Actuator fault estimation with disturbance decoupling

The described work is on actuator fault estimation with disturbance decoupl ing that makes it possible to diagnose actuator faults. To achieve reliable fault estimation, unknown input decoupling is combined with an observer, l eading to a diagnostic observer. As a result, the observation error equatio n for the diagnostic observer does not depend on the effect of unknown inpu ts and is used to construct a diagnostic algorithm that provides an estimat e of the gains of actuators; this can be obtained directly via the augmente d error technique. This approach is compared with the design previously rep orted in the simulation. The simulation results indicate that the proposed algorithm is more realistic, in the Sense that better decoupling properties can be assured without knowledge about unknown inputs, and it is potential ly useful in the development of a fault-tolerant control system.