Adaptive fault-tolerant control of mobile robots with actuator faults and unknown parameters

This study deals with the fault-tolerant control problem for a class of two independent wheeled mobile robot systems with actuator faults and unknown robot parameters. Partial loss of control effectiveness and bias-actuator faults are addressed without knowing eventually faulty information of actuators. Adaptive schemes are developed to estimate unknown faulty parameters of actuator faults and unknown robot parameters of viscous friction factor and driving gain. Then, the backstepping control technique is utilised to construct the state feed-back control strategy based on the adaptive estimations. By using the Lyapunov stability theory, it is shown that the forward speed and azimuthal angle of wheeled mobile robots can track the given trajectory asymptotically in the case of actuator faults and unknown parameters. The effectiveness of the proposed designs is illustrated via a mobile robot system.