The Design Of Variable Mach Wind Tunnel Control System And Application Of Adaptive Fuzzy Control Algorithm

Variable mach wind tunnel is used to the research of engine under varying mach conditions, including flow mechanism and aerodynamic performance inside the engine. It is an important means of testing the performance of hypersonic vehicle in the aerospace field. The control system of heater supply is the important guarantee of providing airflow conditions in variable mach for the blowing test of the wind tunnel, while the particularly importance is the flow and pressure control to each component gas. Traditional PID control algorithm is used in the original wind tunnel control system in institute of mechanics, but it is difficult to achieve good control effect for the complex control system. For this situation, the following research are conducted in this paper:The hardware and software are designed base on the status of low level in automation to the original wind tunnel control system. The structure of similar SCADA control system is designed, including control program of PLC and monitor screen of WinCC. This design make information technology and control technology establish seamless connection and achieve management and control integrated.The double-loop cascade loops of flow and pressure are designed according to the principle of achieving variable mach and pipeline construction of heater supply system. The mathematical model of the system is established by test modeling methods, including the using of recursive least-square identification and experimental data.Because of the complex structure of the heater supply system and the impact of many factors, with variability, nonlinear, time delay, difficulty of establishing a precise mathematical model and other characteristics parameter. An parametric adaptive fuzzy control algorithm is designed for the control system of heater supply based on these characteristics. This algorithm improve the traceability and stability of unsteady process control. The Matlab simulation results verify that the parametric adaptive fuzzy controller is better than the traditional PID controller for the control effect, and can meet the control requirements.