Diagnosis of sensor faults in active magnetic bearing system equipped with built-in force transducers

In this paper, an on-line diagnosis scheme for sensor faults in an active magnetic bearing system equipped with built-in force transducers is proposed. The scheme, utilizing redundant signals, i.e., displacement, current, and force, is based on the causality between faults and symptoms. The main advantage of the scheme is that it is simple and efficient, because monitoring the symptom only is enough to diagnose a sensor fault with no elaborate signal processing. Experiments were also performed to demonstrate the effectiveness of the proposed method in the detection and diagnosis of sensor faults.