Control Using Joint Torque Sensor of Robot Arm with Two-Inertia Resonance

Abstract

Most Industrial robots are driven through reduction gears such as harmonic drives and RV gears. Since the flexibility of the drive system, the vibratory behavior is caused during the operation. When the flexibility is considered, the drive system of the robot joint can be modeled as a resonant mechanical system called two-inertia system. Conventionally, studies on two-inertia system discussed semi-closed loop control using only motor information and state observer. On the other hand, joint torque sensing of robots are studied on harmonic drives, which are used in robot joint widely. The joint torque sensor is becoming available with higher performance. In this paper, we consider the control of robot arm having two-inertia resonance by using joint torque sensor. The performances between torque sensor and obserber are compared.