Active fault tolerant control based on eigenstructure assignment applied to a 3‐DOF helicopter

In this paper an active fault tolerant control (AFTC) has been designed and applied to a 3‐DOF helicopter mathematical model. The main contribution corresponds to an AFTC design based on eigenstructure assignment aiming at reconfiguring the controller gain after actuator fault occurrences, modelled as additive faults. The reconfigured controller gain is computed ensuring the best approximation acquired for the nominal fault‐free closed‐loop system on its eigenstructure, giving rise to a faulty closed‐loop system with the same closed‐loop eigenvalues. Simulation results on the on‐line controller gain reconfiguration are shown considering simultaneous time‐varying faults and those with negative and positive slopes.