Fuzzy adaptive hybrid impedance control for mirror milling system

In this paper, a fuzzy adaptive hybrid impedance control scheme designed for the supporting side of mirror milling system is proposed, which is capable of solving the force supporting problem with time-varying environment stiffness. In the process of milling large thin-walled sides, maintaining a constant supporting force is crucial both for suppressing vibration and for reducing deformation. Moreover, a superior impedance control scheme is beneficial in terms of enhancing the system stability, which is characterized by easy-implementation in the industrial robots. Hence, the force error triggered by the time-varying stiffness environment can be compensated by using our fuzzy adaptive algorithm. Simulations are tested on a parallel robot, i.e., Tricept, in order to verify the force control accuracy as well as its robustness in terms of a time-varying stiffness environment. Both the simulation and the experiment show that our proposed support scheme has a better performance on maintaining the desired contact force than hybrid impedance (HI) control and adaptive hybrid impedance (AHI) control.