Research On Air Intake Pressure Control Method Of Aerial Platform Based On Real-time Simulation Platform

The intake pressure control system is the core control system of the high altitude platform.It is the key to guarantee the effectiveness and reliability of the high-altitude simulation test.There exist problems of numerous disturbances in the control system when the aero-engine conducts transition state experiments.This thesis proposed an inlet pressure control method based on the real-time simulation platform of the high-altitude stage to solve these situations.The method is mainly based on the improved super-twisting control algorithm,which realizes the fast tracking and stable control of the inlet pressure in the transition state.And the strategy is verified by the simulation on the real-time simulation platform of the high-altitude platform.This thesis focuses on the following aspects of the research.(1)Construction of real-time simulation platform.In view of the high requirements of the aero-engine transient state experiment on the system,the simulation process of the real-time simulation platform is analyzed by studying the real-time simulation systems such as dSPACE and RT-LAB.And a real-time simulation platform based on Matlab/XPC is designed and built,which lays a foundation for further research on the intake pressure control algorithm.(2)Model analysis of air inlet control system of altitude platform.The existing intake pressure control system model of high altitude platform is analyzed,and the mechanism model of key test equipment such as valve,cavity and hydraulic system is theoretically derived.The intake pressure control process of high altitude platform is mastered,and the component level model of intake pressure system of high altitude platform is established.These lays the model foundation for the research of intake pressure control method.(3)Research on the intake pressure control method of high altitude platform.An improvedSuper-twisting control method is proposed for the problems of slow response and large overshoot of the transition state system of the aerial table.By redesigning the sliding surface of the slide control,the method achieves the balance between the rapidity of the control system and the overshoot amount.First,the PD control strategy is introduced into the design of the sliding mode surface for super-twisting control,which accelerating the response speed,suppressing the overshoot amount and improving the dynamic quality of the system.Second,to address the jitter problem brought by the sliding mode control,the sign function in control is replaced by the hyperbolic inverse tangent function.And the discontinuous term in the sliding mode control is made continuous,which weakens the jitter problem of the traditional sliding mode control.(4)Real-time simulation verification of intake pressure control of a high altitude table based on super-twisting control.The proposed improved super-twisting control method is verified in the engine transition state experiments under the constructed Matlab/XPC based simulation environment.The experimental results show that textual methods can achieve fast pressure tracking and stable control of the engine transition state,and can resist the shock disturbance of rapid changes in engine flow.