Adaptive Force Tracking Control of Manipulator in Uncalibrated Varied Environment Based on Variable Impedance Control

Abstract

Manipulators usually need to contact with environment when executing polishing, grinding, welding and other tasks. Maintaining the stable contact force is crucial to the successful execution of the mission. However, the traditional constant impedance control algorithm connot track desired force if the environment information is unknown. This paper presents a new variable impedance control algorithem is proposed based on force feedback. An adaptive control law is used to adjust the damping parameters of variable impedance control algorithm. Environmental location estimation error can be compensated by adaptive impedance control law. The algorithm is very simple which only need the force sensor to detect the end-effertor contact force. Routh criterion is used to analysed stability of the admittance controller. To verifying the effectiveness, a series of simulations were carried out. Small force tracking errors can be achieved with the proposed algorithm.