Self-triggered fault estimation and fault tolerant control for networked control systems

H∞ Guaranteed Cost Fault‐Tolerant Control of Double‐Fault Networked Control Systems: Piecewise Delay Method

“…The networked control systems in faulty case can be modelled as system (21) with the effects of time-varying delay ( ) whose upper bound and lower bound are described in (12). Unlike the previous models, [17,21,27,35], this model is related to both sensor faults and actuator faults, the faults are time-varying, which are reflected by the time-varying parameters ( − ( )) and Γ( ). From 17, we undoubtedly know the time-varying parameter ( − ( )) satisfies = 2 ≤ , while the parameter Γ( ) satisfies Γ Γ = Γ 2 ≤ .…”

“…From the descriptions of faults matrices, we undoubtedly know if = 1/ 0 − 1 ( = 1, 2 ⋅ ⋅ ⋅ , ), we can obtain = 1 and 0 ( + ( − ( ))) = , and then model (21) is an actuator fault model. Similarly, if = ( − 0 )/ 0 ( = 1, 2 ⋅ ⋅ ⋅ , ), we can obtain = 1 and Θ 0 ( + Γ( )) = , and then model (21) represents a sensor fault model. Therefore, model (21) of a double-fault NCS contains cases of singlefaults, and the single-faults are a special form of double-faults.…”

“…Definition . For model (21) and its cost function (22), if there exists a control gain matrix satisfying the conditions…”

“…To achieve stability requirements concerning sensor faults or actuator faults, fault-tolerant control has been investigated in many works [15][16][17][18][19][20][21][22][23][24][25][26]. Based on the Lyapunov stability theorem, a methodology for the design of faulttolerant control systems for chemical plants with distributed interconnected processing units was presented by N. H. El-Farra and A. P. D. Gani [15].…”

Finite‐horizon fault estimation under imperfect measurements and stochastic communication protocol: Dealing with finite‐time boundedness

“…It is generally known that the fault occurrence can be ascertained via the fault detection techniques that have attracted considerable research attention, whereas the detailed information (eg, quantity, size, and type) of the occurred faults can be acquired through the fault estimation procedure, which serves as a prerequisite for the subsequent task of fault‐tolerant control . With the ever‐growing demands toward security, reliability, economical efficiency, and working life of NCSs, the fault detection and estimation problems have been widely analyzed so far, and numerous research outcomes have been recorded in the recent literature (see, eg, other works and the references therein). To be specific, the fault detection/identification issue for nonlinear process has been investigated in the work of Samuel and Cao by means of the kernel principal component analysis‐kernel density estimation technique.…”