Robust fault tolerant control of a DC motor in the presence of actuator faults

A robust methodology for the Fault Tolerant Control (FTC) of a permanent magnet DC motor in the presence of different types of actuator faults is developed and tested in this paper. The Fault Detection and Isolation (FDI) is achieved by employing the Observer based residual scheme. In order to make the generated residuals insensitive to disturbances and uncertainties, the method of Eigenstructure Assignment (EA) is also incorporated in the FDI scheme. The Sequential Probability Ratio Test (SPRT) is employed for the efficient statistical testing of the residuals. Subsequently the Multiple Models Switching and Tuning (MMST) technique based on Linear Quadratic Gaussian (LQG) regulator is designed and used as the reconfigurable controller. The robustness and efficiency of the developed FTC system is illustrated through simulations on a permanent magnet DC motor model.