Abstract: The operating environment of space robotic arms is time-varying and uncertain, and there exists the risk of damage caused by excessive contact force, which poses a challenge to the compliance of robotic arm operation. Firstly, in order to solve the problem that constant admittance control relies on accurate estimation to realize force tracking in the time-varying uncertain contact environment, an adaptive variable admittance control is researched for 6DOF robotic arm in this paper. Secondly, in order to solve the problem of excessive overshoot of adaptive variable admittance control, a fuzzy system for compensating the parameters of the adaptive strategy is designed and an adaptive fuzzy variable admittance control method is proposed. Based on three types of time-varying environments, the simulations are carried out to verify the effectiveness of the adaptive fuzzy variable admittance control algorithm via Matlab/Simulink. The simulation results show that the proposed adaptive fuzzy variable admittance coutrol has better comprehensive effects of force tracking and over shoot suppression in time-varying contact environments.

Key words: robotic arm, variable admittance control, adaptive strategy, fuzzy system