Sensorless Force Control Based on H^∞ Control Theory

Abstract

This paper proposes the new force control without force sensor. The proposed system is designed by H^∞ control theory. Generally, The force sensor is usually used on the force control system. However, according to both the performance of force sensor and the condition of target environment, the force sensor can not be mounted to the robot manipulator.
Acceleration controller based on the disturbance observer has been studied to overcome the problem of force disturbance and nonlinear effect. However, it is difficult for this system to take account of the frequency characteristics of both sensor noise effect and disturbance rejection systematically. This paper proposes the new acceleration controller and the torque observer based on H^∞ control theory. These proposed systems are systematically designed by the mixed sensitivity H^∞ control design method. These systems have a simple and robust structure.