Output-feedback fault tolerant control for linear time delay systems: Descriptor approach

In this paper we propose a new approach of fault estimation and Fault Tolerant Control (FTC) applied to Linear Time Delay (LTD) systems. To estimate the sensor faults we use the descriptor approach. This method consists in augmenting the state system by considering the faults as an auxiliary state. The used observer can estimate simultaneously both the state of LTD system and sensor faults. The observer gains are then determined according to Linear Matrix Inequalities (LMI) technique. For the step of FTC we construct an output-feedback gain to stabilize the LTD system not only in free-fault case, but also in the fault occurrence. A numerical example is proposed to demonstrate the efficiency of the given design for different form of sensor fault.