An integrated design method for active fault diagnosis and control

Abstract

SummaryThe injection of an auxiliary input signal for active fault diagnosis may cause the change of system control performance in closed‐loop operation. This paper presents a novel integrated design method for active fault diagnosis and tracking control in order to facilitate the detection of incipient faults, meanwhile ensuring the normal operation of the closed‐loop system. First, a zonotopic filter is generated based on radius minimization method to estimate the uncertain bound set of systems states. Then, an auxiliary input signal is designed to separate the reachable sets of the system in healthy and faulty operation situations. Generally, the auxiliary input signal is required to be designed minimizing the system closed‐loop performance degradation. In this paper, a tracking controller is designed altogether with the auxiliary input signal to make the system output track a given reference. An optimal index is proposed to minimize simultaneously the energy of the auxiliary input signal and the output tracking error. Next, a fault detection logic is provided based on checking whether the closed‐loop system state belongs to healthy zonotope. Finally, the feasibility and advantages of this work are verified by means of a numerical example.