JP7566752B2 - Robotic Target Alignment for Vehicle Sensor Calibration - Google Patents

Description

The present invention is directed to vehicle alignment/calibration methods and systems, and in particular to methods and systems for aligning a vehicle and its sensors to one or more autonomously positioned alignment/calibration targets.

The use of radar, imaging systems and other sensors, such as LIDAR, ultrasonic and infrared (IR) sensors, to determine the range, speed and angle (elevation or azimuth) of objects in an environment is important in many automotive safety systems, such as advanced driver assistance systems (ADAS) for vehicles. Conventional ADAS systems use one or more sensors. These sensors are aligned and/or calibrated by the manufacturer on the assembly line (or at another facility at another time), but the sensors may need to be periodically realigned or recalibrated due to, for example, the effects of wear and tear or misalignment through driving conditions or mishaps such as accidents. Furthermore, such ADAS systems may include one or more subsystems, such as adaptive cruise control (ACC), lane departure warning (LDW), parking assistance and/or a rearview camera. Each of the subsystems may require individual realignment or recalibration periodically.

The present invention provides a method and system for aligning and/or calibrating sensors mounted on a vehicle by aligning the vehicle and thus the sensors mounted on the vehicle with one or more robotically positioned calibration targets. In positioning the one or more calibration targets, a robot selects and positions an appropriate target for alignment/calibration of one or more sensors of the vehicle's ADAS system. The robot positions the appropriate target according to a known reference position. The vehicle is also positioned and centered relative to the known reference position. With the vehicle and calibration targets positioned and centered relative to the known reference positions, the vehicle sensors are calibrated, for example, via an original equipment manufacturer ("OEM") calibration process. In yet another embodiment, a rear thrust angle for the vehicle can be determined. This rear thrust angle can be used to adjust the position of the robotically positioned targets.

According to an aspect of the invention, a robotic system for aligning a target with respect to an equipped vehicle for calibration of the equipped vehicle's sensors includes a stationary vehicle support stand and a robotic manipulator that is longitudinally movable toward and away from the vehicle support stand on which the equipped vehicle is stationary positioned at an established known position for calibration of the equipped vehicle's sensors. The robotic manipulator includes a multi-axis robotic arm that holds the target. The robotic manipulator is configured to position the target in a calibration position with respect to the equipped vehicle's sensors by longitudinal movement of the robotic manipulator relative to the vehicle support stand and by movement of the robotic arm based on the established known position of the equipped vehicle on the vehicle support stand, such that the target can be used to calibrate the sensors.

According to a particular embodiment, the robotic arm includes an end effector configured to selectively grasp a target from a plurality of targets, and the robotic manipulator is attached to a base that is longitudinally movable along a track in a floor support surface. The track includes a rail disposed vertically lower than the floor support surface along which the base is movable. Alternatively, the target may be an electronic digital display device configured to display or show different patterns, grids, etc. on a screen depending on the make and model of the vehicle and the sensor being calibrated. A controller of the system causes the target pattern to be displayed based on the vehicle being tested.

In yet a further embodiment, the vehicle support stand includes a plurality of locator arms that are extendable and retractable and configured to press against a tire and wheel assembly of an installed vehicle on the vehicle support stand, e.g., to orient the installed vehicle to an established known position. The locator arms include a set of forward and rearward opposing arms that are configured to extend evenly in opposite directions from each other, e.g., to center the installed vehicle on the vehicle support stand.

According to a further aspect, the vehicle support stand includes a movable front tire support and a movable rear tire support. Opposing sets of tires of the mounted vehicle are disposed on the movable front tire support and the movable rear tire support. The front tire support and/or the rear tire support may be configured as rollers. The rotational axes of the rollers may be aligned with the longitudinal axis of the mounted vehicle. In a particular embodiment, the front tire supports each include two sets of rollers. The two sets of rollers are angled in a V-shaped configuration to position the mounted vehicle. The rear tire supports each may include at least one set of rollers oriented generally horizontally.

According to yet another aspect of the invention, the vehicle support stand may include a forward centering device and/or a rear centering device that is positioned under the equipped vehicle when the equipped vehicle is placed on the vehicle support stand. The forward and rear centering devices include a pair of locator arms that are configured to synchronously expand outwardly to engage the inside of the tire and wheel assembly of the equipped vehicle.

In another aspect, the vehicle support stand includes a pair of forward non-contact wheel alignment sensors and/or a rear non-contact wheel alignment sensor disposed adjacent opposing tires and wheel assemblies of the respective equipped vehicle when disposed on the vehicle support stand. The non-contact wheel alignment sensors are operable to determine vehicle orientation information to determine an established known position of the equipped vehicle for use in positioning the target in the calibration position.

According to a further aspect of the invention, a method for robotically aligning a target with an equipped vehicle for calibration of a sensor of the equipped vehicle includes guiding the equipped vehicle onto a stationary vehicle support stand, where the equipped vehicle includes a sensor and is stationarily positioned on the vehicle support stand, and moving a target held by a robotic manipulator to a calibration position for calibration of the sensor based on an established known position of the equipped vehicle on the vehicle support stand. The robotic manipulator includes a multi-axis robotic arm that is longitudinally movable relative to a longitudinal axis of the equipped vehicle on the vehicle support stand and configured to hold the target. The method may further include guiding the vehicle from the vehicle support stand, where the vehicle may be guided by moving the vehicle onto the vehicle support stand and out of the vehicle stand. In certain embodiments, the method requires an operator to move the vehicle onto the support stand and out of the support stand after calibration of the vehicle sensor. The vehicle is moved across the track of the robotic manipulator.

According to certain embodiments, the robotic manipulator includes an end effector disposed on a robotic arm configured to selectively grasp a target from a plurality of targets, the robotic manipulator being attached to a base that is longitudinally movable along a track on a floor support surface. The vehicle support stand may include a plurality of extendable and retractable locator arms. The plurality of extendable and retractable locator arms are configured to press against a tire and wheel assembly of the equipped vehicle to orient the equipped vehicle on the vehicle support stand, such as to orient the equipped vehicle to an established known location. The stand also includes movable front and rear tire supports. Opposed sets of tires of the equipped vehicle are disposed on the movable front and rear tire supports. The equipped vehicle may be moved onto the support stand in a first direction and, after calibration of the sensor, moved out of the support stand by being moved in the same first direction across the floor support surface. The method may include moving the robotic manipulator longitudinally away from the vehicle on the support stand to enable the equipped vehicle to be moved out of the support stand in the first direction. Alternatively, the vehicle is equipped to be moved out of the support stand in a first direction and then in the opposite direction after calibration of the sensor.

The method may further include a pair of front and/or rear non-contact wheel alignment sensors positioned adjacent opposing tires and wheel assemblies of each equipped vehicle when placed on the vehicle support stand. The non-contact wheel alignment sensors are operable to determine vehicle orientation information to determine an established known position of the equipped vehicle for use in positioning the target at the calibration position.

The present invention provides a system and method for accurately positioning a calibration target relative to a vehicle's sensor and calibrating the sensor, e.g., in accordance with OEM standards. Accurate positioning and calibration of the sensor therefore helps optimize the performance of the sensor, thus enabling the sensor to perform its ADAS function. These and other objects, advantages, purposes and features of the present invention will become apparent upon review of the following specification in conjunction with the drawings.

FIG. 1 is a perspective view of a robotic target alignment system for calibration of vehicle sensors in accordance with the present invention; FIG. 2 is a perspective end view of the moveable robot target holder of FIG. FIG. 2 is a front view of an exemplary target such as that shown in FIG. FIG. 2 is a top view of the vehicle centering system of the target alignment system of FIG. FIG. 4 is a perspective view of the vehicle centering system of FIG. 3. FIG. 4 is a side perspective view of the front wheel assembly support of the vehicle centering system of FIG. FIG. 4 is a bottom view of the front wheel assembly support of the vehicle centering system of FIG. FIG. 4 is a bottom view of the rear wheel assembly support of the vehicle centering system of FIG. FIG. 2 is a perspective view of another robotic target alignment system for calibration of vehicle sensors in accordance with the present invention. FIG. 9 is a top view of the robotic target alignment system of FIG. FIG. 9 is a side perspective view of the non-contact wheel alignment sensor of the robotic target alignment system of FIG. 8 positioned about the left front wheel assembly of the vehicle. FIG. 9 is a partial perspective view of a portion of the robotic target alignment system of FIG. 8 showing a non-contact wheel alignment sensor and a locator arm adjacent a roller for receiving a wheel assembly of a vehicle. FIG. 13 is a top elevation view of the robot in two calibration positions relative to the calibration master. FIG. 2 is a schematic diagram of remote process operation of a robotic target alignment system in accordance with the present invention. 1 illustrates steps for a method for aligning a calibration target and performing calibration of a vehicle sensor in accordance with an aspect of the present invention. FIG. 1 is a top view of an alternative tire support for use in connection with the present invention constructed as a floating plate. 1 is a perspective view of an alternative vehicle support stand for use in connection with the present invention; FIG.

The invention will now be described with reference to the accompanying drawings. Numbered elements in the written description below correspond to similarly numbered elements in the drawings.

FIG. 1 illustrates an exemplary robotic target alignment and ADAS sensor calibration system 30 for use in calibrating one or more sensors 32 of a vehicle 34. A target or target panel 36 is held by a mobile robot or robotic manipulator 38 positioned in front of the vehicle 34. As discussed in detail below, the target 36 is positioned relative to the vehicle 34 to calibrate/align one or more sensors 32 of the vehicle 34. The target is adjustably moved via the robotic manipulator 38 to a known orientation or calibration position relative to the vehicle 34, such as relative to the vehicle's sensors 32. For example, upon orienting the vehicle 34 to a known position, which may include determining the orientation of the vehicle 34, the robot 38 may move the target 36 to align the target 36 with one or more sensors 32 of the vehicle 34. As discussed herein, the sensor to be calibrated is one of one or more subsystems of an exemplary advanced driver assistance system (ADAS) of the vehicle. The sensor 32 may thus be a LIDAR, ultrasonic and infrared ("IR") sensor of an ADAS system, including radar sensors for adaptive cruise control ("ACC"), imaging systems, camera sensors for lane departure warning ("LDW") and other ADAS camera sensors located around the vehicle, as well as other sensors, such as forward-facing cameras, mounted inside the vehicle or mounted outside. The target 36 is supported by a robot 38 constructed for calibrating such sensors, such as a grid, pattern, trihedron, etc. Once the target 36 is aligned with the sensor 32 of the vehicle 34, a calibration routine is performed. The target 36 is then used to calibrate or align the sensor. As used herein, references to calibrating a sensor include aligning the sensor with a calibration target.

1, the system 30 includes a computer system or controller 40 and a vehicle support stand 42. The vehicle 34 is held stationary on the vehicle support stand 42, whereby the vehicle 34 is oriented longitudinally with the robotic target positioning system 44. As can be seen from FIG. 2, the target positioning system 44 includes a multi-axis robot 38 having multiple joints attached to a movable base 46. The base 46 is configured to move longitudinally along a track 48 relative to the vehicle 34. In particular, the base 46 is mounted on a longitudinally extending rail 50, whereby the base 46 is movable toward and away from the vehicle 34 via an electric motor 52 that receives control signals via the controller 40. In the illustrated embodiment, the track 48 is configured such that the base 46, and thus the robot 38, is moved approximately 1 meter to 20 meters from the vehicle 34 when the vehicle 34 is placed on the stand 42, but is preferably movable from approximately 1 meter to approximately 7 to 10 meters. As shown, the track 48 is positioned in front of or ahead of the vehicle 34. In the illustrated embodiment, the track 48 is centrally aligned with the support stand 42 such that the longitudinal axis of the vehicle 34 on the support stand 42 is aligned with the longitudinal axis of the track 48. Alternatively, the track 48 may be placed laterally on either side of the structure shown in FIG. 1. The base 46 of the robotic manipulator 38 may conventionally include one or more load cells configured to detect and/or measure impact forces to determine if the robotic manipulator 38 comes into contact with something while guiding the target 36 or while moving along the track 48. For example, the robotic manipulator 38 may be configured to stop movement should the robotic manipulator 38 come into contact with an object or person. As can be seen from FIG. 1, various plates 54 may be used to cover or partially cover gaps along or adjacent to the track 48. Thus, the vehicle 34 may be guided onto or off the support stand 42, including onto the track 48 of the target positioning system 44, for example, by moving the vehicle 34. For example, the vehicle 34 may be moved onto the support stand 42. Once calibration of a given sensor 32 is complete, the vehicle 34 may be moved in the same direction off the support stand 42. The vehicle 34 is moved across the track 48. Alternatively, once the sensor 32 is calibrated, the vehicle 34 may be moved in the opposite direction off the support stand 42. For example, as understood with respect to the orientation of the vehicle 34 in FIG. 1, the vehicle may be moved forward onto the support stand 42, and then moved in the opposite direction off the support stand 42 once the sensor 32 is calibrated.

The robot 38 includes a multi-axis arm 38a with many segments and joints, and includes an end effector or tool changer or target gripper 39 at the end of the arm 38a for use in gripping the desired target 36. Multiple targets may be placed in a holder 49 adjacent to the track 48 within reach of the robot 38. For example, the holder 49 may include different types of targets for different types of sensors and for different types of vehicle makes and models. Thus, upon selecting the desired target for a particular vehicle under test, the robot 38 positions the target in the appropriate position for calibration of the particular ADAS sensor to be calibrated. As mentioned, various targets including panels with grids, patterns, trihedrons, or other known targets for use in calibrating sensors may be held by the tool 39. The targets may include, for example, targets for visual cameras, night vision systems, laser scanner targets, ultrasonic sensors for aligning or calibrating ACC (adjacent distance control) sensors, LDW (lane departure warning) sensors, and night vision vehicle sensors. In some aspects of the invention, different target frames may be individually configured for different sensors, e.g., ACC, LDW, and night vision sensors. An exemplary pattern or grid is disclosed on the target 36 in connection with FIG. 2A. However, as discussed herein, it should be appreciated that otherwise configured targets, including alternative patterns, grids, and configurations of targets, may be used within the scope of the invention. Alternatively, the target 36 may be an electronic digital display device configured to display or show different patterns, grids, etc. on the screen depending on the make and model of the vehicle and the sensor being calibrated. The controller 40 is operable to cause the correct target pattern to be displayed based on the vehicle 34 and sensor 32 being calibrated.

The vehicle support stand 42 includes a front wheel support and centering assembly 56 and a rear wheel support and centering assembly 58. The front wheel support and centering assembly 56 and the rear wheel support and centering assembly 58 are mounted on the vehicle 34 to position or orient the vehicle 34. In the orientation of FIG. 1, the front wheel assembly 60 of the vehicle 34 rests on the front wheel support and centering assembly 56 and the rear wheel assembly 62 of the vehicle 34 rests on the rear wheel support and centering assembly 58. As will be discussed in more detail below, the assemblies 56, 58 allow lateral movement of the vehicle 34 for purposes of positioning the vehicle 34. In addition, the front wheel support and centering assembly 56 also prevents the vehicle 34 from moving longitudinally. For example, it should be understood that if the desired vehicle can be oriented rearwardly toward the target positioning system 44 for calibration of one or more rearwardly oriented vehicle sensors, the rear wheel assembly 62 of the vehicle 34 is disposed on the front wheel support assembly 56.

With reference to Figures 3-6, the front wheel support and centering assembly 56 includes oppositely disposed tire supports 64a, 64b positioned on opposite sides of a front vehicle centering device 66. The tire supports 64a, 64b are configured to receive opposing tires of a pair of tires of a wheel assembly of the vehicle 34, such as the front wheel assembly 60 shown in Figure 1. The tire supports 64a, 64b are substantially identical but are mirror versions of each other. Thus, while the discussion herein focuses on the tire support 64a, it should be understood that the discussion also applies to the tire support 64b.

The tire support 64a includes two sets 68, 70 of rollers 72. The rollers 72 are arranged with their rotational axes parallel to the longitudinal axis of the vehicle 34 when placed on the support stand 42. Therefore, a vehicle with a pair of front tires placed on the rollers 72 can move laterally through the rollers 72 relative to its longitudinal axis. As best shown in Figures 4 and 5, the sets 68, 70 of rollers 72 are bent inwardly relative to each other. That is, the adjacent ends of the rollers 72 of each set 68, 70 are positioned vertically lower than the outboard ends in a V-shaped configuration. Therefore, the wheel assembly 60 of the vehicle 34 is naturally oriented to be in a fixed longitudinal position when placed on the tire support 64a, 64b along the axes 74a, 74b defined by the adjacent mounting ends of the rollers 72. It should be understood that the axes 74a, 74b are aligned with one another and perpendicular to the longitudinal axis of the vehicle when positioned on the track 48 and stand 42. As the vehicle 34 is moved onto and off the support stand 42, the tire support 64a additionally includes ramps 76, 78 for supporting the vehicle tire.

The vehicle 34 is centered or positioned on the support stand in part via a vehicle centering device 66. The vehicle centering device 66 is operable to center or position the front portion of the vehicle 34. The vehicle centering device 66 includes a pair of opposing synchronized arms or bumpers 80a, 80b configured to extend outwardly from a housing 82 to contact the inner sidewall of a tire disposed on the tire supports 64a, 64b. The arms 80a, 80b are synchronized to move outwardly evenly and simultaneously in opposite directions from the housing 82, in particular via a pair of actuators 84a, 84b (FIG. 6) coupled together and actuated by the controller 40. As can be seen from FIGS. 5 and 6, the arm 84a is fixed to or is part of a plate 86a, and the arm 84b is fixed to or is part of a plate 86b. The plates 86a, 86b are slidably mounted on rails or slides 88, 90. The extendable end 92a of the actuator 84a is attached to the plate 86a, such that the extension of the end 92a causes the arm 84a to extend outward. Similarly, the extendable end 92b of the actuator 84b is attached to the plate 86b, such that the extension of the end 92b causes the arm 84b to extend outward. The arms 80a, 80b are similarly retractable via the retraction of the ends 92a, 92b of the actuators 84a, 84b. Thus, the vehicle centering device 66 is operable to center the front portion of the vehicle 34 on the vehicle support stand 42 by the rollers 72, which are laterally movable via the even and opposite extension of the arms 80a, 80b. It should be noted that the arms 80a, 80b thus contact and press against the inner sidewall of the tire.

3, 4 and 7, the rear wheel support and centering assembly 58 includes oppositely disposed tire supports 94a, 94b positioned on opposite sides of the rear vehicle centering device 96. The tire supports 94a, 94b are configured to receive opposing tires of a pair of wheels of the wheel assembly of the vehicle 34, such as the rear wheel assembly 62 shown in FIG. 1. The tire supports 94a, 94b are substantially identical but mirror versions of each other. Thus, while the discussion herein focuses on the tire support 94a, it should be understood that the discussion also applies to the tire support 94b.

The tire support 94a includes six sets 98a-98f of rollers 100 in the illustrated embodiment. The rollers 100 are arranged with their rotational axes parallel to the longitudinal axis of the vehicle 34 when placed on the support stand 42. Therefore, a vehicle with a pair of rear tires placed on the rollers 100 can move laterally through the rollers 100 relative to its longitudinal axis. In contrast to the front wheel support and centering assembly 56, the rollers 100 of the rear wheel support and centering assembly 58 are all in the same plane. The multiple sets 98a-98f of rollers 100 allow vehicles with different wheel bases to be used on the support stand 42. That is, for example, if the wheel assemblies of the opposing front vehicles are held by the tire supports 64a, 64b, the wheel assemblies of the opposing rear vehicles can still be positioned on the tire supports 94a, 94b even with the vehicle wheel base lengths being different. Ramps may also be provided at the inlets and outlets of the tire supports 94a, 94b to assist in moving the vehicle onto and off the tire supports 94a, 94b.

The vehicle 34 is also centered or positioned on the support stand 42 in part via a rear vehicle centering device 96. The rear vehicle centering device 96 operates in a manner generally similar to the vehicle centering device 66 to center or position the rear portion of the vehicle 34. The rear vehicle centering device 96 includes multiple pairs of opposed synchronized locator arms or bumpers 102a, 102b, 104a, 104b and 106a, 106b configured to extend outwardly from a housing 108 to contact the inner sidewall of a tire disposed on the tire supports 94a, 94b. In particular, each set of opposed arms of the centering device 96 is synchronized to move outwardly evenly and simultaneously in opposite directions from the housing 108 via actuators 110, 112, 114, 116 (FIG. 7) coupled together and actuated by the controller 40. The arms 102a, 102b, 104a, 104b, 106a and 106b are slidably mounted for movement on rails or slides 118, 120, 122 and 124. This allows the movable ends 110a, 112a, 114a, 116a of the actuators 110, 112, 114, 116 to extend and retract the arms 102a, 102b, 104a, 104b, 106a and 106b relative to the housing 108, for example, via pulley linkages 126, 128. Thus, it should be noted that the vehicle centering device 96 is operable to center the rear portion of the vehicle 34 on the vehicle support stand 42 by means of rollers 100 that allow the vehicle to move laterally through equal and opposite extension of arms 102a, 102b, 104a, 104b, 106a and 106b, whereby the arms contact and press against the inner sidewall of the tire.

Although the vehicle support stand 42 is shown in the illustrated embodiment to position, center, and/or orient the vehicle 34 by arms pushing against the inner sidewall of the tire, it should be readily appreciated that alternatively constructed centering systems may be constructed in which arms or bumpers push against the outer sidewall of the tire by pushing in equal and opposite amounts from the outside of the vehicle, such as extending inwards the locator arms discussed below in conjunction with FIG. 11. Additionally, while the tire supports 64a, 64b and 94a, 94b of the system 30 are disclosed as using rollers 72, 100 for lateral adjustment of the vehicle 34 on the support stand 42, it should be understood that alternative tire supports may be used within the scope of the present invention. For example, the tire supports may be constructed as floating fixtures, such as conventional floating plates or floating plates. Such a floating plate assembly 1000 is shown in FIG. 15 along with a tire of a tire and wheel assembly 1200. As shown therein, the floating plate assembly 1000 is configured to recess into the vehicle support stand and to freely float the vehicle wheel assembly 1200 on the plate 1010 in multiple degrees of freedom, e.g., laterally relative to the longitudinal axis of the vehicle.

With the vehicle 34 centered or oriented on the stand 42 via the vehicle centering devices 66, 96, the desired target 36 is held by the tool 39 and guided by the multi-axis robotic manipulator 38 to position the target 36 for use in aligning or calibrating one or more sensors 32 of the vehicle 34. That is, the target 36 is oriented relative to the vehicle 36. In another aspect of the invention, once a particular vehicle is oriented on the stand 42, the robotic manipulator 38 is configured to select a particular target for the desired alignment or calibration of a particular sensor of that vehicle, and to position the selected target for that particular vehicle in the appropriate position for the appropriate target to perform any desired alignment or calibration of a sensor of that particular vehicle 110.

The location where the target 36 is positioned by the robot 38 is programmed into the controller 40 based on, for example, the make and model of the vehicle and the particular sensor to be aligned/calibrated. For example, with the vehicle 34 centered on the stand 42, the robot 38 can be used to place the target 36 in a particular position based on a reference point corresponding to a desired location for the target 36 based on the position of the vehicle 34. The reference point can thus be defined as the relationship between the target 36 and the centering system 66, 96 of the stand 42. Such a reference point or spatial relationship allows for accurate placement of the calibration/alignment target positioned by the robot manipulator 38. In certain embodiments, as discussed in more detail below, a master positioned on the stand 42 can be used to determine the reference point for a particular sensor of the vehicle, for example, a given make and model of vehicle.

As can be seen from FIG. 1, the vehicle support stand 42 and the target positioning system 44 are arranged at the same vertical height, so that the vehicle can be moved onto and out of the system 30. For example, the stand 42 and the system 44 can be arranged in a pit or with an entrance and exit ramp. So that the vehicle 34 can be moved onto the stand 42 for the performance of the alignment and calibration routine. The vehicle 34 is then moved in the same direction to exit the system 30. The robot 38 can be moved backwards in the longitudinal direction. The vehicle 34 is then moved to exit to the left or right. The support stand 42 and the target positioning system thus define or include a stationary support surface 129. On or across the stationary support surface 129, the vehicle 34 can be moved or moved. The wheel assembly supports 56, 58 and the robot track 48 are arranged in or on the support surface 129. As can be seen from FIGS. 1 and 2, the robot track 48 includes an upper track surface 53. The upper track surface 53 is additionally configured to allow the vehicle 34 to be moved over the upper track surface 53 based on a rail 50 disposed below the upper track surface 53.

8 and 9, an alternative robotic target alignment and ADAS sensor calibration system 130 is disclosed. The system 130 is generally similar to the system 30 discussed above. The system 130 is thus used to align a target, such as target 36, with respect to a vehicle 34, and in particular the vehicle's sensor 32 for sensor calibration/alignment. The system 130 includes a target positioning system 44 and a vehicle support stand 142 in a manner similar to the system 30. In the illustrated target positioning system 44 of FIGS. 8 and 9, the robot 38 does not hold a target. It is understood that the arm portion 38a can thereby hold a tool 39 and any of a number of targets, such as target 36. As mentioned, the base 46 can be traversed longitudinally along the track 48 via signals from a computer system or controller 140. As can be seen from FIGS. 8 and 9, the system 130 is constructed to allow an operator to work under the vehicle support stand 142. The system 130 can be used, for example, in a repair facility. This may allow the operator to conveniently perform additional operations on the vehicle 34, such as adjusting the alignment of the vehicle 34 based on the alignment information from the NCA sensor 145.

The vehicle support stand 142 uses a non-contact wheel alignment sensor system to determine the orientation of the vehicle. In the illustrated embodiment, non-contact wheel alignment sensors 145, 146 are disposed around the opposing front wheel assembly 60 and the opposing rear wheel assembly 62, respectively. The non-contact wheel alignment sensors 145, 146 are used to obtain position information of the vehicle 34 at the stand 42 that is provided to the controller 140. The controller 140, in turn, operates the robot 38 to position the target 36 relative to the sensor 32 of the vehicle 34.

The wheel alignment sensors 145, 146 may be used to determine the vertical center plane of the vehicle 34 and to determine wheel alignment characteristics such as toe, camber, caster, steering axis inclination (SAI), as well as the center, axis of symmetry, and rear thrust angle of the wheels, or portions thereof. In the illustrated embodiment of the system 130, four non-contact wheel alignment sensors 145, 146 are shown arranged around the vehicle 34. It should be understood that alternative arrangements may be used. For example, an alternative arrangement may use non-contact wheel alignment sensors on just two wheel assemblies of the vehicle 34, such as opposing wheel assemblies. The rear thrust angle may be determined using the sensor 146, for example, by rotating the rear tire and wheel assembly 62 to two or more positions, for example, by rotating the assembly 62 using the motorized roller support assembly 62. Alternatively, the vehicle may be moved between positions depending on the configuration of non-contact wheel alignment sensors being used.

The non-contact wheel alignment sensors 145, 146 shown in Figures 8 and 9 include an exterior cover or housing. As can be seen from Figure 10, each non-contact wheel alignment sensor 145, 146 in the illustrated embodiment includes a pair of individual non-contact wheel alignment sensors 145a, 145b that work in concert and are arranged to be located on the left and right sides of a wheel assembly of a given vehicle. In the illustrated embodiment of Figure 10, the non-contact wheel alignment sensor 145 is constructed in accordance with U.S. Patent Nos. 7,864,309, 8,107,062, and 8,400,624, which are incorporated herein by reference. As shown, a pair of non-contact wheel alignment ("NCA") sensors 145a, 145b are located on either side of the tire and wheel assembly 60 of the vehicle 34. The NCA sensors 145a, 145b project illumination lines 164 on both sides of the tire, with the left side 166a shown. The NCA sensors 145a, 145b receive reflections of the illumination lines 164, allowing the non-contact wheel alignment system to determine the orientation of the tire and wheel assembly 60. The multiple illumination lines 164 projected onto the tire and wheel assembly 60 and the positions of these lines 164 in the resulting image allow the three-dimensional spatial orientation or shape of the tire and wheel assembly 60 to be calculated based on the field of view and depth of field of the sensors through the operating range of the sensors 145a, 145b. Corresponding NCA sensors 145a, 145b are positioned around all four tire and wheel assemblies 60, 62 of the vehicle 34. Vehicle position information may be determined by the non-contact wheel alignment system. This determination may be based on the known orientations of the NCA sensors 145a, 145b positioned around the vehicle 34 on the stand 142. The rear non-contact wheel alignment sensor 146 may be longitudinally adjustable to accommodate vehicles with different wheel base lengths. As mentioned, the wheel alignment and vehicle position information is provided to a controller, such as the controller 140 or a remote computer, for example, via the Internet. In response to the wheel assembly alignment and vehicle position information, the controller 140 or the remote computer may then operatively send a signal to operate the robot 38 to position the target 36 relative to the sensor 32 of the vehicle 34. In an alternative arrangement, a single non-contact wheel alignment sensor may be configured to project a line onto both the left and right sides of the tire and wheel assembly and capture an image of the corresponding reflection for purposes of determining the shape of the wheel and the associated vehicle position.

In the illustrated embodiment, the vehicle support stand 142 includes a tire support including a pair of rollers 168 disposed on each of the wheel assemblies 60, 62 of the vehicle 34. Thereby, the vehicle 34 can remain stationary on the stand 142 while the wheel assemblies 60, 62 can be rotated during alignment and position analysis. The rear pair of rollers 168 can be longitudinally movable to accommodate vehicles with different wheel bases. Additionally, as can be seen from FIG. 11, an extendable and retractable locator arm 170 can be positioned on each non-contact wheel alignment sensor 145. The locator arm 170 can be extended to contact the outer sidewall of the tire of the tire and wheel assembly disposed on the roller 168 to help hold the vehicle 34 in a fixed location while on the roller 168. The roller 168 can be moved to rotate the tire and wheel assembly thereon. It should be further appreciated that the vehicle can be moved laterally, for example, via force from the locator arm 170.

It should be understood that alternative NCA sensors for sensors 145a, 145b may be used, including stand-based systems and drive-through non-contact alignment systems in which vehicle position is determined. In stand-based systems, the vehicle remains stationary and wheel alignment and vehicle position information is measured at two separate locations. For example, robotic alignment of a target in front of a vehicle for calibration of vehicle sensors may be performed using a system for determining wheel alignment and vehicle position based on the movement of the vehicle past vehicle wheel alignment sensors. This system is known in the art. Based on the vehicle orientation and alignment information from such sensors, the controller may determine a location for installation or positioning of a target adjustment frame as disclosed above. For example, the vehicle may be moved along or by such sensors located on both sides of the vehicle and stopped within the sensor field. This allows the controller 140 to position the target 36 in an appropriate location relative to the vehicle 34, and in particular relative to the sensors of the vehicle that are to be aligned and calibrated. Such drive-through systems are known in the art.

According to another aspect of the invention, the chassis height of the vehicle 34 may be determined to further assist in orienting targets via the robotic manipulator relative to the vehicle's position. For example, the chassis height may be determined at multiple locations around the vehicle such that the absolute height, pitch and yaw of sensors (e.g., LDW or ACC sensors) mounted on the vehicle may be determined. The chassis height measurements may include measuring the fender height. Any conventional method for determining the chassis height of a vehicle may be used. For example, one or more leveled lasers may be aimed at additional height targets mounted on the vehicle, such as a fender of the vehicle or mounted elsewhere, such as a height target magnetically attached to the vehicle. In another example, the non-contact wheel alignment sensor 145 described herein may be used to obtain the fender height. For example, the projected light may be projected onto a portion of the vehicle, such as a fender at or adjacent to the wheel well.

Determination of the reference point for placing the target relative to the support stand 42 or the vehicle on the support stand 142 may also be done through a calibration process. In one example of a calibration process, referring to FIG. 12, the calibration master 34a may be positioned on a support stand, such as the support stand 142 with the non-contact wheel alignment sensor 145. The master 34a may be a specially constructed object with known dimensions or a vehicle that has been precisely measured and placed in a known position on the stand 142 via the non-contact wheel alignment sensor 145. The master 34a may also include a light projector precisely oriented relative to the centerline of the calibration master 34a. The calibration master 34a is configured such that the light projector directs light such that the centerline of 34a is aligned with the robot 38. For example, a target held by the robot 38 may be oriented in place by rocking the robot 38 until the light projected from the master 34a hits the desired location of the target. The controller 140 is thereby "taught" a specific location and is operable to position the target accordingly. Alternatively, during calibration, the robot 38 can optionally be moved between two distances, shown as "Position 1" and "Position 2" in FIG. 12, to align the target 36 with the calibration master 34a.

For example, at position 1, the robot 38 may be adjusted to align the target 36 with the desired orientation relative to the projector by rocking the position of the robot to position the target 36 so that the projected light will again hit the desired location relative to the projector. The robot 38 is then moved to position 2. The robot 38 is again adjusted to align the target 36 with the desired orientation relative to the projector by rocking the position of the robot 38 to position the target 36 so that the projected light will again hit the desired location. In this manner, the axis of the calibration master 34a relative to the target 36 is established and known. As discussed herein, there may be a calibration master 34a for each type of vehicle (e.g., automobile, pickup truck, van) or, in the alternative, there may be a calibration master 34a for each make and model of vehicle to undergo alignment/calibration. A similar calibration process may be used with the stand 42 in which the calibration master 34a is positioned via the centering devices 66, 96. It should be appreciated that for system 130, a determination of the actual vehicle orientation obtained via non-contact wheel alignment sensor 145 for a given vehicle 34 can be used as an offset to adjust the position of target 36 relative to a predetermined position based on master 34a.

The robot alignment and calibration system 30, 130 discussed above may be configured to operate independently of external data, information or signals. In this case, the computer system of the embodiment including the controller 40, 140 listed may be programmed for operation with various makes, models and installed sensors and may include the use of an operator computer device. In such a standalone configuration, as shown for the system 30 in FIG. 13, the operator computer device 176 may interface with the vehicle 34 via one or more ECUs 178 of the vehicle 34, which may interface with the vehicle 34 via an on-board diagnostics (OBD) port of the vehicle 34, and with the controller 40 to provide instructions to the operator to operate the system for alignment/calibration of the sensor 32. Alternatively, the operator computer device 176 may receive information entered by an operator regarding the vehicle 34, for example, by manual entry or scanning, such as information regarding the make, model, vehicle identification number (VIN) and/or installed sensors. The device 176 communicates such information to the controller 40.

As an alternative to such a stand-alone configuration, FIG. 13 also discloses an exemplary embodiment of a remote interface configuration for the system 30. The system 30 is configured to interface with a remote computer or system 180, such as a server, and one or more remote databases 182, which may be accessed, for example, via the Internet 184. The computer system thereby further includes the remote computer 180. For example, the remote computer 180, including the database 182 accessed via the Internet, may be used to execute a calibration sequence through one or more engine control units ("ECUs") of the vehicle 34 to calibrate one or more ADAS sensors according to pre-established programs and methodologies, for example based on the original factory calibration sequence or based on an alternative calibration sequence. In such a configuration, the controller 40 need not include a program related to target positioning parameters for a particular make, model, and installed sensor. Rather, an operator may connect an operator computer device 176 to the ECU 178 of the vehicle 34. The computer device 176 then sends the resulting vehicle-specific information to the computing system 180. Or alternatively, the operator can directly input information into the operator computing device 176 without connecting to the vehicle 34 for transmission to the computing system 180. Such information can be, for example, make, model, vehicle identification number (VIN) and/or information regarding the installed sensors. The computing system 180 can then provide the necessary instructions to the operator based on the specific procedure required to calibrate the sensors defined in the database 182 and the specific processing performed by the computing system 180. Control signals are then sent to the controller 40. For example, the computing system 180 can provide instructions to the controller 40 for positioning the target 36 via the robot 38 and for performing an OEM calibration sequence of the sensor 32 via, for example, the ECU 178.

The database 182 may thus include information for performing the calibration process, such as the particular target to be used for a given vehicle and sensor, information regarding where the target will be positioned by the robot 38 relative to such sensor and vehicle, and information for performing or initiating a sensor calibration routine. Such information may be in accordance with OEM processes and procedures or alternative processes and procedures. In any embodiment, various levels of autonomous driving by the system 30 may be used.

An exemplary calibration cycle according to an embodiment of the present invention is shown in FIG. 14. In step 200, the calibration master 34a is positioned and oriented on the vehicle support stand 42, 142 of the test system 30, 130. In the case of the system 30, the centering device 66, 96 is used to position the calibration master 34a. In the case of the system 130, the locator arm 170 of each non-contact wheel alignment sensor 145 is used to position the calibration master 34a by contacting a side of the calibration master 34a to oriented the calibration master 34a. With the calibration master 34a oriented, in step 202 of FIG. 14, one or more reference positions or points can be determined between the target 36 or robot 38 and the calibration master 34a. This determination includes determining longitudinally, laterally, and vertically and for a given axis of rotation. The calibration master 34a can then be removed from the vehicle support stand 42, 142.

In step 204 of FIG. 14, the vehicle 34 is set up for testing. For example, the vehicle 34 is placed on the stand 42, 142 so that the vehicle's wheels are positioned on the rollers of the test stand. As a result, the vehicle 34 is roughly aligned with the target 36. The model and version of the car is also entered into the calibration system 30, 130, for example, via the operator calculator 176. At the same time, the OBD2 connector is connected to the OBD2 port of the vehicle 34, and a communication connection is established between the vehicle 34 and the controller 40, 140.

In step 206 of FIG. 14, the vehicle 34 is set up so that it is oriented in the same way as the calibration master 34a. For system 30, the centering devices 66, 96 are used to orient the vehicle. For system 130, the locator arm 170 engages the tire sidewall and the non-contact wheel alignment sensor 145 is used to obtain the orientation of the vehicle 34. An operator may initiate the automated positioning/orientation operation via the controller 40, 140 or via the operator computer 176.

14, the thrust angle of the vehicle 34 may be desired or required for calibration of a particular sensor such that the thrust angle may be determined in step 208. In the case of the system 130, for example, the thrust angle may be determined based on calculations and measurements made by the non-contact wheel alignment sensor 145. The determined thrust angle may then be used in positioning the target 36 by the robot 38 via the controller 140.

In step 210 of FIG. 14, a given target 36 is selected and positioned for individual ADAS system calibration. As discussed herein, an operator may initiate an automated target selection and positioning operation for a given ADAS sensor 32 via the controller 40, 140 or operator calculator 176. The target selection and positioning operation may take into account the make and model of the vehicle and the calibration/alignment procedure for the particular ADAS sensor 32 that may be selected by the operator. When positioning the target 36, the target 36 is positioned relative to a predetermined reference point or location such that the selected target 36 is properly centered and positioned relative to the vehicle 34, and particularly relative to the particular sensor 32 that is to be calibrated.

In step 212 of FIG. 14, calibration of the ADAS systems (e.g., ACC, LDW, and NIVI) in the vehicle 110 may be performed, for example, according to OEM calibration routines. Based on a fixed and known orientation of the vehicle 34, individual sensor calibration operations, for example, for LDW, ACC, etc., may be performed with minimal operator interaction required.

It should be understood that the steps recited above with respect to the operation of FIG. 14 may be implemented in other ways, particularly in orders, processes, or operations, and still be in accordance with the present invention.

Yet another alternative vehicle support stand 242 is shown in FIG. 16. Here, the vehicle support stand 242 is configured as a lift 221 that can be used with the target location system 44 of FIGS. 1 and 8. The support stand 242 can be used, for example, in a repair facility. Thereby, an operator 247 can conveniently perform additional operations on the vehicle 34, such as adjusting the alignment of the vehicle 34, in addition to calibrating the ADAS sensors of the vehicle 34. In particular, for example, the alignment of the vehicle 34 can be performed based on alignment information from an NCA sensor 245 mounted on the lift 221. The sensor 245 can be constructed in a manner similar to the NCA sensors 145, 146 discussed above. FIG. 16 additionally shows the inclusion of a combined controller and operator calculator 240 for use by the operator 247. Alternatively, the lift 221 may be used in conjunction with a centering device in a manner similar to the centering devices 66, 96 disclosed above to center the vehicle 34 on the stand 242 for calibration of the ADAS sensor 32 on the vehicle 34 without the use of the NCA sensor 245.

In use, when the lift 221 is in the lowered orientation, the vehicle 34 is moved onto the runway 249 of the lift 221. The vehicle 34 is then positioned in an initial position, and the NCA sensor 245 is used to determine the wheel alignment of the vehicle 34 and the position of the vehicle 34 on the stand 242. The vehicle 34 can then be positioned to be in a second position or calibration orientation, for example by rotating the wheels 180 degrees by rolling the vehicle 34. The NCA sensor 245 is then again used to determine the wheel alignment of the vehicle 34 and the position of the vehicle 34 on the stand 242. The two sets of determinations allow the determination of the runout correction thrust angle of the vehicle 34. The target 36 held by the robotic manipulator 38 of the target position system 44 can then be positioned to be in a desired orientation for calibration of the sensors of the ADAS vehicle 34. The lift 221 is shown in an elevated orientation in FIG. However, it should be understood that the lift 221 can be lowered to approximately flush with the target position system 44 for calibration of the vehicle 34 sensors. Alternatively, calibration of the sensors via the target 36 held by the robotic arm 38 can be performed while the lift 321 is in the elevated position.

Other variations and modifications of the specifically described embodiments may be made without departing from the spirit of the invention, which is intended to be limited only by the scope of the appended claims, as interpreted in accordance with the principles of patent law, including the doctrine of equivalents.

Claims (28)

1. A robotic system for aligning a target with respect to an equipped vehicle for calibration of a sensor of the equipped vehicle, comprising:
a vehicle support stand in which an equipped vehicle is stationarily positioned at an established known position for calibration of the equipped vehicle's sensors;
a robotic manipulator that is longitudinally movable toward and away from the vehicle support stand, the robotic manipulator including a multi-axis robotic arm;
a target, the robotic arm configured to movably hold the target for multi-axis movement of the target;
the robot manipulator is configured to position the target in a calibration position relative to the sensor of the installed vehicle by longitudinal movement of the robot manipulator relative to the vehicle support stand and by movement of the robot arm based on the established known position of the installed vehicle on the vehicle support stand, so that the sensor can be calibrated using the target ;
the vehicle support stand including a plurality of locator arms;
the locator arm is extendable and retractable and configured to press against a tire and wheel assembly of the mounted vehicle to orient and center the mounted vehicle in a known position on the vehicle support stand;
the robotic manipulator is attached to a base;
the base is longitudinally movable along a track in a floor support surface;
The truck is positioned in front of the stationarily positioned equipped vehicle when the stationarily positioned equipped vehicle is on the vehicle support stand . Contains multiple targets,
the robotic manipulator includes an end effector disposed on the robotic arm;
2. The robotic system of claim 1, wherein the end effector is configured to selectively grasp a selected one of the targets from the plurality of targets for use with an equipped vehicle stationarily positioned on the vehicle support stand . the track includes a rail;
The robot system of claim 1 , wherein the base is movable along the rails, the rails being positioned vertically lower than the floor support surface. the locator arms include a set of forward facing arms and aft facing arms;
2. The robotic system of claim 1 , wherein the front opposing arms are configured to extend evenly in opposite directions from each other and the rear opposing arms are configured to extend evenly in opposite directions from each other. the vehicle support stand includes a movable front tire support and a movable rear tire support;
The robotic system of claim 1 , wherein the movable front tire support and the movable rear tire support carry opposed sets of tires of the equipped vehicle. The robotic system of claim 5 , wherein the front tire support includes a front roller and/or the rear tire support includes a rear roller. The robot system of claim 6 , wherein the rotation axis of the front rollers and/or the rotation axis of the rear rollers are aligned with a longitudinal axis of the equipped vehicle. the vehicle support stand including a pair of movable front tire supports;
a pair of movable front tire supports each of which is disposed on a front opposing set of tires of the equipped vehicle;
2. The robotic system of claim 1, wherein each of the front tire supports includes two sets of rollers, the two sets of rollers of each of the front tire supports being angled together in a V-shaped configuration to position the equipped vehicle. the vehicle support stand including a pair of movable rear tire supports;
9. The robotic system of claim 8 , wherein the pair of movable rear tire supports are disposed on each of a rear opposing set of tires of an installed vehicle, and each of the rear tire supports includes at least one set of rollers. the vehicle support stand includes a front centering device;
2. The robotic system of claim 1, wherein the forward centering device is positioned under the equipped vehicle when the equipped vehicle is placed on the vehicle support stand, the forward centering device including a pair of locator arms configured to synchronously extend outwardly to engage the inside of a front tire and wheel assembly of the equipped vehicle. 11. The robotic system of claim 10, wherein the vehicle support stand includes a rear centering device disposed under the equipped vehicle when the equipped vehicle is placed on the vehicle support stand, the rear centering device including a pair of locator arms configured to synchronously extend outwardly to engage the inside of a rear tire and wheel assembly of the equipped vehicle . the vehicle support stand further including a pair of front non-contact wheel alignment sensors positioned adjacent a front facing tire and wheel assembly of the installed vehicle when placed on the vehicle support stand;
2. The robotic system of claim 1, wherein the forward non-contact wheel alignment sensor is operable to determine vehicle orientation information to determine the established known position of the equipped vehicle for use in positioning the target at the calibration position. the vehicle support stand further including a pair of rear non-contact wheel alignment sensors positioned adjacent a rear opposed tire and wheel assembly of the installed vehicle when placed on the vehicle support stand;
13. The robotic system of claim 12, wherein the rear non-contact wheel alignment sensor is operable to determine vehicle orientation information to determine the established known position of the equipped vehicle for use in positioning the target at the calibration position . The robotic system of claim 1, wherein the vehicle support stand is positioned above a pit configured to allow an operator to work on the equipped vehicle from beneath the equipped vehicle. the vehicle support stand including a lift configured to raise and lower the equipped vehicle when positioned on the vehicle support stand;
The robotic system of claim 1 , wherein the equipped vehicle is movable onto and off of the lift when the lift is lowered. a plurality of non-contact wheel alignment sensors mounted on said lift;
the non-contact wheel alignment sensor is positioned adjacent opposed tire and wheel assemblies of the installed vehicle when the installed vehicle is placed on the vehicle support stand;
16. The robotic system of claim 15, wherein the non-contact wheel alignment sensor is operable to determine vehicle orientation information to determine the established known position of the equipped vehicle for use in positioning the target at the calibration position . 20. The robotic system of claim 16 , wherein the lift includes a runway, the runway including a movable tire support. 1. A method for robotically aligning a target with respect to an equipped vehicle for calibration of sensors on the equipped vehicle, comprising:
guiding an equipped vehicle onto a stationary vehicle support stand, the equipped vehicle including a sensor and stationarily positioned on the vehicle support stand;
moving a target held by a robotic manipulator to a calibration position for calibrating the sensor based on an established known position of the installed vehicle on the vehicle support stand;
performing a calibration routine whereby the sensor is calibrated using the target;
the robotic manipulator is movable longitudinally relative to a longitudinal axis of the mounted vehicle on the vehicle support stand, the robotic manipulator including a multi-axis robotic arm, the robotic arm configured to hold the target ;
the robotic manipulator is attached to a base;
the base is longitudinally movable along a track in a floor support surface;
the vehicle support stand including a plurality of locator arms;
wherein the locator arm is extendable and retractable and configured to press against a tire and wheel assembly of the mounted vehicle to orient and center the mounted vehicle in a known position on the vehicle support stand . the robotic manipulator includes an end effector disposed on the robotic arm;
20. The method of claim 18 , wherein the end effector is configured to selectively grasp the target from a plurality of targets for use with an equipped vehicle stationarily positioned on the vehicle support stand . the vehicle support stand includes a movable front tire support and a movable rear tire support;
20. The method of claim 18 , wherein opposed sets of tires of the equipped vehicle are disposed on the movable front tire support and the movable rear tire support. the vehicle support stand further including a pair of front non-contact wheel alignment sensors positioned adjacent a front facing tire and wheel assembly of the installed vehicle when placed on the vehicle support stand;
20. The method of claim 18, wherein the front non-contact wheel alignment sensor is operable to determine vehicle orientation information to determine the established known position of the equipped vehicle for use in positioning the target at the calibration position . the vehicle support stand further including a pair of rear non-contact wheel alignment sensors positioned adjacent a rear opposed tire and wheel assembly of the installed vehicle when placed on the vehicle support stand;
22. The method of claim 21, wherein the rear non-contact wheel alignment sensor is operable to determine vehicle orientation information to determine the established known position of the equipped vehicle for use in positioning the target at the calibration position . The method of any one of claims 18 to 22 , wherein said directing the equipped vehicle onto the vehicle support stand comprises moving the equipped vehicle onto the support stand. 24. The method of claim 23 , further comprising moving the equipped vehicle off of the vehicle support stand after performing a calibration routine. 25. The method of claim 24, wherein said moving the equipped vehicle out of the vehicle support stand includes moving the equipped vehicle in the same direction as the equipped vehicle was moved onto the vehicle support stand . 26. The method of claim 25 , wherein the moving the rigged vehicle out of the vehicle support stand comprises moving the rigged vehicle towards the robotic manipulator. 27. The method of claim 26 , further comprising: moving the robotic manipulator longitudinally away from the vehicle support stand prior to said moving the equipped vehicle out of the vehicle support stand. said moving the equipped vehicle out of the vehicle support stand includes moving the equipped vehicle across a vehicle support surface;
25. The method of claim 24 , wherein the robotic manipulator is mounted for longitudinal movement on the vehicle support surface and/or across a track for the robotic manipulator.

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