Enhanced approach to cascade reconfiguration control design

Abstract

Following the concept of fault tolerant control systems, the paper is concerned with the problem of reconfiguration to retain fault tolerance in control of linear continuous-time systems with system dynamics faults. The main idea is to use a reference model output to be followed when a fault occurs, while the nominal control loop structure is kept untouched and the controllers with nominal parameters remains a part of the reconfigured control loop scheme. The full state control principle is applied for nominal control strategy and the static output control principle is proposed for the compensation control law. Exploiting the D-stability circle region precept, new conditions for control laws parameter design are introduced and proven, as well as stability of the cascade-like reconfiguration structure is analysed in the paper. To illustrate oncoming properties, the proposed feasible procedure is compared with that which was obtained using the bounded real lemma principle. The results, offering the sufficient and necessary design conditions, are illustrated with a numerical example to note the effectiveness of the proposed approach and its applicability.