The Study Of Fault Tolerant Control Method

The reliability is the key to working smoothly of the system. However, in automated processes, the system may be broken so as to reach the undesired reactions. Therefore, the study of fault-tolerant control has become one of the hot areas. The reasons for working unwell of the system are manifold, but the following are studying in this paper. One is the broken components, mainly the failure of actuator and sensor; and another is time delay, which always effects on the stability and performance of the system. So it is of significant theoretical and practical engineering meaning to study on the fault-tolerant control and time-delay system.In this paper, the fault-tolerant control is investigated by linear system and linear uncertain time-delay system, mainly for the following aspects of work with the Lyapunov stability theory, memoryless state feedback, delay memory state feedback and linear matrix inequality: The main research works in this paper can be summarized as follows.(1) The fault-tolerant control is studied for linear system. The fault-tolerant control problem when the actuator and sensor are failure respectively or simultaneous. If some actuators and sensors can work, we could have the sufficient condition of system stability with Lyapunov stability theory; make the conditions of existence of the controller into a set of linear matrix inequality feasibility problem. In the premise of system stability, discuss guaranteed cost control and H∞control for linear system, when adding actuators or sensors, we can found when fewness actuators are normal, add the normal actuators and sensors, which makes performance index no more than the less one, the gain of the linear system will be samaller and the performance will be better.(2) The research on the fault-tolerant control is investigated for the linear uncertain time-delay system. For the state delay system, the uncertain of the state and input are norm bounded, apply memoryless state feedback to linear system, make a new Lyapunov function with Lyapunov stability theory, study on the sufficient condition of system stability when the failure of actuators and sensors, have the method of design controller, make the conditions of existence of the controller into a set of linear matrix inequality feasibility problem. This method could lower the conservative and upper bound of time delay of linear system. In the context of system stability, make some elements of K is unchanged; add the normal actuator and sensor, make the performance of system is no less than the system of less actuators and sensors.(3) Study on the fault-tolerant control of the linear uncertain time-delay system with delay memory state feedback, for the state delay system, the uncertain of the state and input are norm bounded, apply memoryless state feedback to linear system, struct a new Lyapunov function with Lyapunov stability theory, study the sufficient condition of system stability when the failure of actuators and sensors, have the method of design a fault controller, make the conditions of existence of the controller into a set of linear matrix inequality feasibility problem. This method could lower the conservative of system, and make the less upper bound of time delay. In the context of system stability, make the element of K is unchanged, add the normal actuator and sensor, make the performance of system is no less than the system of less actuators and sensors.