Adaptive Fuzzy Terminal Sliding-Mode Controller Design for Omni-Directional Mobile Robots

In this paper, we propose an adaptive fuzzy terminal sliding-mode control (AFTSMC) scheme for trajectory control of a tri-wheel omni-directional mobile robot (ODMR) with system uncertainties and external disturbances. The basic kinematic model of the ODMR is obtained simply from kinematics. Based on the Newton's Second Law of Motion, the dynamic model of the ODMR is then derived in detail. This control scheme combines the techniques of adaptive control, fuzzy logic control (FLC), sliding-mode control (SMC), and terminal attractor theory which can drive the error states to zero in finite time and the error rate states also can be converged to zero in finite time identically. The switching law is introduced to cope with the system uncertainties and external disturbances. The Lyapunov stability theory is adopted to verify the stability of the controlled system which can ensure the convergence of trajectory tracking errors to zero in finite time. All the simulation results demonstrate the effectiveness of the proposed control method.