Gravity Compensation of KUKA LBR IIWA Through Fast Robot Interface

In this paper KUKA's Fast Robot Interface (FRI)is applied to design and implement a torque control with gravity compensation for the direct teching task on the KUKA LBR IIWA. We seek torque control method with more accurate gravity compensation to replace the original KUKA internal controller with a large compensation error. In order to accurately compensate the gravity of robot, this paper proposes a method of parameter identification based on QR decomposition and least squares theory and completes the parameter identification process. Then, the desired torque generated by accurate gravity compensation is delivered to the torque controller via FRI. The accuracy of gravity compensation results is verified by experiments.