The Researchs For Fault Diagnosis Algorithm And Simulation Based On Sliding Mode Observer

Aiming at the researches on current dynamic system's failure detection and diagnosis, on the basis of the sliding mode variable structure control algorithm, this thesis is focus on the common kind of non-line system's method for failure detection and diagnosis in industry area. The points are as follow:First, on the basis of the industry object modeling method, this thesis represented a method of sliding mode observer designing based on the variable sliding mode structure control algorithm. It realized the system state tracking on the specific equivalent principle of sliding mode variable structure. Comparing to any other parallel method, this one has less error and it works when with only one system state.Next, this article brought forward separately the diagnostic methodologies to the system component and sensor failure detection diagnosis on the grounds of sliding mode observer designing methods. Take the turnplate-simulating server for example, this methodology can easily ratiocinate the reasons for common abrupt failure, incipient failure and intermittent failure. Take the three-phase AC motor for example, it carries out the failure diagnosis to the sensor failure. The simulation test result proves the methodologies useful and practical.Then, this article illustrated a research on fault-tolerant control followed a fault restructuring. The fault-tolerance could be controlled when the controller's control-law were real-timely reconfigured. The control-laws of three kinds of common sliding mode variable structure controller were re-edited and tested on the stimulation. The result shows those controllers with a fault-tolerant function could be better controlled.Finally, taking the automobile electron throttle as an experiment subject, this article demonstrates how to design the observer and failure diagnosis system when unknown input disturbance exists. Through massive simulations, the above failure diagnosis algorithm, based on the sliding mode observer, was proved with a high stability against unknown input disturbance and have the ability to restructure the system component's failure without any false fault alarm. It has a great importance on the practical usage.