Self-Tuning Backstepping and Sliding Mode Control for Robust Trajectory Tracking in Differential Drive Wheeled Mobile Robots

This paper proposes a robust trajectory tracking control of a differential drive-wheeled mobile robot (DDWMR) with a unicycle model. A Lyapunov-based kinematic backstepping controller is developed to determine the necessary angular and linear velocities for the robot to move along the reference trajectory, considering only the kinematics of the robot. The velocity command generated by the kinematic controller is then passed to a dynamic controller. A sliding mode controller (SMC) is employed as the dynamic controller, providing robustness against external disturbances and variations in parameters. An adaptive law is implemented to self-tune the controller gains, ensuring accurate tracking of the reference trajectory. The stability of the closed-loop system is analyzed using the Lyapunov stability theory. Simulation results compared with a proportional integral derivative (PID) based dynamic controller demonstrate the robust performance of the proposed controller for trajectory tracking.