Fault Diagnosis Method Utilizing Actuator Redundancy and Identicalness With Applications to Electric Vehicles

This paper presents a fault diagnosis approach for a class of over-actuated systems where the actuators share the same unknown parameters. With the persistence of excitation condition being satisfied, the estimated unknown parameters from all the healthy and identical actuators should have a great similarity. A significant parameter estimation difference from other estimations may be attributed to the fault on the specific actuator. Such a feature was utilized to design the residuals and evaluate the actuator fault for over-actuated systems with identical actuators and applied to a four wheel independently actuated (FWIA) electric ground vehicle where the tire-road friction coefficient (TRFC) can be treated as the common unknown parameter for the four wheels. Simulation and experimental results from a FWIA electric ground vehicle are given to show the effectiveness of the proposed fault diagnosis method.