Fault-tolerant Control Of Electrohydraulic Servo System

The modern engineering technique system is coming towards the direction that is large-scale and complicated. Once this type of system takes accident it may result in huge loss of the personnel and property. Therefore, it is actually very important to keep this modern and complicated system safe and reliable. Although the fluid power industry is a newly emerging field, the industry application in hydraulic and pneumatic equipments has made a rapid progress since the II World War has been over. Particularly it is well worth to say that, in recent years the extensive application in intelligence system which is produced by the extensive application in electro hydraulic ratio valve and servo-valve and the combination in microprocessors and fluid power components, make fluid power system and control technique permeate in almost all sorts of trades of society. At the same time, the reliable of this complicated large-scale hydraulic equipment, especially the electro hydraulic servo control system acting as core seems very important.Based on the thought of reliable research, this paper makes an analysis on electro hydraulic servo system fault and a research in its fault tolerant control. According to fault characteristic of the electro hydraulic servo system, this paper has proposed a fault tolerant project that uses the fuzzy neural network as an identifier on-line. This paper mainly does the following three work.(1) This paper take analysis on the fault characteristic of electro hydraulic servo system and based on this analysis this paper set up a fuzzy neural network identifier and make fuzzy experience rule better using back propagation algorithm.(2) Use a great deal of sample to train the fuzzy neural network off-line.(3) Set up a fault tolerant control system with fuzzy neural network and have a simulink simulation to this fault tolerant control system.The simulation presents that the identifier of fuzzy neural network can satisfy the request on high respond and high accuracy in electro hydraulic servo system.In recent years, the fault tolerant research in dynamic system has made a great development, but the fault tolerant research in electro-hydraulic servo- system is not found in domestic. The purpose of this paper is to apply fault tolerant control theories to the design of electro hydraulic servo system in order to raise its reliability. In large continuous production line which core control is electro hydraulic servo control system fault tolerant control can avoid the equipment damage which is done by small controlling trouble and there will be no loss which is done by shutting down to repair because of abrupt accident. Therefore, the fault tolerant control research in electro-hydraulic servo-system has more important realistic meaning.