Abstract: Aiming at the problems of nonlinear pressure control, large timelag and variable parameters, a closed loop pressure control system is designed based on selfadaption fuzzy PID technology. By online adjusting of the proportional coefficient Kp,the integral coefficient Ki and the differential coefficient Kd of the controller, high precision control of the pressure is realized. Based on the test data, a secondorder lag inertia model is established by curve fitting and simulation. The simulation verifies the validity of the model. The conclusion shows that this control effect is better than the conventional PID control, and can effectively improve the dynamic performance and steadystate accuracy of the system. It can be widely used in the automatic control system of the launch site where PLC control is a core method.

Key words: font-family: 宋体, mso-bidi-font-family: 宋体, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">injection gas supplyfont-family: 宋体, mso-bidi-font-family: 宋体, mso-ansi-language: EN-US, mso-fareast-language: ZH-CN, mso-bidi-language: AR-SA">, fuzzy control, PID, data fitting, system modeling, simulation