Robust Fuzzy Control of Electrical Manipulators

Stability analysis for fuzzy control of robot manipulators has been a serious challenging problem in literature. The theoretical difficulties are highly increased due to the complexity of both manipulator dynamics and fuzzy controller structure. This paper develops a novel robust fuzzy control approach for electrical robot manipulators using the direct method of Lyapunov. We pass analytical difficulties by the use of voltage control strategy in replace of torque control strategy. Then, a normalized and decentralized Takagi-Sugeno fuzzy controller is presented in a simple structure. A simple Lyapunov candidate is proposed to apply stability analysis without knowing the explicit dynamics of system. Consequently, fuzzy control is analyzed and designed as a robust nonlinear control. Roles of scaling factors, gains in consequent parts, and membership functions in condition parts are considered in the control design. The proposed control approach is applied on a Puma560 robot arm.