,  25   b  or  125  so as to align and position the target  26  relative to a sensor  28  mounted to the vehicle  22  using distance sensors  130  and controller  132  on stand  124  whereby the sensor  28  may be appropriately calibrated to the vehicle  22 . 
     Stand  124  includes a base frame  144  that is movably supported by wheels  145  and includes locks or anchors  143 . A tower assembly  146  is mounted to base frame  144 , with tower assembly  146  including a vertically oriented base or first tower member  148   a  to which is mounted a vertically extendable second tower or extension member  148   b , where extension member  148   b  is slidable on rails  147  ( FIG. 9C ) of base member  148   a . In turn, a target support assembly or frame  150  is mounted to extension member  148   b , where assembly  150  is vertically moveable up and down along rails  152  on member  148   b . Target support frame  150  includes a target mount  158  that is moveable laterally or horizontally side-to-side relative to tower  146 , such as by way of one or more horizontally mounted linear bearings  149  on rail  149   a . Still further, a light projector  151  is provided at target mount  158  that is used to laterally adjust the target mount  158  relative to vehicle  22 , where projector  151  projects a vertical line in like manner to projector  51  discussed above that may be used to center target mount  158  on vehicle  22 . Target mount  158  is provided with an additional light projector  153  that projects a horizontal line, such as a laser light or the like. Light projector  153  may be used to project a horizontal indicating light on vehicle  22  for use in vertically orienting target mount  158  relative to a feature or component on vehicle  22 . For example, as understood from  FIG. 7C , a horizontal indicating light  177   a  may be positioned relative to a radar module  128   a  of vehicle  22  and thereby set the vertical height of target mount  158 . Still further, as also shown in  FIG. 9A , target mount  158  may additionally include a camera  155  for taking images of the calibration setup and arrangement relative to the vehicle  22 , such as for documenting compliance with the calibration procedures, where such images may be saved to and/or stored on computer  167 . 
     Various targets  26  may be selectively affixed to the target mount  158  of target support assembly  150 , such as by hooking projections on the targets  26  onto receptacles of the target mount  158 , or the like. Stand  124  includes an actuator  154  for vertically moving extension member  148   b  up and down relative to base member  148   a , as well as for vertically moving target support assembly  150  up and down along rails  152 . Tower assembly  146  is also rotatably mounted to base frame  144  by way of a bearing assembly  156  disposed between the tower  148  and base frame  144  so as to be able to pivot about the vertical or Z-axis, with tower assembly  148  being pivoted by another actuator disposed beneath base frame  144 . Stand  124  also includes a pair of cross bars or members or arms  163   a ,  163   b  mounted to tower  148 , with each arm  163   a ,  163   b  supporting a distance sensor  130  at an opposed end of the respective arm  163   a ,  163   b.    
     The actuators of stand  124  for rotating tower assembly  146  and for vertically adjusting the height of target support frame  150  are selectively controllable for movement by an operator  112  using controller  132 , where the system further includes a tablet computer device  167  having a display  165  and being in communication with distance sensors  130  for providing information to the operator  112  regarding the position of stand  124  relative to vehicle  22 . As shown in the embodiment of  FIGS. 9A-9D , controller  132  comprises a handheld pendant controller for use by the operator  112  with buttons for controlling the actuators of stand  124 . In like manner to stand  24 , the target mount  158  is manually moveable along bearings  149 , but may alternatively employ an actuator for powered movement via controller  132 . Controller  132  may be wireless device or may be wired to stand  124 . 
     Stand  124  additionally includes a platform or desktop surface  200  on which computer  167  are mounted via holder  202 , and where controller  132  may be mounted or placed when not in use. Platform  200  further includes handles  204  by which operator  112  can grasp when moving stand  124 . 
     Of particular note is that stand  124  is collapsible into a storage position ( FIGS. 9C and 9D ) when stand  124  is not in use. To this end, each of the arms  163   a ,  163   b  are pivotable between an extended horizontal position and a retracted or folded position in which the arms  163   a ,  163   b  are vertically oriented. Each arm  163   a ,  163   b  is pivotably mounted to and retained within a respective brace  206   a ,  206   b , where the braces  206   a ,  206   b  are attached to the tower  148 . Retention screws  208  are used to selectively secure the arms  163   a ,  163   b  in the desired retracted or extended positions. Still further, target support assembly  150  is additionally rotatable relative to tower  148  whereby it may be set in a horizontal orientation for use and rotated into a vertical orientation for storage. This includes the rail  149   a  and target mount  158  being rotably attached to the tower  148 , such as by shaft  210  ( FIG. 9E ). 
     Referring now to  FIGS. 10A-12B , an exemplary computing device  67  such as a tablet computer having a display  65  is illustrated for use in providing instructions and information to the operator for the calibration of sensor  28 , including to position the calibration target  26  as discussed above. As noted, the positioning of stand  24 , and selection and use of a calibration target  26  will depend on the particulars of the vehicle  22  and sensor  28  at issue. Accordingly, in an initial step information regarding the vehicle  22  is entered into system  20 , such as by way of the operator entering the data into computer  67 , which may be done by manual entry, scanning, or by reading data from an electronic control unit (“ECU”) of vehicle  22 , or other such data acquisition operation. Based on the identified vehicle  22  and sensor  28  requiring calibration, system  20  may then provide the operator with particular information and instructions required. It should be appreciated that system  20  then operates based on the known configuration, orientations and dimensions of the vehicle  22  entered by the operator and the known configuration, orientations and dimensions of stand  24 . This includes, for example, the known distances from the center of the hubs  75  to the sensor  28  as installed on the windshield  34  of vehicle  22 , the known height of the sensor  28  relative to the floor surface. This further includes the known position, orientation and dimensions of the distance sensors  30  and target mount  58  on stand  24 , as well as the configuration of the calibration targets  26  themselves. 
     System  20  may, for example, provide the display screen  65  illustrated in  FIG. 10A  after identification of vehicle  22 , and after the operator has placed the wheel targets  25   a ,  25   b  as shown in  FIGS. 3-4  and has initially oriented stand  24  as shown in  FIG. 5  such that distance information from sensors  30  is provided. As shown on the display screen  65 , a displayed image may be included, such as the overhead image shown, of the target stand and vehicle for aiding the operator in setting up the system  20 . As there shown, a desired longitudinal distance  83  is provided as an instruction to the operator, along with the actual longitudinal distances  85   a ,  85   b  for each of the two wheel targets  25   a ,  25   b  as measured via distance sensors  30 . The operator is able to manually adjust stand  24  to an acceptable initial or rough position while monitoring the actual longitudinal distances  85   a ,  85   b  on display screen  65 . The acceptable initial position may be based on predetermined limits within the program of system  20 , such as a predetermined plus or minus range for each of the actual longitudinal distances  85   a ,  85   b  from the desired longitudinal distance  83 .  FIG. 10B  illustrates display screen  65  upon the operator positioning stand  24  into an acceptable initial position. For example, as shown, the program of system  20  may notify the operator when stand  24  is in an acceptable initial longitudinal position, such as by providing a signal to the operator via the display screen  65 , where in the illustrated embodiment the signal is configured as a change in the appearance of the display screen  65 . Although illustrated as a change in color, alternative notifications may be provided, such as a popup display or notification. Upon obtaining this acceptable initial position, the operator may hit the next button  87  on display screen  65 , which in the illustrated embodiment is a touch screen. 
     Next, the operator may adjust the yaw of tower assembly  46  relative to vehicle  22  by rotating the tower assembly  46  about the vertical axis by way of switch  76  and actuator  64  while again monitoring the actual longitudinal distances  85   a ,  85   b . This squaring step is illustrated in  FIGS. 11A and 11B . Upon rotating the tower assembly  46  such that the actual longitudinal distances  85   a ,  85   b  are within a predetermined range or limit of each other and both within a predetermined range or limit of the desired longitudinal distance  83 , the program of system  20  may again provide a signal to the operator via the display screen  65 , such as by a change in the appearance of the display screen  65  or a pop-up notification. The operator may then hit the next button  87 . 
     The operator may then proceed to laterally adjust the position of the target mount  58  by manually sliding the target mount while monitoring the projected light  77  relative to the center of the vehicle  22 , as discussed above. The instructions for this procedure may be provided by the program of system  20  and appear on the display screen  65 , with the operator again hitting the next button  87  upon properly centering the target mount  58  and locking it in place, as discussed above. 
     The program of system  20  may then instruct the operator which calibration target  26  to select for mounting to the target mount  58 , as illustrated in  FIGS. 12A and 12B . As discussed above, the system  20  may require confirmation of selection of the correct calibration target  26 , such as by way of RFID tag reading confirmation. The program of system  20  may then instruct the operator as to the correct vertical height to which the target mount  58  is to be positioned by way of the actuator  54  and switches  81 . The desired and actual vertical heights may be displayed on display screen  65 , where the actual height may be obtained via the height sensor  82  discussed above, and/or based on the known dimensions of stand  24  and the controlled movement of actuator  54 . A signal may again be provided to the operator upon obtaining the desired height, with the operator subsequently hitting the next button  87 . The program of system  20  may then instruct the operator to run the calibration sequence. 
     In the illustrated embodiment information regarding the actual longitudinal distances  85   a ,  85   b  from distance sensors  30  and information from the vertical height of target mount  58  from height sensor  82  may be provided to portable computer  67 , such as via a wireless connection. 
     An exemplary embodiment of a control program  89  of system  20  is disclosed in  FIG. 13 , such as may be run on portable computer device a separate computer. As shown in  FIG. 13 , program  89  includes the steps of vehicle identification  91 , initial longitudinal stand positioning  93 , yaw adjustment  95 , lateral centering  97 , calibration target attachment  99 , vertical calibration target positioning  101 , and vehicle sensor calibration  103 . 
     It should be appreciated that alternative structures, techniques, features and methods may be employed for the positioning of the calibration target  26  relative to the vehicle sensor  28  within the scope of the present invention. For example, in the illustrated embodiment portable computer  67  does not control actuators  54  or  64 . In an alternative embodiment, however, an operator may be able to control actuators  54  and/or  64  via portable computer  67  via controller  32 . Still further, system  20  may be able to perform some operations in an automated manner without input from the operator, such as adjusting the yaw of tower assembly  46  or setting the vertical height of target mount  58 . 
     Still further, the disclosed system and method may be used with alternatively configured target adjustment stands, including for example, instead of distance sensors  30  being mounted to stand  24  as shown in the illustrated embodiment, in an alternative configuration distance sensors may be positioned at, adjacent or on wheel assemblies  27  with spaced apart distance targets being located on stand. Further changes and modifications in the specifically described embodiments can be carried out without departing from the principles of the present invention which is intended to be limited only by the scope of the appended claims, as interpreted according to the principles of patent law including the doctrine of equivalents.