Fault Detection And Control For Linear Systems With Sliding-mode Observer

As industrial process inclines to be larger and more complicated, the system requires much higher reliability and safety, so fault detection and fault tolerant control have been the subject of intensive research, and the model-based fault detection and fault tolerant control approach has been accepted as a widely used effective approach in the literature. Recently, H∞techniques have been introduced in model-based fault detection and fault tolerant approach to deal with the disturbance robustness and fault sensitivity problems. The development of the dynamic system’s fault tolerant control is due to the evolution of fault detection based on analytic redundancy. The state observer not only provides the practical possibility of redundancy and state feedback, but also has been applied in many aspects of the control project. The biggest advantage of using sliding observation is, when in the process of sliding, the observation is sensitive to the matching summation input. Sliding mode variable structure is essentially a special kind of nonlinear control. So sliding-mode observer has very broad prospects and fault-tolerant control and fault detection based on the sliding-mode observer will become one of the hot topics which domestic and overseas scholars study.This paper first briefly introduces the research purpose and significance of fault-tolerant control, fault detection; the concept and found status of sliding-mode observer, and then analyzes the main problems in existing papers. Aiming at these problems, this paper adopted the integral type design of control test system, in which the controller and observation are designed simultaneously. At the end, overview the system model, the structure of observer and controller and the based knowledge needed.This paper aims at working out the fault occurring time of the disturbed system when there is a fault, and designing a sliding-mode observer and controller to make the system meet given performance. By choosing a new factor and adopting matrix replacement technology and related lemma, a set of LMIs can solve the problem of four limited low-frequency faults and high frequency disturbances. Also, this paper gives the stability condition according to Lyapunov stability theory when controller and observer effect simultaneously. By using linear matrix inequality toolbox, we solve controller and observer parameters, and design appropriate Simulink module. Numerical examples are given according to each fault condition and show the effectiveness of the conclusion.