Study Of Hydraulic Loading System Based On Differential Pressure Feedback And System Decoupling

With the development of space enterprise,the maneuverability and control precision of the aircraft are getting higher,and thus,it also puts forward higher requirements for the performance of load simulators.Since the Electro-hydraulic load simulator(EHLS)has the advantages of high power,fast response and high precision,it has become a hot research area.At the same time,using control theory and methods to further improve the performance of EHLS has been a popular research aspect and development trend.Coupling relationship is the main factor that affects the force loading precision of the load simulation system.It is very important to deeply study the mechanism and the suppression method of the coupling relationship.The main work of this thesis is as follows.Firstly,the research background and significance of the load simulation system,and the review status of the hydraulic loading system and its control methods domestically and overseas are introduced.The existing research results and shortcomings of decoupling control are also analyzed.On the basis of establishing the mathematical model of the differential pressure feedback mechanism and the position control load mechanism,through analyzing the generation mechanism of the coupling relationship,the integrated transfer function model and the state space model of the hydraulic loading system and coupling characteristics are established,and then the mechanism and characteristics of excess differential pressure are simulated and analyzed.Furthermore,the theory of decoupling control algorithm is analyzed,and the condition of decoupling control is given.In terms of the state space model of excess differential pressure,an integral dynamic decoupling control algorithm for suppressing excess differential pressure is designed,and the conversion matrix of the decoupling canonical form is given.The practical value is brought into the decoupling controller,and the validity of the decoupling controller is verified by simulation.Finally,based on the above analysis and the practical parameters of the hydraulic loading system,the overall scheme of the hydraulic loading system test platform is proposed.The mechanical structure is designed and software and hardware system of the hydraulic loading are accomplished.The related scheme is realized on the physical system.Experiments are conducted to verify the feasibility and effectiveness of proposed decoupling controller for suppressing the excess differential pressure in this scheme.