Actuator Fault Estimation Design for DC Motor Using Unknown Input Observer

This study investigates the problem of robust fault estimation for direct current (DC) motor control systems subjected to actuator faults and unknown input disturbances. An augmented descriptor system is first built by creating an augmented state consisting of system states and actuator faults. Then, a novel unknown input observer (UIO) based on the augmented descriptor system is proposed to estimate actuator faults by decoupling the unknown input disturbances. Furthermore, the design conditions of the observer are transformed into linear matrix inequalities (LMIs). Finally, the effectiveness of the developed UIO is validated through simulations.