Force control including contact process using acceleration-sensor-based instantaneous state observer for high-stiffness gear drive

Abstract

This paper proposes a force control system including contact process using acceleration-sensor-based instantaneous state observer for high-stiffness gear drive. The proposed system is structured by PI velocity control system and IP force control system based on resonance ratio control system. An instantaneous state observer is used to a resonance ratio control system for a high-stiffness gear drive. In proposed system, the robot arm of a high-stiffness gear drive is achieved to move closer to the environment by using PI velocity control system. Moreover, the robot arm is achieved to come in contact with the environment by using IP force control system. Additionally, the force control system including contact process is needed a smooth switching of these control system, and smooth force control. To achieve the smooth switching of control system, an initial value of an integrator of force control system is calculated by the condition that a motor-side torque reference is constant when switching the control system. In addition, the algorithm is proposed to achieve the smooth force control system. The proposed method is achieved the smooth switching of control system and smooth force control system. The effectiveness of proposed method is confirmed by numerical simulation and experiments.