Patent Publication Number: US-2023145082-A1

Title: System and method for automated extrinsic calibration of lidars, cameras, radars and ultrasonic sensors on vehicles and robots

Description:
CROSS- REFERENCE TO RELATED APPLICATIONS 
     This application claims the benefit of, and priority to, U.S. Provisional Application Serial No. 63/276,823, filed on Nov. 8, 2021, the disclosure of which is hereby incorporated herein by reference in its entirety and for all purposes. 
    
    
     FIELD 
     The disclosed embodiments relate generally to data processing systems and more particularly, but not exclusively, to data processing systems and methods suitable for performing automated extrinsic calibration of lidars, cameras, radars and ultrasonic sensors on vehicles and robots. 
     BACKGROUND 
     Sensors, such as cameras, lidars, radars and ultrasonics, are starting to become ubiquitous in modern consumer vehicles. Such sensors enable a number of key Advanced Driver Assistance (ADAS) applications such as Backup Monitoring, Lane Keep Assist, Lane Departure Warning, Lane Centering, Automatic Emergency Braking, Forward Collision Warning, Pedestrian and Cyclist Emergency Braking, Adaptive Cruise Control, Blind Spot Monitoring, etc. Further, such sensors are also used for a number of robotics applications such as warehouse automation tasks, autonomous driving, unmanned aerial vehicles, etc. 
     One requirement for a functional sensor system is precise extrinsic and intrinsic calibration. Intrinsic calibration is needed to understand a relationship between internal transmitters, detectors and pixels and the direction of the incoming signal that ultimately forms a two-dimensional or three-dimensional image of the world. Extrinsic calibration deals with determining the precise spatial transformation between the sensor and the body frame of the vehicle or robot on which the sensor is rigidly installed. These extrinsic parameters change every time the sensor is moved, reinstalled or repositioned relative to the vehicle’s body frame. For instance, cameras attached on the windshield of a vehicle will experience a change in extrinsic parameters when the windshield is replaced or reinstalled. Sometimes, changing the ride height of the vehicle by swapping with larger wheels can also lead to a changed extrinsic calibration as the sensor now views the road from a larger height above ground level. These are just a few examples of scenarios that require extrinsic calibration of the sensors. 
     Inaccurate calibration can lead to disastrous outcomes in driver assistance. For example, a poorly calibrated forward-facing camera or lidar that is misaligned by just two degrees can incorrectly position a vehicle that is two hundred feet ahead into its adjacent lane and thereby lead to a potential accident. 
     The state-of-the-art solutions in the market for extrinsic static sensor calibration are very manual in their process. The typical solution involves using: 
     a plumbline and laser pointer or line marker for measuring the vehicle centerline;   a multitude of measuring tapes to measure accurate distance and manually place an adjustable jig in front of vehicle at a specific distance;   wheel clamps with laser dot based manual system for adjusting the jig to be perpendicular to vehicle centerline at the right distance;   manual adjustment of height of jig to be at right height needed for specific vehicle’s calibration procedure;   manual placement of printed stationary targets on the jig with the correct orientation;   ensuring sufficient lighting and reduced clutter behind calibration area; and   ensuring sufficient working area in well-lit area with perfectly flat ground.   

     Each of these requirements make the calibration task extremely complicated. The requirements require hours of human intervention and rely heavily on the technician’s measurement skills and attention to detail. One small mistake or omission can lead to incorrect calibration that has severe implications for the intended driver assistance use case of the camera. 
     In view of the foregoing, a need exists for an improved system and method for performing automated extrinsic calibration of lidars, cameras, radars and ultrasonic sensors on vehicles and robots that overcomes the aforementioned obstacles and deficiencies of currently-available systems. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG.  1    is a high level block diagram illustrating an exemplary embodiment of an automated extrinsic calibration system for a device under test that is associated with a sensor system disposed at a turntable system. 
         FIG.  2 A  is a high level block diagram illustrating an exemplary alternative embodiment of the automated extrinsic calibration system of  FIG.  1   , wherein the automated extrinsic calibration system includes a robotic arm for positioning a first selected calibration target device at a first predetermined distance from the device under test. 
         FIG.  2 B  is a high level block diagram illustrating an exemplary alternative embodiment of the automated extrinsic calibration system of  FIG.  2 A , wherein the robotic arm positions a second selected calibration target device at a second predetermined distance from the device under test. 
         FIG.  3    is a detail drawing illustrating another exemplary alternative embodiment of the automated extrinsic calibration system of  FIG.  1   , wherein the automated extrinsic calibration system includes a pair of Light Detection and Ranging (or LiDAR) systems disposed about a periphery of the turntable system. 
         FIG.  4 A  is a high level flow chart illustrating an exemplary embodiment of an automated extrinsic calibration method for the device under test of  FIG.  1   . 
         FIG.  4 B  is a high level flow chart illustrating an exemplary alternative embodiment of the automated extrinsic calibration method of  FIG.  4 A , wherein the automated extrinsic calibration method includes scanning the device under test. 
         FIG.  5 A  is a high level flow chart illustrating an exemplary alternative embodiment of the automated extrinsic calibration method of  FIG.  4 B , wherein the automated extrinsic calibration method includes identifying the device under test. 
         FIG.  5 B  is a high level flow chart illustrating another exemplary alternative embodiment of the automated extrinsic calibration method of  FIGS.  4 A-B , wherein the automated extrinsic calibration method includes positioning a selected target calibration device relative to the device under test. 
         FIG.  6 A  is a detail drawing illustrating a top view of still another exemplary alternative embodiment of the automated extrinsic calibration system of  FIG.  1   , wherein the automated extrinsic calibration system is configured to calibrate a sensor system associated with a passenger vehicle. 
         FIG.  6 B  is a detail drawing illustrating a side view of the automated extrinsic calibration system of  FIG.  6 A . 
         FIG.  7    is a detail drawing illustrating yet another exemplary alternative embodiment of the automated extrinsic calibration system of  FIG.  1   , wherein the automated extrinsic calibration system is configured to perform a static sensor system calibration. 
         FIG.  8 A  is a detail drawing illustrating an exemplary alternative embodiment of the automated extrinsic calibration system of  FIGS.  2 A-B , wherein the calibration target device comprises a calibration target device with first calibration indicia for calibrating a camera imaging system associated with the device under test. 
         FIG.  8 B  is a detail drawing illustrating an exemplary alternative embodiment of the calibration target device for calibrating the camera imaging system of  FIG.  8 A , wherein the calibration target device includes second calibration indicia for calibrating the camera imaging system. 
         FIG.  9 A  is a detail drawing illustrating another exemplary alternative embodiment of the automated extrinsic calibration system of  FIGS.  2 A-B , wherein the calibration target device comprises a calibration target device with first calibration indicia for calibrating a LiDAR imaging system associated with the device under test. 
         FIG.  9 B  is a detail drawing illustrating an exemplary alternative embodiment of the calibration target device for calibrating the camera imaging system of  FIG.  9 A , wherein the calibration target device includes second calibration indicia for calibrating the LiDAR imaging system. 
         FIG.  10 A  is a detail drawing illustrating still another exemplary alternative embodiment of the automated extrinsic calibration system of  FIGS.  2 A-B , wherein the calibration target device comprises a calibration target device with first calibration indicia for calibrating a RADAR imaging system associated with the device under test. 
         FIG.  10 B  is a detail drawing illustrating an exemplary alternative embodiment of the calibration target device for calibrating the camera imaging system of  FIG.  10 A , wherein the calibration target device includes second calibration indicia for calibrating the RADAR imaging system. 
         FIG.  11 A  is a detail drawing illustrating a top view of still another exemplary alternative embodiment of the automated extrinsic calibration system of  FIG.  1   , wherein the automated extrinsic calibration system is configured to calibrate the sensor system that is associated with a front region of the device under test. 
         FIG.  11 B  is a detail drawing illustrating a top view of still another exemplary alternative embodiment of the automated extrinsic calibration system of  FIG.  1   , wherein the automated extrinsic calibration system is configured to calibrate the sensor system that is associated with a side region of the device under test. 
         FIG.  11 C  is a detail drawing illustrating a top view of still another exemplary alternative embodiment of the automated extrinsic calibration system of  FIG.  1   , wherein the automated extrinsic calibration system is configured to calibrate the sensor system that is associated with a rear region of the device under test. 
         FIG.  12    is a detail drawing illustrating an embodiment of a control system of the automated extrinsic calibration system of  FIG.  3   . 
         FIG.  13    is a detail drawing illustrating an embodiment of a three-dimension reconstruction system of the control system of  FIG.  12   , wherein the three-dimension reconstruction system can reconstruct a registered point cloud image of the device under test. 
         FIG.  14    is a detail drawing illustrating an embodiment of a machine learning system of the control system of  FIG.  12   , wherein the machine learning system can decipher one or more aspects and/or segments of the device under test based upon the registered point cloud image. 
         FIG.  15    is a detail drawing illustrating an embodiment of a target placement simulator system of the control system of  FIG.  12   , wherein the target placement simulator system can be used for designing calibration procedures for specific types of devices under test and sensor systems. 
     
    
    
     It should be noted that the figures are not drawn to scale and that elements of similar structures or functions may be generally represented by like reference numerals for illustrative purposes throughout the figures. It also should be noted that the figures are only intended to facilitate the description of the preferred embodiments. The figures do not illustrate every aspect of the described embodiments and do not limit the scope of the present disclosure. 
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In view of complicated, manual requirements of conventional extrinsic static sensor calibration processes, a system and method for performing automated extrinsic calibration of lidars, cameras, radars and ultrasonic sensors can prove desirable and provide a basis for a wide range of applications, such as calibration of sensors associated with vehicles and/or robots. This result can be achieved, according to one embodiment disclosed herein, by a sensor calibration system  100  as illustrated in  FIG.  1   . 
     Turning to  FIG.  1   , the sensor calibration system  100  is shown as including a turntable system  110  for supporting and/or rotating a device under test  200  that can be associated with a sensor system (or circuit)  210 . Exemplary devices under test  200  can include, but are not limited to, a passenger vehicle, a self-driving vehicle, an unmanned aerial vehicle and/or a robotic system. The sensor system  210  can be disposed at any suitable location of the device under test  200 . In selected embodiments, the sensor system  210  can be disposed on a preselected surface of the device under test  200  and/or can be at least partially disposed within a preselected region of the device under test  200 . The sensor system  210 , for example, can be disposed at a roof, a bumper, a grille, a sideview mirror, a rearview mirror and/or a hood of a passenger vehicle. 
     Exemplary sensor systems  210  can include one or more camera systems, one or more Light Detection and Ranging (or LiDAR) systems, one or more Radio Detection and Ranging (or RADAR) systems and/or one or more ultrasonic systems, without limitation. When associated with a passenger vehicle and/or commercial vehicle, for example, the sensor system  210  can support one or more Advanced Driver Assistance (ADAS) applications, such as Backup Monitoring, Lane Keep Assist, Lane Departure Warning, Lane Centering, Automatic Emergency Braking, Forward Collision Warning, Pedestrian and Cyclist Emergency Braking, Adaptive Cruise Control, Blind Spot Monitoring, etc. The sensor system  210 , additionally and/or alternatively, can comprise Autonomous Vehicle (AV) sensor system that can be associated with a passenger vehicle, a commercial vehicle, or any other suitable type of device under test  200 . 
     The sensor calibration system  100  advantageously can perform extrinsic calibration on the sensor system  210 . The extrinsic calibration can be performed on the device under test  200  and/or sensor system  210  at any suitable time. For example, the sensor calibration system  100  can perform an initial extrinsic calibration when the sensor system  210  is initially installed on the device under test  200  as original equipment and/or as an aftermarket addition to the device under test  200 . The sensor calibration system  100  optionally can support periodic or otherwise time-based extrinsic calibrations on the sensor system  210 , such as a part of regular maintenance on the device under test  200 . Additionally and/or alternatively, the sensor calibration system  100  can support event-based extrinsic calibrations on the sensor system  210  such as after the device under test  200  and/or the sensor system  210  has been involved in a collision or has otherwise been damaged. 
     The turntable system  110  can include a turntable motor system  116  (shown in  FIG.  6 A ) for rotating a testing region  112  at which the device under test  200  can be disposed during the extrinsic calibration. If the testing region  112  comprises a recessed testing surface or, as shown in  FIG.  1   , an elevated testing surface, the turntable system  110  can be associated with a ramp or other inclined region  114  for facilitating disposal of the device under test  200  on the testing region  112 . The inclined region  114  can be separate from, or at least partially integrated with, the turntable system  110 . The testing region  112  preferably has a suitable size, diameter, shape and/or other dimension for accommodating a variety of devices under test  200  with different shapes, sizes and/or weights. 
     The sensor calibration system  100  likewise can include at least one calibration target system  120  that can be disposed adjacent to the turntable system  110 . The calibration target system  120  can be associated with one or more calibration target devices  122  each having at least one predetermined grid pattern or other calibration indicia  124 . At least one calibration target device  122  can be selected for coupling with a calibration target positioning system  126 . In selected embodiments, the calibration target devices  122  can include calibration indicia  124  that are associated with respective devices under test  200  and/or sensor systems  210  such that the calibration indicia  124  of the selected calibration target device  122  can be suitable for calibrating the device under test  200  and/or sensor system  210  disposed at the turntable system  110 . The calibration target device  122  optionally can include calibration indicia  124  that is associated with more than one device under test  200  and/or sensor system  210  for enabling the calibration target device  122  to be suitable for use during calibration of more than one device under test  200  and/or sensor system  210 . 
     As illustrated in  FIG.  1   , the calibration target positioning system  126  can arrange the selected calibration target device  122  at a predetermined distance D, elevation, orientation, angle and/or other position attribute relative to the device under test  200  and/or sensor system  210 . The calibration target positioning system  126 , in other words, can raise and/or lower the selected calibration target device  122  relative to the turntable system  110  and/or the device under test  200  and/or sensor system  210  disposed at the turntable system  110 , horizontally, diagonally and/or vertically rotate the selected calibration target device  122  relative to the turntable system  110  and/or the device under test  200  and/or sensor system  210  disposed at the turntable system  110  and/or translate the selected calibration target device  122  relative to the turntable system  110  and/or the device under test  200  and/or sensor system  210  disposed at the turntable system  110 . In selected embodiments, the calibration target positioning system  126  itself can translate or otherwise move relative to the device under test  200  and/or sensor system  210  for arranging the predetermined distance D or other position attribute of the selected calibration target device  122 . The calibration target positioning system  126 , for example, can translate radially toward and/or away from the turntable system  110 . 
     The translation of the selected calibration target device  122  can include, for example, moving the selected calibration target device  122  toward and/or away from the turntable system  110  and/or the device under test  200  and/or sensor system  210  disposed at the turntable system  110 . In selected embodiments, the calibration target positioning system  126  can arrange at least one position attribute of the selected calibration target device  122  relative to a predetermined point or location of the device under test  200  and/or sensor system  210 . The calibration target positioning system  126  optionally can adjust at least one position attribute, such as the distance D, through a preselected range of position attribute values. 
       FIG.  1    shows that the calibration target positioning system  126  can include a positioning system base  128  for supporting the calibration target positioning system  126  and a positioning system member  127  for coupling the selected calibration target device  122  with the positioning system base  128 . The positioning system base  128  can comprise an elongated base with a proximal end region that is adjacent to the turntable system  110  and a distal end region that is distant from the turntable system  110 . Stated somewhat differently, the proximal end region of the positioning system base  128  can be disposed between the distal end region of the positioning system base  128  and the turntable system  110 . The positioning system member  127  thereby can traverse between the proximal and distal end regions of the positioning system base  128  for adjusting the distance D between the selected calibration target device  122  and the turntable system  110  and/or the device under test  200  and/or sensor system  210 . 
     In selected embodiments, the calibration target positioning system  126  can arrange at least one position attribute of the selected calibration target device  122  relative to the device under test  200  and/or sensor system  210  in an automated manner. The calibration target positioning system  126 , for example, can comprise a robot, wherein the positioning system member  127  comprises a robotic arm  125  as illustrated in  FIGS.  2 A-B . Turning to  FIG.  2 A , the robotic arm  125  is shown as comprising an articulated robotic arm with a plurality of arm segment members  125 A and an arm joint member  125 B disposed between each pair of adjacent segment members  125 A. In selected embodiments, at least one of the arm joint members  125 B can comprise a rotary joint member, a rotational joint member and/or a prismatic joint member. A proximal arm segment member  125 A can be coupled with the positioning system base  128  directly or, as shown in  FIG.  2 A , via an arm joint member  125 B; whereas, a distal arm segment member  125 A can comprise an end effector member  125 C for coupling with the selected calibration target device  122 . 
     The sensor calibration system  100  advantageously incorporates a high degree of generalization and can support a wide range of calibration procedures. For instance, the sensor calibration system  100  can perform calibration procedures for a camera-based, RADAR-based and/or Lidar-based sensor systems  210 . The sensor calibration system  100  likewise can be programmatically controlled and/or perform calibration procedures for any device under test  200  associated with any brand, type or other identifying attribute. 
     As illustrated in  FIGS.  2 A-B , for example, the sensor calibration system  100  is shown as accommodating two different devices under test  200 A,  200 B, respectively. The first device under test  200 A can have a first sensor system  210 A that is different from a second sensor system  210 B of the second device under test  200 B. The first sensor system  210 A, for example, can have a first sensor type that is different from a second sensor type of the second sensor system  210 B. Additionally and/or alternatively, the first sensor system  210 A can be disposed at a first location of the first device under test  200 A; whereas, the second sensor system  210 B can be disposed at a second location of the second device under test  200 B. 
     The first sensor type of the first sensor system  210 A can necessitate selection of a first calibration target device  122 A with first calibration indicia  124 A. Similarly, the second sensor type of the second sensor system  210 B can necessitate of a second selected calibration target device  122 B with second calibration indicia  124 B. In selected embodiments, the calibration target positioning system  126  can arrange the first calibration target device  122 A at a first predetermined distance D A , elevation, orientation, angle and/or other position attribute relative to the first device under test  200 A and/or the first sensor system  210 A in the manner discussed in more detail above with reference to  FIG.  1   . 
     The first position attributes of the first calibration target device  122 A can be based, for example, upon the first sensor type and/or the first location of the first sensor system  210 A. The calibration target positioning system  126  likewise can arrange the second calibration target device  122 B at a second predetermined distance D B , elevation, orientation, angle and/or other position attribute relative to the second device under test  200 B and/or the second sensor system  210 B as set forth above. For instance, the second position attributes of the second calibration target device  122 B can be based upon the second sensor type and/or the second location of the second sensor system  210 B. The first and second predetermined distances D A , D B  can comprise any suitable predetermined distance. Exemplary predetermined distances can include one or more predetermined distances, such as fifteen hundred millimeters and three thousand millimeters, and/or at least one predetermined distance range, such as between fifteen hundred millimeters and three thousand millimeters, including any preselected distance subranges within a predetermined distance range, without limitation. 
     Returning to  FIG.  1   , one or more imaging systems (or circuits)  130  are shown as being disposed adjacent to the turntable system  110 . Exemplary imaging systems  130  can include, but are not limited to, a LiDAR imaging system (or circuit), a RADAR imaging system (or circuit) and/or a camera system (or circuit). In selected embodiments, the LiDAR imaging system can comprise a high-precision three-dimensional LiDAR imaging system and/or an industrial-grade two-dimensional LiDAR imaging system; whereas, the camera imaging system can include a high fidelity camera. The imaging systems  130  preferably comprise uniform imaging systems of the same type but, in selected embodiments, can include at least one imaging system of a different type. The calibration target system  120  and the imaging systems  130  can be distributed about a periphery of the turntable system  110  in any suitable manner. The imaging systems  130  can be disposed at respective predetermined distances, elevations, orientations, angles and/or other position attributes relative to the device under test  200  and/or sensor system  210 . 
     The turntable system  110  can rotate the device under test  200  and/or sensor system  210  relative to the calibration target system  120  and the imaging systems  130  during an extrinsic sensor calibration process. As desired, the turntable system  110  can rotate the device under test  200  and/or sensor system  210  about a central axis of rotation of the turntable system  110  in a clockwise direction and/or in a counter clockwise direction. The turntable system  110  likewise can rotate the device under test  200  and/or sensor system  210  through one or more full revolutions and/or can rotate the device under test  200  and/or sensor system  210  by a predetermined percentage of a revolution. The direction and/or amount of rotation can be based, at least in part, upon a requirement of the extrinsic sensor calibration process. In selected embodiments, the calibration target system  120  and/or the imaging systems  130  can remain static (or motionless) and/or dynamic (or in motion) as the turntable system  110  rotates the device under test  200  and/or sensor system  210 . 
     The extrinsic sensor calibration process preferably comprises an automated extrinsic sensor calibration process. The sensor calibration system  100  is shown in  FIG.  1    as included an optional control system (or circuit)  140  for controlling or otherwise automating the extrinsic sensor calibration process. For example, the control system  140  can be configured to control operation of the turntable system  110 , the calibration target system  120  and/or the imaging system  130 . The control system  140  can comprise a processing system (or circuit), such as a computer server system, a personal computing system, laptop computing system, tablet computing system, mobile telephone system or any other conventional type of processing system suitable for controlling the turntable system  110 , the calibration target system  120  and/or the imaging system  130 . Preferably, the control system  140  can include a high-precision controller and encoder system (or circuit) (not shown) and/or one or more on-board high clock-rate central processing units (CPUs) and/or graphics processing units (GPUs) with internet access. The extrinsic sensor calibration process, in selected embodiments, can comprise a computer-implemented extrinsic sensor calibration process. 
     The control system  140  can communicate with the turntable system  110 , the calibration target system  120  and/or the imaging system  130  in any conventional wired manner and/or wireless manner. The control system  140 , for example, can exchange data with the turntable system  110 , the calibration target system  120  and/or the imaging system  130  directly or via a computer network (not shown), such as the internet. As illustrated in  FIG.  3   , the control system  140  can include a turntable control system (or circuit)  142  for controlling operation of the turntable system  110 , a calibration target control system (or circuit)  144  for controlling operation of the calibration target system  120  and/or an imaging control system (or circuit) (not shown) for controlling the imaging system  130 . 
     The turntable control system  142 , for example, can include an optional high-precision controller and encoder system (or circuit)  142 A (shown in  FIG.  13   ) for recording encoder angles as the turntable system  110  rotates. The turntable control system  142 , the calibration target control system  144  and the imaging control system can comprise separate control systems and/or can be at least partially integrated into at least one combined control system. In selected embodiments, the control system  140  can include a control station for providing a user interface  148  for enabling a system operator or other system user (not shown) to interact with the sensor calibration system  100 . 
     As shown in  FIG.  3   , the sensor calibration system  100  can include the calibration target system  120  and a pair of imaging systems  130  disposed about the central turntable system  110 . The calibration target system  120  can comprise the robotic arm  125  with the selected calibration target device  122  being coupled with the end effector member  125 C. The imaging systems  130  are illustrated as including a first imaging system  130 A and a second imaging system  130 B. The first and second imaging systems  130 A,  130 B can be disposed in any suitable configuration relative to the calibration target system  120 . 
     The first imaging system  130 A, for instance, is shown as opposing the calibration target system  120  across the central turntable system  110 . In other words, the first imaging system  130 A and the calibration target system  120  can be disposed in a plane that comprises opposite ends of a diameter of the central turntable system  110  and passing through a center (or central region)  115  (shown in  FIG.  6 A ) of the turntable system  110 . The second imaging system  130 B can be disposed in a position that is normal to the plane of the first imaging system  130 A and the calibration target system  120 . Stated somewhat differently, the second imaging system  130 B and the first imaging system  130 A can define a right angle at the central region  115 , and/or the second imaging system  130 B and the calibration target system  120  can define a right angle at the central region  115 . 
     Although shown in  FIGS.  1 - 3    as comprising a single calibration target system  120  and a single imaging system  130  for purpose of illustration only, the sensor calibration system  100  can include any suitable number of calibration target systems  120  and/or any suitable number of imaging systems  130 . The calibration target systems  120  can comprise a first calibration target system  120  that can be the same as, or different from, a second calibration target system  120 . The first calibration target system  120 , for example, can be associated with a first selected calibration target device  122 A (shown in  FIG.  2 A ); whereas, the second calibration target system  120  can be associated with a second selected calibration target device  122 B (shown in  FIG.  2 B ) that is different from the first selected calibration target device  122 . 
     Additionally and/or alternatively, the imaging systems  130  can comprise a first imaging system  130 A (shown in  FIG.  3   ) that can be the same as, or different from, a second imaging system  130 B (shown in  FIG.  3   ). If the first imaging system  130 A comprises a first LiDAR system, for example, the second imaging system  130 B can include a second LiDAR system if the first and second imaging systems  130 A,  130 B are the same. In contrast, if the first and second imaging systems  130 A,  130 B are different, the second imaging system  130 B can include a RADAR system. 
     Although shown and described as comprising a central turntable  110  for rotating the device under test  200  and/or the sensor system  210  for purposes of illustration only, the sensor calibration system  100  can be configured to rotate the calibration target system(s)  120  and/or the imaging system(s)  130  about a stationary device under test  200  and/or sensor system  210  in selected embodiments. 
     In operation, the sensor calibration system  100  advantageously can perform an extrinsic calibration method on the sensor system  210 . An exemplary extrinsic calibration method  300  is illustrated in  FIGS.  4 A-B . The extrinsic calibration method  300  can include instruction for configuring and controlling the sensor calibration system  100 . In selected embodiments, the sensor calibration system  100  can be controlled and configured via software that can be executed by the control system  140  (shown in  FIG.  1   ). The extrinsic calibration method  300 , in other words, can comprise a computer-implemented extrinsic calibration method in selected embodiments. 
     Turning to  FIG.  4 A , the extrinsic calibration method  300  is shown as including, at  320 , configuring the sensor calibration system  100  (shown in  FIG.  1   ) for calibrating a sensor system  210  (shown in  FIG.  1   ) associated with a relevant device under test  200  (shown in  FIG.  1   ). The sensor system  210  of the device under test  200  can be calibrated, at  330 , via the configured sensor calibration system  100 . In selected embodiments, the extrinsic calibration method  300  can comprise an automated extrinsic sensor calibration process. The extrinsic calibration method  300 , in other words, can be controlled or otherwise automated via a processing system (or circuit) such as the control system  140  (shown in  FIG.  1   ). 
     An alternative embodiment of the extrinsic calibration method  300  is shown in  FIG.  4 B . As illustrated in  FIG.  4 B , the extrinsic calibration method  300  can include, at  310 , scanning a relevant device under test  200  (shown in  FIG.  1   ) that is associated with a sensor system  210  (shown in  FIG.  1   ). The sensor calibration system  100  can be configured, at  320 , for use with the scanned device under test  200 . In other words, the sensor calibration system  100 , at  320 A, can be configured for calibrating the sensor system  210  of the scanned device under test  200 . At  330 A, the sensor system  210  of the scanned device under test  200  can be calibrated via the configured sensor calibration system  100 . 
     The relevant device under test  200  can be scanned, at  310 , in any suitable matter. Turning to  FIG.  5 A , for example, the relevant device under test  200  can be scanned, at  312 , by positioning the device under test  200  at the turntable system  110  (shown in  FIG.  1   ). In selected embodiments, the relevant device under test  200  can be disposed on the testing region  112  (shown in  FIG.  1   ) of the turntable system  110 . As the turntable system  110  with the relevant device under test  200  rotates at a predetermined rotational speed, a three-dimensional image of the relevant device under test  200  can be captured, at  314 . The three-dimensional image of the relevant device under test  200  can be captured, at  314 , for example, can be captured via the imaging system(s)  130  (shown in  FIG.  1   ). 
     If the imaging system  130  includes a three-dimensional LiDAR imaging system, the turntable system  110  preferably can rotate at a low, fixed rotational speed for enabling the three-dimensional LiDAR imaging system to construct or otherwise capture a complete three-dimensional registered point cloud image  136  (shown in  FIG.  13   ) of the relevant device under test  200  as the relevant device under test  200  rotates with the turntable system  110 . Exemplary rotational speeds can include, but are not limited to, any rotational speed within a rotational speed range between one-twentieth of a rotation per second and ten rotations per second. In selected embodiments, the rotational speed can comprise a rotational speed within a rotational speed range between one-tenth of a rotation per second and four rotations per second. Capturing the three-dimensional registered point cloud image optionally can include capturing a sparse three-dimensional registered point cloud image of the rotated device under test  200  and/or capturing a dense three-dimensional registered point cloud image of the rotated device under test  200 . Any noisy points in the three-dimensional registered point cloud image  136  of the relevant device under test  200  optionally can be filtered. 
     At  316 , the relevant device under test  200  can be identified based upon the captured three-dimensional image of the relevant device under test  200 . The relevant device under test  200  can be identified, for example, by extracting one or more relevant markers or other device components  220  (shown in  FIG.  14   ) from the captured three-dimensional image of the relevant device under test  200 . Exemplary markers can include, but are not limited to, a bumper, a side-view mirror, a wheel center, an axle center, a vehicle logo, a vehicle thrust line, a door and/or a pillar if the relevant device under test  200  comprises a passenger vehicle. Based upon the extracted markers, a make, model and/or any other identifying (or attribute) device information of the relevant device under test  200  can be determined. Identifying sensor information, such as a sensor type and/or a sensor location, of the sensor system  210  optionally can be determined based upon the extracted markers, the identifying device information and/or the identified device under test  200 . 
     Once the relevant device under test  200  has been identified, the sensor calibration system  100  (shown in  FIG.  1   ), can be configured for the relevant device under test  200 , at  320 A (shown in  FIG.  4 B ). The sensor calibration system  100 , in other words, can be configured for calibrating the sensor system  210  of the scanned device under test  200 . As shown in  FIG.  5 B , for example, at least one calibration target device  122  (shown in  FIG.  1   ) can be selected, at  322 , for coupling with a calibration target positioning system  126  (shown in  FIG.  1   ) once the relevant device under test  200  has been identified. At  324 , the selected calibration target device  122  can be disposed at the calibration target positioning system  126  (shown in  FIG.  1   ). 
     The selected calibration target device  122 , in selected embodiments, can be coupled with the calibration target positioning system  126  in the manner discussed in more detail above with reference to  FIGS.  1  and  2 A-B . The calibration target positioning system  126  then can position, at  326 , the selected calibration target device  122  relative to the device under test  200  disposed at the turntable system  110 . In selected embodiments, the calibration target positioning system  126  can arrange the selected calibration target device  122  at the predetermined distance D, elevation, orientation, angle and/or other position attribute relative to the device under test  200  and/or sensor system  210  in the manner discussed in more detail above with reference to  FIGS.  1  and  2 A-B . 
     Returning briefly to  FIG.  4 B , the sensor system  210  of the scanned device under test  200  can be calibrated, at  330 A, after the selected calibration target device  122  has been selected and positioned. The control system  140  (shown in  FIG.  1   ), for example, can control or otherwise automate the extrinsic sensor calibration process. The control system  140  can be configured to control operation of the turntable system  110  (shown in  FIG.  1   ), the calibration target system  120   (shown in  FIG.  1   ) and/or the imaging system  130  (shown in  FIG.  1   ). In selected embodiments, the control system  140  can adjust at least one position attribute, a path plan and/or a speed of the calibration target system  120  during calibration, at  330 A, of the sensor system  210 . 
     Calibration data acquisition can be manually and/or automatically initiated at the device under test  200 . In selected embodiments, the calibration data for calibrating the sensor system  210  can be captured and/or stored at the device under test  200 . The calibration procedure for the sensor system  210  can be run in real time at the device under test  200  and/or can be uploaded for execution and validate at a later date. For example, the calibration procedure can be uploaded to the device under test  200  or to a separate data storage system (or circuit) (not shown) such as the cloud. Once the calibration procedure is completed, the device under test  200  can be removed from the turntable system  110 , and the sensor calibration system  100  can return to a default state. 
     Accordingly, the sensor calibration system  100  and/or the extrinsic calibration method  300  can perform extrinsic calibration or re-calibration, as needed, for the sensor system  210 . The sensor calibration system  100  and/or the extrinsic calibration method  300  can rapidly perform highly-precise, factory-level calibration of the sensor system  210  with minimal, if any, user intervention to restore and/or maintain optimal functionality. Advantageously, the sensor calibration system  100  and/or the extrinsic calibration method  300  can leverage high-precision calibration target systems  120  and imaging systems  130  for performing the calibration procedure for a wide range of sensor systems  210  and devices under test  200  in a very precise manner. 
     In selected embodiments, the sensor calibration system  100  can calibrate a sensor system  210  that is associated with a passenger vehicle, such as an automobile, truck or van. The sensor calibration system  100  of  FIGS.  6 A-B  is shown as being configured to calibrate the sensor system  210  (shown in  FIG.  1   ) that is associated with the passenger vehicle. Turning to  FIG.  6 A , the sensor calibration system  100  is shown including the calibration target system  120  and a pair of imaging systems  130  disposed about the central turntable system  110  in the manner described in more detail above with reference to  FIG.  3   . The calibration target system  120 , for example, can comprise the robotic arm  125  with the end effector member  125 C for coupling with the selected calibration target device  122  (shown in  FIG.  3   ). As illustrated in  FIG.  6 A , the imaging systems  130  can comprise a first imaging system  130 A and a second imaging system  130 B. The first and second imaging systems  130 A,  130 B, for example, can comprise LiDAR imaging systems and/or can be disposed in any suitable configuration relative to the calibration target system  120 . 
     The turntable system  110  is shown as having a testing region  112  with a predetermined diameter W T  for supporting, rotating or otherwise accommodating the passenger vehicle. The predetermined diameter W T  can be within a diameter range between one meter and ten meters, or more. In selected embodiments, the predetermined diameter W T  can be within a preselected diameter subrange of the diameter range, such as a preselected two-meter diameter subrange between four meters and six meters and/or a preselected four-meter diameter subrange between four meters and eight meters. The predetermined diameter W T  of the testing region  112  preferably can comprise a suitable dimension for accommodating a variety of passenger vehicles with different shapes, sizes and/or weights. 
     A periphery of the testing region  112  can be at least partially encircled or otherwise enclosed by a testing apron region  118 . In other words, the testing apron region  118  can be concentric relative to the turntable system  110  in selected embodiments. The testing apron region  118  can have a predetermined inner diameter that is substantially equal to or greater than the predetermined diameter W T  of the testing region  112  and a predetermined outer diameter W AC  that is greater than the predetermined inner diameter of the testing apron region  118 . A width of the testing apron region  118  can be within a range between one meter and ten meters, or more. In selected embodiments, the predetermined outer diameter W AC  of the testing apron region  118  can be within a preselected diameter subrange of the diameter range, such as a preselected four-meter diameter subrange between the predetermined inner diameter and the predetermined outer diameter W AC  of the testing apron region  118 . If the predetermined diameter W T  of the testing region  112  is six meters, the predetermined inner diameter of the testing apron region  118  can be approximately equal to six meters, and the predetermined outer diameter W AC  can be equal to twelve meters. 
     As illustrated in  FIG.  6 A , at least one calibration target system  120  and/or at least one imaging system  130  can be disposed within the testing apron region  118 . The calibration target system  120  and/or the imaging system  130  can be fixedly disposed on the testing apron region  118  in selected embodiments. The first imaging system  130 A is shown as being disposed on the testing apron region  118  opposite the calibration target system  120  across the turntable system  110 . In other words, the first imaging system  130 A and the calibration target system  120  can be disposed in a plane that comprises opposite ends of a diameter of the central turntable system  110  and passing through the central region  115  of the turntable system  110 . The calibration target positioning system  126  of the calibration target system  120  is shown as being placed a predetermined distance Wc from the central region  115  of the turntable system  110 ; whereas, the first imaging system  130 A is shown as being placed a predetermined distance W A  from the central region  115  of the turntable system  110 . 
     The second imaging system  130 B can be disposed within the testing apron region  118  in a position that is normal to the plane of the first imaging system  130 A and the calibration target system  120 . Stated somewhat differently, the first imaging system  130 A and the second imaging system  130 B can define a right angle at the central region  115 , and/or the calibration target system  120  and the second imaging system  130 B can define a right angle at the central region  115 . The second imaging system  130 B is shown as being placed a predetermined distance W B  from the central region  115  of the turntable system  110 . 
     In selected embodiments, the predetermined distance W A  between the first imaging system  130 A and the central region  115  can be equal to the predetermined distance W B  between the second imaging system  130 B and the central region  115 . The predetermined distance Wc between the calibration target system  120  and the central region  115  can be greater than, less than and/or equal to the predetermined distance W A  between the first imaging system  130 A and the central region  115  and/or the second imaging system  130 B and the central region  115 . If the predetermined diameter W T  of the testing region  112  is six meters, for example, at least one of the predetermined distances W A , W B , W C  can comprise a predetermined distance within a predetermined distance range of three meters and ten meters. In selected embodiments, the predetermined distances W A , W B , W C  can be within a preselected diameter subrange of the predetermined distance range, such as a preselected three-meter diameter subrange between three meters and six meters. 
     The calibration target system  120  is shown in  FIG.  6 B  as being disposed at a predetermined height H c  above the testing apron region  118 . In selected embodiments, the calibration target positioning system  126  of the calibration target system  120  can be disposed at the predetermined height H c  above the testing apron region  118 . The predetermined height H c  can comprise any suitable predetermined height for proper placement of the calibration indicia  124  relative to the passenger vehicle or sensor system  210  (shown in  FIG.  1   ). Exemplary predetermined heights H c  can include, but are not limited to, a height within the predetermined height range between zero meters and six meters. In selected embodiments, the predetermined height H c  can be within a preselected height subrange of the predetermined height range, such as a preselected one-meter diameter subrange between zero meters and one meter. 
     The first and second imaging systems  130 A,  130 B can be disposed at respective predetermined heights H A , H B  above the testing apron region  118 . As shown in  FIG.  6 B , the first and second imaging systems  130 A,  130 B can be respectively supported by first and second support members  132 A,  132 B that can be disposed within the testing apron region  118 . Each support member  132  can be fixedly disposed on the testing apron region  118  and configured to alternately couple with at least one selected imaging system  130  in selected embodiments. Stated somewhat differently, each support member  132  can couple with at least one of a plurality of imaging systems  130  of the same type and/or or different types. 
     The first and second predetermined heights H A , H B  can comprise any suitable predetermined height for proper placement of the respective first and second imaging systems  130 A,  130 B relative to the passenger vehicle or sensor system  210 . The first predetermined height H A  of the first imaging system  130 A can be the same as, and/or or different from, the second predetermined height H B  of the second imaging system  130 B. Exemplary first and second predetermined heights H A , H B  can include, but are not limited to, a height within the predetermined height range between zero meters and six meters. In selected embodiments, the first and second predetermined heights H A , H B  can be within a preselected height subrange of the predetermined height range, such as a preselected one-and-a-half-meter diameter subrange between one and a half meters and three meters. 
     Additionally and/or alternatively, the first and second imaging systems  130 A,  130 B can be disposed at respective first and second predetermined imaging angles Θ A , Θ B  relative to the testing region  112 . The first imaging system  130 A, for example, can be coupled with the first support member  132 A and adjusted to the first predetermined imaging angle Θ A ; whereas, the second imaging system  130 B can be coupled with the second support member  132 B and adjusted to the second predetermined imaging angle Θ B  as shown in  FIG.  6 B . The first and second predetermined imaging angles Θ A , ⊝ B  can comprise any suitable predetermined imaging angle for imaging the passenger vehicle or sensor system  210 . The first predetermined imaging angle Θ A  of the first imaging system  130 A can be the same as, and/or or different from, the second predetermined imaging angle Θ B  of the second imaging system  130 B. 
     Exemplary first and second predetermined imaging angles Θ A  can include, but are not limited to, an imaging angle within the predetermined imaging angle range between zero degrees and sixty degrees. In selected embodiments, the first and second predetermined imaging angle Θ A  can be within a preselected imaging angle subrange of the predetermined imaging angle range, such as a preselected thirty degree subrange between zero degrees and thirty degrees. Although shown as comprising downwardly-inclined imaging angles in  FIG.  6 B  for purposes of illustration only, the first predetermined imaging angle Θ A  and/or the second predetermined imaging angle Θ B  can comprise an upwardly-inclined imaging angle in selected embodiments. 
     Additionally and/or alternatively, the sensor calibration system  100  can be configured to perform stating sensor system calibration. The sensor calibration system  100 , in other words, can support a robotic implementation of static sensor calibration for the sensor system  210  and/or the device under test  200  as shown in  FIG.  7   . Turning to  FIG.  7   , the sensor calibration system  100  is shown as including the turntable system  110  for supporting and/or rotating the device under test  200  and/or the sensor system  210  and the calibration target system  120  being disposed adjacent to the turntable system  110 . The sensor calibration system  100  of  FIG.  7    is shown as comprising a robotic arm  125 . In selected embodiments, the robotic arm  125  can comprise an articulated robotic arm  125  with an end effector member  125 C in the manner shown and described with reference to  FIGS.  2 A-B . 
     As shown in  FIG.  7   , the robotic arm  125  can extend the end effector member  125 C up to a first elevation Y 1  above the positioning system base  128  and/or down to a second elevation Y 2  below the positioning system base  128 . Exemplary first elevations Y 1  can include, but are not limited to, a predetermined first elevation within a predetermined first elevation range between zero meters and three meters; whereas, the second elevations Y 2  can include a predetermined second elevation within a predetermined second elevation range between zero meters and the predetermined height H c (shown in  FIG.  6 A ). In selected embodiments, the first elevation Y 1  can comprise a predetermined first elevation of 1.786 meters; whereas, the second elevation Y 2  can comprise a predetermined second elevation of 0.720 meters. 
     Additionally and/or alternatively, the robotic arm  125  can extend the end effector member  125 C away from the turntable system  110  by a first distance X 1  and/or toward the turntable system  110  by a second distance X 2 . Exemplary first distances X 1  can include, but are not limited to, a predetermined first distances within a predetermined first distance range between zero meters and three meters; whereas, the second distance X 2  can include a predetermined second distance within a predetermined second distance range between zero meters and three meters. In selected embodiments, the first distance X 1  can comprise a predetermined first distance of 1.150 meters; whereas, the second distance X 2  can comprise a predetermined second distance of 1.450 meters. 
     The robotic arm  125  optionally can have between two and nine degrees of freedom and/or an effective range radius that is between zero meters and a sum of the first and second distances X 1 , X 2  and/or a sum of the first and second elevations Y 1 , Y 2 . Continuing with the above numerical example, the effective range radius of the robotic arm  125  can be between a half meter and three meters. A combined movement of the turntable system  110  and the robotic arm  125  advantageously can provide a hemispheric effect calibration reachable volume RV around the device under test  200  and/or the sensor system  210  as illustrated in  FIG.  7   . 
     The hemispheric effect calibration reachable volume RV with a predetermined diameter X RV . The predetermined diameter X RV  can be equal to the sum of the first and second distances X 1 , X 2  and/or the sum of the first and second elevations Y 1 , Y 2  in selected embodiments. Based upon the above numerical example, the predetermined diameter X RV  of the calibration reachable volume RV provided by the combined movement of the turntable system  110  and the robotic arm  125  can include a predetermined diameter within a predetermined diameter range between six meters and twelve meters. 
     In the manner discussed in more detail above with reference to  FIGS.  1  and  2 A-B , the calibration target system  120  can be associated with one or more calibration target devices  122 , wherein each calibration target device  122  can have calibration indicia  124  suitable for calibrating the device under test  200  and/or sensor system  210 . The calibration indicia  124  of the calibration target devices  122  can differ, for example, based upon a type of device under test  200  and/or sensor system  210  being calibrated. A suitable calibration target device  122  thereby can be selected based upon the type of device under test  200  and/or sensor system  210  being calibrated and, as shown in  FIGS.  8 A-B,  9 A-B and  10 A-B , can be removably coupled with the end effector member  125 C of the calibration target system  120  for calibrating the device under test  200  and/or the sensor system  210 . 
     The selected calibration target device  122  preferably can be easily coupled with, and/or removed from, the end effector member  125 C for facilitating rapid reconfiguration of the sensor calibration system  100  between extrinsic sensor calibration processes. The calibration target devices  122 , for example, can be disposed within a reachable area of the robotic arm  125  for permitting the robotic arm  125  to retrieve the selected calibration target device  122  for use during a calibration process and to stow the selected calibration target device  122  after the calibration process is complete. The selected calibration target device  122  can include any predetermined number and/or type of calibration indicia  124  that is suitable for calibrating the relevant sensor system(s)  210  (shown in  FIG.  1   ). The selected calibration target device  122 , for example, can include one or more different calibration indicia  124  based upon the device under test  200  and/or the sensor system(s)  210  to be calibrated. 
     If the sensor system  210  comprises a camera imaging system, the selected calibration target device  122  can include first calibration indicia  124 U suitable for calibrating the camera imaging system as shown in  FIG.  8 A . The selected calibration target device  122  alternatively can include second calibration indicia  124 V for calibrating the camera imaging system as illustrated in  FIG.  8 B . The selected calibration target device  122  optionally can include third calibration indicia  124 W suitable for calibrating a LiDAR imaging system as shown in  FIG.  9 A  if the LiDAR imaging system is disposed aboard the device under test  200  (shown in  FIG.  1   ) as the sensor system  210  (shown in  FIG.  1   ). The selected calibration target device  122  alternatively can include second calibration indicia  124 X for calibrating the LiDAR imaging system as illustrated in  FIG.  9 B . Additionally and/or alternatively, if the sensor system  210  (shown in  FIG.  1   ) comprises a RADAR imaging system, the selected calibration target device  122  can include fifth calibration indicia  124 Y suitable for calibrating the RADAR imaging system as shown in  FIG.  10 A . The selected calibration target device  122  alternatively can include sixth calibration indicia  124 Z for calibrating the RADAR imaging system as illustrated in  FIG.  10 B . 
     The sensor system  210  advantageously can be disposed at a suitable position relative to the selected calibration target device  122  of the calibration target system  120 . In other words, a rotation or other movement of the turntable system  110  and/or the calibration target system  120  can be controlled such that the device under test  200  and/or the sensor system  210  is disposed at a suitable position within the calibration reachable volume RV (shown in  FIG.  7   ) of the turntable system  110  and the calibration target system  120 . If the sensor system  210  is disposed at a front region  201  of the device under test  200 , the turntable system  110  can rotate the device under test  200  such that the front region  201  is adjacent to the calibration target system  120  as shown in  FIG.  11 A . The calibration target system  120  can adjust a position of the selected calibration target device  122  relative to the front region  201  of the device under test  200  and/or the sensor system  210 . The sensor calibration system  100  disposed at the front region  201  thereby can be disposed at a suitable position relative to the selected calibration target device  122  for enabling the sensor calibration system  100  to proceed with the calibration process. 
       FIG.  11 B  shows that the turntable system  110  can rotate the device under test  200  such that a side region  202  is adjacent to the calibration target system  120  if the sensor system  210  is disposed at the side region  202  of the device under test  200 . The calibration target system  120  can adjust a position of the selected calibration target device  122 , as needed, relative to the side region  202  of the device under test  200  and/or the sensor system  210 . The sensor calibration system  100  disposed at the side region  202  thereby can be disposed at a suitable position relative to the selected calibration target device  122  for enabling the sensor calibration system  100  to proceed with the calibration process. 
     If the sensor system  210  is disposed at a back (or rear) region  203  of the device under test  200  as illustrated in  FIG.  11 C , the turntable system  110  can rotate the device under test  200  such that the rear region  203  is adjacent to the calibration target system  120 . The calibration target system  120  can adjust a position of the selected calibration target device  122  relative to the rear region  203  of the device under test  200  and/or the sensor system  210 . The sensor calibration system  100  disposed at the rear region  203  thereby can be disposed at a suitable position relative to the selected calibration target device  122  for enabling the sensor calibration system  100  to proceed with the calibration process. In other words, the device under test  200  and/or the sensor system  210  can be disposed at a proper orientation relative to the selected calibration target device  122  regardless of a location of the sensor system  210  within the device under test  200  by controlling a positioning or other movement of the turntable system  110  and/or the calibration target system  120 . 
     An exemplary control system  140  for the sensor calibration system  100  is shown in  FIG.  12   . Turning to  FIG.  12   , the control system  140  is shown as including a sensor data capture and control system (or circuit)  143  that can communicate with a master control system (or circuit)  141 . The sensor data capture and control system  143  can receive point cloud image and other sensor data from each imaging system  130 . As shown in  FIG.  12   , the sensor data capture and control system  143  can receive first point cloud image and other sensor data from the first imaging system  130 A and/or second point cloud image and other sensor data from the second imaging system  130 B. The point cloud image and other sensor data received from the imaging systems  130  optionally can comprise synchronized point cloud image and other sensor data. The sensor data capture and control system  143  can provide one or more imaging control commands to the imaging control system (not shown) for controlling the positioning and/or operation of the respective imaging systems  130 . 
     Additionally and/or alternatively, the sensor data capture and control system  143  can communicate with the turntable control system  142  for controlling the positioning and/or operation of the turntable system  110  and/or the calibration target control system  144  for controlling the positioning and/or operation of the calibration target system  120 . The sensor data capture and control system  143 , for example, can provide one or more turntable control commands to the turntable control system  142  for controlling the orientation of the turntable system  110 . Similarly, the sensor data capture and control system  143  can provide one or more target control commands to the calibration target control system  144  for controlling the orientation and other positioning of the calibration target system  120 . 
     The sensor data capture and control system  143 , for example, can provide one or more turntable control commands to the turntable control system  142  for controlling the orientation of the turntable system  110 . If the calibration target system  120  comprises the robotic arm  125  with the end effector member  125 C for coupling with the selected calibration target device  122  (shown in  FIG.  3   ), the sensor data capture and control system  143  can provide a target control command to the calibration target control system  144  for commanding the robotic arm  125  to couple a selected calibration target device  122  to the end effector member  125 C and/or to move the end effector member  125 C to a predetermined position and/or orientation. 
     In selected embodiments, communication between the sensor data capture and control system  143  and the turntable control system  142  and/or the calibration target control system  144  can comprises bidirectional communication. The sensor data capture and control system  143  thereby can receive turntable feedback data from the turntable control system  142  and/or target feedback data from the calibration target control system  144 . Exemplary turntable feedback data can include, but is not limited to, a current orientation and/or rotational speed of the turntable control system  142 ; whereas, the target feedback data can comprise data with regard to whether a calibration target device  122  is currently coupled with the end effector member  125 C, identity information about any currently-coupled calibration target device  122  and/or a current position and/or orientation of the end effector member  125 C. Advantageously, the sensor data capture and control system  143  can utilize the received turntable feedback data to control the turntable system  110 . The sensor data capture and control system  143  likewise can utilize the received target feedback data to control the calibration target system  120 . 
     The sensor data capture and control system  143  is illustrated in  FIG.  12    as supporting bidirectional communication for exchanging data and commands with the master control system  141 . The master control system  141  can communicate with one or more other subsystems of the control system  140 . As shown in  FIG.  12   , for example, the master control system  141  can communicate with a three-dimension reconstruction system (or circuit)  145  for reconstructing the registered point cloud image  136  (shown in  FIG.  13   ) of the device under test  200  disposed on the turntable system  110  in the manner set forth above with reference to  FIG.  5 A . The three-dimension reconstruction system  145  advantageously can receive multiple measurements of the device under test  200  from different vantage points and can convert the received measurements into the registered point cloud image  136 . 
       FIG.  13    shows an exemplary three-dimension reconstruction system  145  of the control system  140 . Turning to  FIG.  13   , the three-dimension reconstruction system  145  is illustrated as comprising a point cloud registration system (or circuit)  160  for receiving turntable encoder angle data from the turntable system  110  (shown in  FIG.  1   ) and image frame data  134  from at least one imaging system  130  (shown in  FIG.  1   ). The image frame data  134  can comprise a sequence or other plurality of image frames  134   1 ,  134   2 , ...,  134   N . 
     As the turntable system  110  with the device under test  200  rotates, the high-precision controller and encoder system  142 A of the turntable control system  142  can record a sequence or other plurality of encoder angles of the turntable system  110  in the manner discussed above with reference to  FIGS.  1  and  3   . The high-precision controller and encoder system  142 A can provide the recorded encoder angles to the point cloud registration system  160 . In selected embodiments, the high-precision controller and encoder system  142 A can provide the recorded encoder angles to the point cloud registration system  160  via the sensor data capture and control system  143  (shown in  FIG.  12   ) and/or the master control system  141  (shown in  FIG.  12   ). The point cloud registration system  160  can receive the recorded encoder angles via a pose integration system (or circuit)  162 . In selected embodiments, the pose integration system  162  can comprise a rigid body pose integration system. 
     The imaging system  130  likewise can capture the image frame data  134  of the rotating device under test  200  at the turntable system  110 . Stated somewhat differently, the image frame data  134  can comprise a plurality of images of the device under test  200  captured by the imaging system  130  at respective different angles as the device under test  200  via the turntable system  110 . The imaging system  130  and/or the imaging control system associated with the imaging system  130  can provide the captured image frame data  134  to the point cloud registration system  160 . In selected embodiments, the imaging system  130  and/or the imaging control system can provide the captured image frame data  134  to the point cloud registration system  160  via the sensor data capture and control system  143  and/or the master control system  141 . The point cloud registration system  160  can receive the captured image frame data  134  via a rigid body (or RB) transform system (or circuit)  164 . 
     As illustrated in  FIG.  13   , the rigid body transform system  164  can comprise a plurality of rigid body transform subsystems 164 1 , 164 2 , ...,  164   N  for receiving a respective one of the image frames  134   1 ,  134   2 , ...,  134   N . The rigid body transform system  164  can integrate the recorded encoder angles from the pose integration system  162  with the captured image frame data  134  to produce a rigid body transform of the captured image frame data  134  for explaining the rotation or other motion of the turntable system  100 . More specifically, the first rigid body transform subsystem 164 1  can integrate a first recorded encoder angle from the pose integration system  162  with the first captured image frame data  134   1  to produce a first rigid body transform of the captured image frame data  134 . The second rigid body transform subsystem 164 2  can integrate a second recorded encoder angle from the pose integration system  162  with the second captured image frame data  134   2  to produce a second rigid body transform of the captured image frame data  134  and so on until the Nth rigid body transform subsystem  164   N  integrates an Nth recorded encoder angle from the pose integration system  162  with the Nth captured image frame data  134   N  to produce a Nth rigid body transform of the captured image frame data  134 . 
     The rigid body transforms of the image frames  134   1 ,  134   2 , ...,  134   N  can be combined, at  166 , and a transformed frame accumulation system (or circuit)  168  advantageously can transform and/or accumulate the combined rigid body transforms the image frames  134   1 ,  134   2 , ...,  134   N  into a preselected coordinate system. The transformed frame accumulation system  168  thereby can generate the three-dimensional registered point cloud image  136  of the device under test  200  in the preselected coordinate system. Stated somewhat differently, the three-dimensional registered point cloud image  136  can comprise a dense point cloud image of the device under test  200  in a chosen coordinate frame of reference. Any noisy points in the three-dimensional registered point cloud image  136  of the device under test  200  optionally can be filtered. 
     Returning briefly to  FIG.  12   , the master control system  141  optionally can communicate with a machine learning system (or circuit)  146  for deciphering one or more aspects and/or segments of the device under test  200  disposed on the turntable system  110 . The machine learning system  146  can extract one or more device parts, features, markers or other device components  220  of the device under test  200  as illustrated in  FIG.  14   . If the device under test  200  comprises a passenger vehicle as shown in  FIG.  14   , exemplary device components  220  of the passenger vehicle can include, but are not limited to, at least one vehicle mirror  222 , at least one vehicle bumper  224 , at least one vehicle wheel  226  (or a center of the vehicle wheel  226 ), at least one vehicle thrust line, at least one vehicle door and/or at least one vehicle pillar. The machine learning system  146  of  FIG.  14    is shown as extracting left and right sideview mirrors  222 L,  222 R, front and rear bumpers  224 F,  224 R and/or centers of left front, right front and right rear wheels  226 LF,  226 RF,  226 RR. 
     The machine learning system  146  can extract the device components  220  of the device under test  200  in any suitable matter. As illustrated in  FIG.  14   , for example, the machine learning system  146  can extract the device components  220  based upon the three-dimensional registered point cloud image  136  of the device under test  200 . In selected embodiments, the machine learning system  146  can comprise a neural network-based machine learning framework (not shown) that previously has been trained on data for a plurality of passenger vehicles and other types of devices under test  200 . The training data can include one or more component labels that are associated with respective device components  220  for each of the passenger vehicles and other types of devices under test  200 . Stated somewhat differently, each device under test  200  in the training data can include at least one device component  220  that has been associated with a respective label. 
     The neural network-based machine learning framework enable a neural network inference to be run on the three-dimensional registered point cloud image  136  of the passenger vehicle. Based upon the neural network inference, the neural network-based machine learning framework can compare the three-dimensional registered point cloud image  136  with the labelled training data. The neural network-based machine learning framework, in other words, can identify a known passenger vehicle having a collection of labelled device components  220  within the labelled data that best matches the extracted device components  220  of the passenger vehicle depicted by the three-dimensional registered point cloud image  136 . Thereby, the neural network-based machine learning framework can identify and localize one or more device components  220  of the passenger vehicle within the three-dimensional registered point cloud image  136 . 
     Returning again to  FIG.  12   , the master control system  141  optionally can communicate with a robot and turntable path planning system  147  for solving forward and inverse kinematics of the turntable system  110  and the calibration target system  120 . The robot and turntable path planning system  147  advantageously can control a movement of the turntable system  100  and the calibration target system  120  into desired orientations and/or positions while avoiding any collision with the device under test  200  at the turntable system  110  or any other object in a sensor calibration environment in which the sensor calibration system  100  is disposed. Stated somewhat differently, the robot and turntable path planning system  147  can avoid a movement path of the calibration target system  120  that could lead to a collision between the selected calibration target device  122  (shown in  FIG.  3   ) or the calibration target positioning system  126  (shown in  FIG.  3   ) and the device under test  200  as oriented on the turntable system  110  or any other object in the sensor calibration environment. 
     The master control system  141  is illustrated as communicating with the user interface  148  for enabling the system operator or other system user (not shown) to interact with the sensor calibration system  100 . The master control system  141 , for example, can enable the system user to provide instruction to the sensor calibration system  100 . Exemplary instructions can include, but are not limited to, instruction for configuring the sensor calibration system  100  to perform an extrinsic sensor calibration process for the device under test  200  (shown in  FIG.  1   ) and/or the sensor system  210  (shown in  FIG.  1   ), instruction for initiating the extrinsic sensor calibration process and/or instruction for terminating the extrinsic sensor calibration process. The instruction for configuring the sensor calibration system  100  can comprise instruction for selecting the selected calibration target device  122  (shown in  FIG.  3   ) for disposal on the calibration target positioning system  126  (shown in  FIG.  3   ) and/or instruction for coupling the selected calibration target device  122  with the calibration target positioning system  126 , without limitation. In selected embodiments, the user interface  148  can visually and/or audibly present one or more results of the extrinsic sensor calibration process. The user interface  148  optionally can present diagnostic information associated with the extrinsic sensor calibration process. 
     As shown in  FIG.  12   , the master control system  141  optionally can communicate with a target placement simulator system (or circuit)  149 . The target placement simulator system  149  advantageously can aid in designing extrinsic sensor calibration process procedures for specific types of devices under test  200  and/or sensor systems  210 . For example, the target placement simulator system  149  can provide at least one tool  149 A for disposing one or more virtual calibration target devices  122 V around a virtual device under test  200 V that is associated with a virtual sensor system  210 V as illustrated in  FIG.  15   . The virtual device under test  200 V and/or virtual sensor system  210 V can be very similar to an actual (or physical) device under test  200  (shown in  FIG.  1   ) and/or sensor system  210  (shown in  FIG.  1   ) intended for undergoing an extrinsic sensor calibration process. In other words, the virtual device under test  200 V can comprise a model of the actual device under test  200 ; whereas, the virtual sensor system  210 V can comprise a model of the actual sensor system  210  intended for undergoing an extrinsic sensor calibration process. 
     The target placement simulator system  149  advantageously can present or otherwise provide a virtual sensor calibration environment for the actual device under test  200  and/or sensor system  210 . The tool  149 A advantageously can enable the system user to design the virtual sensor calibration environment by establishing and/or adjusting a number, selection, position and/or orientation of the virtual calibration target devices  122 V. As desired, the sensor calibration system  100  can precisely replicate the virtual sensor calibration environment via the actual turntable system  110  (shown in  FIG.  1   ) and one or more calibration target systems  120  (shown in  FIG.  1   ) for performing the extrinsic sensor calibration process on the actual device under test  200  and/or sensor system  210  in the actual sensor calibration environment. 
     Stated somewhat differently, the number, selection, position and/or orientation of the virtual calibration target devices  122 V can be transferred to the calibration target systems  120 . In selected embodiments, the robot and turntable path planning system  147  (shown in  FIG.  12   ) can control a movement of the turntable system  100  and/or the calibration target system  120  into the desired orientations and/or positions in the manner discussed in more detail above with reference to  FIG.  12   . The tool  149 A optionally can comprise a computer-implemented tool that is presented or otherwise provided via a processing system (or circuit)  149 B, such as a computer server system, a personal computing system, laptop computing system, tablet computing system, mobile telephone system or any other conventional type of suitable processing system. 
     Although shown and described with reference to  FIG.  12    as comprising separate systems for purposes of illustration only, one or more of the master control system  141 , the turntable control system  142 , sensor data capture and control system  143 , the calibration target control system  144 , the imaging control system, the three-dimension reconstruction system  145 , the machine learning system  146 , the robot and turntable path planning system  147 , the user interface  148  and/or the target placement simulator system  149  can be completely or at least partially integrated into a composite system, as desired. 
     Although selected embodiments of the sensor calibration system  100  and/or the extrinsic calibration method  300  have been set forth herein with reference to certain numerical values and/or numerical value ranges, it will be appreciated that the numerical values are provided for purposes of illustration only and not for purposes of limitation. The numerical values and/or numerical value ranges that are associated with selected features of the sensor calibration system  100  and/or the extrinsic calibration method  300  can depend upon a particular application of the sensor calibration system  100  and/or the extrinsic calibration method  300 , such as by being based upon the weight, size, diameter, shape and/or other characteristic of the device(s) under test  200  to be accommodated. It also will be appreciated that the numerical values and/or numerical value ranges in some cases can be outside of the recited predetermined ranges and/or inside of the preselected subranges within the predetermined ranges. 
     In selected embodiments, one or more of the features disclosed herein can be provided as a computer program product being encoded on one or more non-transitory machine-readable storage media. As used herein, a phrase in the form of at least one of A, B, C and D herein is to be construed as meaning one or more of A, one or more of B, one or more of C and/or one or more of D. Likewise, a phrase in the form of A, B, C or D as used herein is to be construed as meaning A or B or C or D. For example, a phrase in the form of A, B, C or a combination thereof is to be construed as meaning A or B or C or any combination of A, B and/or C. 
     The disclosed embodiments are susceptible to various modifications and alternative forms, and specific examples thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the disclosed embodiments are not to be limited to the particular forms or methods disclosed, but to the contrary, the disclosed embodiments are to cover all modifications, equivalents, and alternatives.