Independent Joint Adaptive Fuzzy Control of Robot Manipulator

Abstract Control of multi-link robot arms is a challenging and difficult problem because of the highly nonlinear dynamics. An Independent joint adaptive scheme based on fuzzy logic is developed for control of robot manipulators. Fuzzy logic system aze used to approximate the uncertainties of functions; such as, coupling forces among the each joints, Coriolis force, centrifugal force, gravitational force, and frictional forces. A compensation controller is also proposed to estimate the bound of approximation error so that the chattering effect of the control effort can be reduced. The free parameters of the adaptive fuzzy control can be tuned on-line based on a Lyapunov synthesis approach. Thus the asymptotic stability of the closed-loop control system can be obtained. The proposed scheme does not require an accurate manipulator dynamic model. Numerical simulations results for athree-axis robot manipulator aze included to show the effectiveness of proposed controller.