Mathematical modelling and finite element analysis of the faults of aircraft wheel speed transducer

As the eye of aircraft brake system, the wheel speed transducer plays an important role in precise measurement of wheel speed and safe and efficient above-ground operation. However, engineering applications show that it is an assembly unit that is prone to suffer electrical/mechanical damages and provides inaccurate and even wrong signals. These signals may cause even more serious consequences, such as failures in the brake system, and poses grave threats to the safety of passengers and crews. An accurate mathematical model is a prerequisite to detect the faults of wheel speed transducers caused by those damages. In this paper, we establish mathematical models of the variable-reluctance type wheel speed transducer, both healthy ones and faulty ones (the fault of teeth loss and airgap eccentricity). These models are verified by comparing with the results obtained from finite element analysis, and then analysed the effect of these faults on the output signal of the transducer.