Research On Control System Of Deep-sea Pressure Simulator

Deep sea resources exploration is one of the key points in the development of marine technology in China.It is inseparable from submersible and marine measurement equipment.Marine pressure is one of the key factors that affect the performance of detection equipment.Therefore,a high-precision deep-sea pressure simulator is indispensable.First,the overall design of the pressure simulator is carried out.A new high precision pressure simulation device based on the combination of double piston hydraulic cylinder is designed to solve the problem that the traditional piston pressure simulation device can not simultaneously have both high pressure response and high precision.Based on the control performance and pressure precision requirements of the pressure simulation device,the pressure simulation control system is designed,including the design of electrical equipment and pressure vessel and the selection of parameters,and the hardware and software development environment of the system is selected.Secondly,according to the principle of liquid compressibility,the transfer function of pressure simulation system is derived.Based on Matlab simulation,the pressure simulation accuracy of single piston hydraulic cylinder pressure and double piston hydraulic cylinder is compared.The results show that under the 0.2Mpa step response,the pressure simulation system of the double piston hydraulic cylinder reduces the steady-state error of the single cylinder than the single hydraulic cylinder by 0.0012 Mpa.In view of the nonlinear and time-varying characteristics of the system,the PID and fuzzy PID control methods are compared.The simulation results show that the fuzzy PID control reduces the overshoot and improves the steady state precision.Then the test platform of pressure simulator is built by industrial control computer.The upper computer of the pressure simulation device is compiled by using the MFC interface framework,and the pressure data acquisition,display and storage are realized.Through multimedia timer,pressure control cycle is achieved.Aiming at the problem that the pressure signal is easily disturbed,a filter algorithm combining mean filter and Calman filter is designed to reduce the noise of pressure.Finally,the static pressure,trapezoidal pressure and sinusoidal pressure simulation experiments were carried out on the pressure simulator.The results show that under the static pressure response of 1Mpa,the maximum error of the pressure simulation system of double piston hydraulic cylinder is 0.005 Mpa.The pressure simulation system has good dynamic pressure simulation performance.