Fuzzy sliding mode control for robotic manipulators based on passivity theory

Aiming at the model uncertainties and external disturbances of the robotic systems, First regard the exterior disturbances as system input, with skew-symmetric characteristics of the robot, this paper designed a controller based on the theory of passivity, and then used the classic sliding mode control to compensate the uncertainties´ influence. In order to eliminate chattering of sliding mode controller, the fuzzy control method was introduced, in which the sliding surface was regarded as the input of fuzzy controller while the output was the weight of compensation controller. Afterwards, proposed controllers were used in trajectory control of a two degrees of freedom robot. The simulation results show that the controllers can achieve tracking effect with high speed, guarantee asymptotic convergence of the tracking error to zero and enhance the robustness of the system.