Model-based fault diagnosis of an actuator system driven by the brushless DC motor

A fault detection and isolation scheme for a brushless DC motor driving a mechanical actuation system is presented. First, a detailed mathematical model of the drive is derived. The residual generator is based on parity relations while the fault isolation part is implemented by means of the transferable belief model. The problem of distinguishing between faults with the same fault signatures is addressed. It is shown that additional improvements in terms of resolution can be achieved by employing parameter estimation. The proposed FDI scheme is tested on the actual drive under various faults. The achieved performance features the highest resolution, diagnostic stability and accuracy.