Adaptive sliding mode control for a mobile robot

Sliding mode control for wheeled mobile robots can be used due to their nonlinear dynamics and uncertainty. However، sliding mode control has the chattering problem and difficulties in finding the bounds of uncertainty which degrade the control performance. To improve the performance، this paper presents adaptive sliding mode control. The novelty includes a novel state-space model and using the voltage control strategy. The controller considers the motor dynamics whereas the previous approaches did not consider it by using torque control strategy. In the proposed design، the bounds of uncertainty are determined adaptively. As a result، the chattering problem is reduced. The proposed approach is based on the Lyapunov theory، thereby guarantees the stability of control system. In addition، the particle swarm optimization for finding the optimal design parameters is used. The proposed control approach is robust against the external disturbances and unmodeled dynamics. Simulation results show the superiority of the adaptive sliding mode control over the conventional sliding mode control.