A geometric approach for kinematic identification of an industrial robot using a monocular camera

We propose a generic formulation to identify the kinematic parameters of an industrial robot using a geometric approach when no prior information about the robot's kinematics is available. The joint axes were estimated using the singular value decomposition applied to the pose data of the robot's end-effector. These data were obtained by actuating one joint of the robot at a time. The approach is first illustrated using the CAD model of the robot. Next, a simulation study was performed to decide on the number of data points and angular actuation required by a revolute joint to estimate the kinematic parameters. This was done considering the fact that there exist noise in the measurements from the sensors. In this paper, we used a monocular camera mounted on the end-effector of an industrial robot KUKA KR5 Arc as the measurement sensor. We used ArUco Marker maps instead of a single calibration grid to enhance the range of actuation for each joint that was otherwise restricted due to the Field of View of the camera. The robot's kinematic parameters were then identified using the proposed approach. The identified parameters using the monocular camera were compared with those obtained using other measurement devices, namely, a total station and a laser tracker.