Supervisory switching‐based prescribed performance control of unknown nonlinear systems against actuator failures

Abstract

Summary This article studies the fault‐tolerant control problem for unknown nonlinear strict‐feedback systems subject to actuator failures yet with dynamic redundancies. The prescribed performance control methodology is newly combined with a modification‐based supervisory switching strategy to solve the problem. To implement failure detection, the performance function is properly modified to synthesize a monitoring function to supervise the behavior of an error variable. Once a failure is detected, the current actuator is shut down and the backup actuator is switched in to execute the reconfigured control command. Compared with the existing results, (1) the postfailure and postswitching tracking performance is improved, other than uniform ultimate boundedness and (2) the dependence on extra robust control schemes (eg, adaptive or approximating structures) to deal with model uncertainties or the need to compute analytic derivatives of virtual control signals in the backstepping design is eliminated.

Adaptive output feedback fault‐tolerant control for nonlinear stochastic systems with output constraint

“…Since it is related to $$$ V(0) $$$ and $$$ \frac{4\overline{D}}{\Gamma} $$$, the initial values of system needs to be known, and the unknown parameters are in a known bounded compact set. The monitoring function in Reference 24 is $$$ \mid {z}_1\mid <{k}_1 $$$ $$$ \left({k}_1={p}_1+\sigma \right) $$$, only the constraint boundary $$$ {p}_1 $$$ and the given positive parameter $$$ \sigma $$$ are involved, which relaxed the strictly condition that the initial value of Lyapunov function is known. But, there is no standard condition that shows how to choose $$$ \sigma $$$, which will seriously affect the effectiveness of the proposed monitoring function.…”

“…As modern industrial processes become more and more complex and large‐scale, actual physical systems are prone to various failures 23,24 . Among all potential failure types, actuator failure is considered a serious threat because it directly affects system performance 25 .…”

“…As modern industrial processes become more and more complex and large-scale, actual physical systems are prone to various failures. 23,24 Among all potential failure types, actuator failure is considered a serious threat because it directly affects system performance. 25 The widely popular fault-tolerant control (FTC) schemes for actuator failure can be roughly divided into two categories: one is passive FTC, the other is active FTC.…”

Model reference adaptive control of piecewise affine systems with state tracking performance guarantees

“…Nevertheless, extra efforts are needed in our case for the design of auxiliary performance bound to bypass the barrier transgression problem. The fault‐tolerant approach 37 solves the barrier transgression problem by modifying the performance function when actuator failure occurs. Compared to this concept, our method imposes the auxiliary performance bound with certain dwell time constraints such that the modification of the original performance function is not necessary.…”

Extended prescribed performance control with input quantization for nonlinear systems

“…Transient and steady performance of closed-loop systems, resulted by various implemented controllers to plants, both theoretical research and practical application, is of major concern, and much efforts have been made to achieve performance improvement by advanced control schemes. [1][2][3][4] It is well-known that steady asymptotic tracking can be ensured via adaptive control in the absence of disturbances and uncertain dynamics, while there is no unified methodology which guarantees satisfactory transient performance. A model reference adaptive control is proposed to force the error, between outputs of system output and reference model, to be bounded by any positive constant (arbitrarily small) within specified time period, without requiring the information of relative degree and sign of high frequency gain, for a class of linear SISO system, 5 further, some other efforts concerning adaptive control to improve transient performance have been made.…”