Fuzzy Control of an Uncertain Robot Manipulator with Input Constraint

Abstract

In this paper, an adaptive fuzzy dynamic surface control scheme is proposed for an uncertain n-link robot manipulator with input saturation. The fuzzy logic system is used to approximate the uncertain dynamics of the robotic manipulator. Also, a hyperbolic tangent function-based saturation model and mean value theorem are employed to design the proposed scheme based on the dynamic surface control approach. Stability analysis of the proposed approach guarantees that all signals of the closed-loop system are semi-globally uniformly ultimately bounded. Simulation results on an uncertain 2-joint robot manipulator verify the ability of the proposed approach to deal with both the saturation nonlinearity and uncertain dynamics.