Advances in fault diagnosis and fault tolerant control motivated by large flexible space structure.

摘要

In this thesis, two problems are studied. The first problem is to find a technique to generate a particular type of failure information in real time for large flexible space structures (LFSSs). This problem is solved by using structured residuals. The failure information is then incorporated into an existing fault tolerant control scheme. The second problem is a "spin-off" from the first. Although the H-infinity sliding mode observer (SMO) cannot be applied to the colocated LFSS , its ability to do robust state and fault estimation of the SMO makes it suitable to be used in an integrated fault tolerant control (IFTC) scheme. We propose to combine the H-infinity SMO with a linear fault accommodation controller. Our IFTC scheme is closed loop stable, suppresses the effects of faults and enjoys enhanced robustness to disturbances. The effectiveness of the IFTC is illustrated through the control of a permanent magnet synchronous motor under actuator fault.