Fault tolerant consensus of multiple nonholonomic chained-form systems with actuator and communication faults

This article investigates the fault tolerant consensus problem of multiple nonholonomic chained-form systems with both actuator and communication faults. The systems are enabled to follow a reference trajectory and realize practical consensus, by applying distributed reference state observers and robust adaptive fault tolerant control (FTC) strategies. The proposed state observers are robust to communication faults and can estimate the actual reference trajectory for each system. Based on such an observer, a robust adaptive FTC scheme is further provided to address actuator faults. A sine function is injected into the FTC law to relax the persistent excitation condition to avoid uncontrollability of the two-input chained-form system when one of reference control input tends to zero. Simulation result of wheeled mobile robots shows the effectiveness of proposed FTC methods.