Adaptive Fuzzy Output Feedback Control of a Nonholonomic Wheeled Mobile Robot

Abstract

This paper addresses the output feedback trajectory tracking problem for a nonholonomic wheeled mobile robot in the presence of parameter uncertainties, external disturbances, and a lack of velocity measurements. An unknown function is approximated by the fuzzy logic system, and an adaptive fuzzy observer is introduced. Then, by combining the kinematic model with the dynamic model, a control strategy is proposed that integrates an auxiliary velocity controller with an integral terminal sliding mode controller. By applying the proposed control strategy, it is proven that all of the signals in the closed system are bounded and that the auxiliary velocity tracking errors converge to a neighborhood of the origin in finite time. Therefore, the tracking position errors converge asymptotically to a small neighborhood near the origin with a faster response than achieved by other existing controllers. The simulation results demonstrate the effectiveness of the proposed strategy.

Keywords

• Wheeled mobile robot
• adaptive fuzzy control
• output feedback control
• finite time convergence