The invention relates to the technical field of state
estimation and fault detection, solves the technical problem that a traditional closed-loop fault diagnosis method cannot effectively decouple a
control signal and a residual
signal, and particularly relates to an uncertain random time-varying
system fault detection method considering
output feedback control. Comprising the following steps: carrying out theoretical modeling by adopting a linear
discrete system with model uncertainty to obtain a dynamic
mathematical model of the linear
discrete system; constructing a closed-loop
residual generator used for generating a residual
signal reflecting a
system state based on the dynamic
mathematical model; designing a fault
detection threshold value; and analyzing the fault detectability, and verifying that the linear
discrete system can be effectively identified and positioned when the fault occurs. According to the method, effective detection and diagnosis of the
system fault are realized under the condition of uncertainty of the norm bounded model, and minimization of the upper bound of the
estimation error variance of each step of
recursion calculation is ensured, so that a reliable and efficient fault diagnosis technical solution is provided.