Integrated fault estimation and fault tolerant control for a class of uncertain Lipschitz systems with time-delays in finite frequency domain

Abstract This work describes an integrated fault estimation (FE) and fault tolerant control (FTC) strategy for a class of uncertain Lipschitz systems subject to time-delays in finite frequency domain. First, an FE filter is constructed by modeling the actuator faults and sensor faults as parameter changes. Second, an integral-type sliding mode FTC law based on the FE filter is developed, such that all states of the closed-loop system converge to the origin. By using the reconstructed Lipschitz property, the filter error system and the controlled system are rewritten as an augmented linear parameter varying (LPV) system. In addition, sufficient conditions for the augmented LPV system to have one full frequency and two finite frequency H ∞ index bounds are converted to linear matrix inequalities. Finally, two examples are delivered to demonstrate the validity and benefits of the proposed method.