On the Dynamic Parameter Identification of Collaborative Manipulators: Application to a KUKA iiwa

This paper deals with the dynamic parameter identification of the KUKA LBR iiwa R820, a robotic manipulator with flexible joints intended for collaborative applications. The control software interface of this robot provides different signals that allow the parameter identification of not only the real robot, but also of the model integrated in the robot's controller, in a reverse engineering process. By analyzing the successive positions and torques computed by the controller, an accurate set of inertial parameters referring to the robot's model integrated in the controller is obtained. A percent error in the torque reconstruction of less than 1% for every joint, validates the process. Then, this set of parameters is useful to complete and compare the set of parameters that is obtained with real physical measurements which is more prone to errors due to noise and uncertainties. Finally, the torque reconstruction using the measured signals is compared with models present in bibliography, showing a better performance.