Robust force control by estimation of environment

Abstract

We propose a new force control strategy which is robust against disturbance and parameters variation. This method U an expansion of disturbance observer which estimates disturbance and parameters variation of motors with simple computation. The new observer also estimates disturbance and parameters variation of environment on which the force is imposed. Since they are compensated by the new observer, similar force response to the force command is realized. The effectiveness of the proposed method is confirmed by some experimental results.

Force‐based disturbance observer for dynamic force control and a position/force hybrid controller

“…However, they considered only constant force regulation and not dynamic force tracking. Komada et al proposed a force controller that exploited the impedance of the environment [14]. However, estimating the impedance is practically very difficult.…”

Adaptive robust force control by disturbance observer

“…We have also proposed a force control strategy using controller of the second derivative of force [7] [8][1O]. It is different from conventional force controllers [1][4] [6], because it is based on the second derivative of force.…”

“…In order to realize the robust force control, the change of the environment should also be considered. To compensate the parameter variations of environment, we have developed a new observer which estimates the disturbance due to the pa rameter variations of environment, and is termed environment observer [7][8J. The proposed strategy is combination of the dis turbance observer which estimates the disturbance and the pa rameter variations of the actuator, and the environment observer which estimates the parameter variations of the environment.…”

“…The proposed strategy is combination of the dis turbance observer which estimates the disturbance and the pa rameter variations of the actuator, and the environment observer which estimates the parameter variations of the environment. We have also proposed another robust strategy which is based on force-based disturbance observer which has the similar function to the former two observers [7][8].…”

“…The proposed strategy is combination of the dis turbance observer which estimates the disturbance and the pa rameter variations of the actuator, and the environment observer which estimates the parameter variations of the environment. We have also proposed another robust strategy which is based on force-based disturbance observer which has the similar function to the former two observers [7][8].0-7803-0582-5 ,'12$3.00©1992 IEEE Since the control system is fixed to a nominal system by the observers, second derivative of force can be controlled, and quick force response can be obtained. We have also proposed a force control strategy using controller of the second derivative of force[7][8][1O].…”