Robust trajectory-tracking for nonholonomic wheel mobile robots using a PSO-tuned control approach

This paper addresses the trajectory-tracking problem for nonholonomic wheeled mobile robots subjected to model uncertainties and unknown external disturbances. In contrast to existing approaches that concentrate primarily on the kinematic control loop, this paper adopts a hierarchical control structure for the wheel mobile robot, including an outer kinematic loop and an inner dynamic loop. For the dynamic control loop, a dynamic controller combining integral terminal sliding mode control and a disturbance observer is developed to achieve disturbance rejection and chattering reduction. For the kinematic control loop, the kinematic controller is designed for accurate trajectory tracking control. Based on the Lyapunov stability theory, the stability analysis is given for both the disturbance observer and the double-loop tracking controller. Furthermore, the Particle Swarm Optimization algorithm is employed to optimize the control gains, thereby enhancing the overall performance of the control system. The simulation result using MATLAB software is conducted to confirm the effectiveness of the proposed method.