Fault detection in electromagnetic suspension systems with state estimation methods

A procedure is presented for the design of a fault diagnosis and isolation (FDI) subsystem for electromagnetic suspension systems. This subsystem is based on the Luenberger observer and logical analysis. Using the position sensor output, the observer estimates the state variables. One critical feedback variable is the vertical acceleration of the suspended magnet. The fault of the accelerometer is detected by comparing its output with the estimated state variable. At the same time, a redundant accelerometer takes over to sustain stability. Experimental results illustrate the feasibility of this method