Adaptive Fuzzy Computed-Torque Control for Robot Manipulator with Uncertain Dynamics

To overcome the disadvantages of conventional computed‐torque control and fuzzy control, and to exploit their attractive features, this paper proposes two types of adaptive control scheme combining conventional computed‐torque control and different fuzzy compensators for the robust tracking control of robotic manipulators with structured and unstructured uncertainties. Fuzzy compensators based on feed‐forward and feed‐back are developed to compensate these uncertain dynamics. On the basis of Lyapunov stability theory, a tracking error limit is derived for the closed‐loop control system and the convergence and stability of the control schemes are proved. Comparisons of their performances with conventional computed‐torque controllers under the condition of these uncertainties are carried out. The validity of the two types of adaptive control scheme is shown by numerical simulations of a three‐link rotary robot manipulator.