Research On Multi-cylinder Synchronization Control Strategy For Ring Gate Electro-hydraulic System

In this dissertation, multi-cylinder synchronization control strategy for ring gateelectro-hydraulic system is the study subject. Some factors cause bad effects onmulti-cylinder synchronization, such as nonlinear parameters, coupling load andexternal disturbance. Basing on the mathematical model of the ring gatemulti-cylinder synchronization control system, a model reference fuzzy adaptivecontrol strategy is presented. To research the static and dynamic performances of ringgate electro-hydraulic system, Tianjin University and ZHEFU Corporation jointlydevelop the ring gate prototype testing device. Through experimentation, the resultsprove validity of the proposed strategy. Following contents are included in this thesis:(1) The workings of ring gate electro-hydraulic system under differentconditions are analyzed separately based on introducing ring gate electro-hydraulicsystem. From the perspective of system control, the ring gate electro-hydraulicsystem is divided into two parts—speed control and multi-cylinder synchronizationcontrol. Owing to the limitation of the mathematical model of speed control, itsphysical model is established in AMESim software in this thesis.(2) A nonlinear mathematical model of ring gate multi-cylinder synchronizationcontrol system is established based on the mathematical model of the high speedon-off valve controlled cylinder mechanism. And it turned out that ring gatemulti-cylinder synchronization control system is a kind of multi-input andmulti-output nonlinear time-varying system. The effects of various parameters on themulti-cylinder synchronization control system are also analyzed.(3) A model reference fuzzy adaptive control strategy is proposed, whenconsidering the characteristics of the system, both adaptive control method and fuzzycontrol method. With the AMESim/Simulink co-simulation, the comparison betweenmodel reference fuzzy adaptive control strategy and PID control strategy is conducted.The results show that the proposed control strategy is more adaptable and morerobust.(4) Hardware system and software system of ring gate prototype testing deviceare built. The proposed control strategy is verified on the device. The test data curveshows that the maximum displacement deviation in ring gate opening and closing canbe kept in2mm and the ring gate speed is satisfactory. The analysis indicates that the model reference fuzzy adaptive control strategy is effective.