Load-side acceleration control for industrial robot arm with axial torsion

This paper proposes a new acceleration control method for industrial robots. To achieve high-speed and high-precision path tracking control, the motion control system must be able to control the arm acceleration. However, it is difficult to directly control the arm acceleration, because the speed reduction mechanism of industrial robots has axial torsion. To solve this problem, this paper proposes a new acceleration control method based on an inverse system. The proposed method designs an inverse transfer function system from the current command for arm acceleration. Acceleration control is achieved by the feed-forward control input designed from the inverse system. In addition, a robust feedback control system is designed to compensate for the dynamic disturbance torque and parameter variation. The effectiveness of the proposed method is confirmed by experimental results using a 2-DOF robot manipulator.