Research ArticleFault detection for discrete-time switched systems with sensor stuck faults and servo inputs

•We investigate the fault detection problem for switched systems with servo inputs and sensor stuck faults.•Under the proposed switching strategy, the finite-frequency l2-gain and Hi index are guaranteed.•The sensitivity between the residuals and servo inputs in fault-free and faulty cases are considered, which guarantees small sensor stuck faults including outage faults can be detected

This paper addresses the fault detection problem of switched systems with servo inputs and sensor stuck faults. The attention is focused on designing a switching law and its associated fault detection filters (FDFs). The proposed switching law uses only the current states of FDFs, which guarantees the residuals are sensitive to the servo inputs with known frequency ranges in faulty cases and robust against them in fault-free case. Thus, the arbitrarily small sensor stuck faults, including outage faults can be detected in finite-frequency domain. The levels of sensitivity and robustness are measured in terms of the finite-frequency H− index and l2-gain. Finally, the switching law and FDFs are obtained by the solution of a convex optimization problem.