The Research And Implementation Of A Pressure Cylinder Control System Based On Fuzzy-PI

With the shortage of Marine resources becoming serious gradually, as well as therequirement of the exploration technology, the development and upgrading of the Marineequipment has been frequent and valued increasingly. In the process of the research anddevelopment of underwater equipment such as vehicle, underwater robots, underwateroperation tools and their components, the pressure test is an essential link. Because thedeep pressure simulation equipment on Laboratory can effectively shorten thedevelopment period of underwater equipment, and the pressure cylinder as a specialsimulate equipment, its design index is directly related to the performance and service lifeof the underwater equipment. Based on a certain new pressure cylinder pressure controlsystem, this paper put forward a kind of control strategy which composite fuzzy controland PI control, to meet the pressure control requirements of dynamic response rapidlyand high steady precision after the design and test.Based on the design index of the Pressure cylinder pressure control system, startingfrom the fluid mechanics formula related with pressure and volume change, aftercompared two kinds of pressure mode, which one is the change of volume,and the otherone is injection and drainage of water, considering the existing equipment,this paperchoose the latter method which injected the high pressure water to increase pressure ahdnatural drainage decompression,And completed the overall control architecture schemedesign,as well as the hydraulic control system. After the selection of important controlelements, the pressure control system of inertia transfer function and the analysis of thecharacteristics of hysteresis and oscillation of the guiding type pneumatic control valvewas achieved. Against the large inertia of the pressure control system and thecharacteristics of nonlinear and hysteresis of the regulating valve, the traditional PIDcontrol was difficult to achieve expected actual situation.Because it,the control strategycombining fuzzy control and PI control was proposed, in addition adopting the method ofdifferential ahead and integral separation to improve fuzzy control and PI controlseparately. Then based on the modeling and simulation calculation on the AMESIM simulation platform,the design of the structure of the fuzzy PI controller and optimizeand matching to the control parameters and fuzzy rules was completed. Finally, the fieldtest was taken on after transplanting control strategy to control system and programmingit for controling. The analysis of the result data geted from the field test proved that thefuzzy PI control strategy adopted in this paper can satisfy the requirement of systemdynamic and static control precision perfectly.The research work in this paper has a certain theoretical significance and referencevalue on the hydraulic control system which has the characteristic of the large inertia,time lag, time-varying and nonlinear.