| The pressure servo valve has the advantage of being able to output the control pressure linearly,and is widely used in the force application system with high control accuracy requirements.The research of pressure servo valve involves various key fields such as national defense,industry and civil use,so it has always been a research hotspot.With the improvement of China ’s industrial technology,the demand for pressure servo valves and their performance requirements are getting higher and higher.However,the research on pressure servo valves in China started late and relatively few.For a long time,the pressure servo valves produced in China have a certain gap in performance with foreign countries.Therefore,it is of great theoretical and practical significance to carry out the research and analysis of domestic pressure servo valves.In this paper,a series of simulation and experimental analysis are carried out for a new type of domestic jet pipe pressure servo valve to study its dynamic characteristics,the influencing factors of dynamic characteristics,the influence law of each parameter and the stability boundary of key parameters.The main research contents of this paper are as follows :(1)Mathematical modeling and simulation analysis of pressure servo valve control cylinder system.The special structure and working principle of the pressure servo valve are introduced.The mathematical model of the pressure servo valve control cylinder system is established,including the mathematical model of the pressure servo valve and the load characteristic model.The MATLAB / Simulink simulation model of the pressure servo valve control cylinder system is built,and the dynamic characteristics of the system are analyzed under different working conditions.The transfer function of the pressure servo valve control cylinder system is derived,and the natural frequency and damping ratio of the system are calculated.(2)Analysis of key factors affecting the dynamic characteristics of pressure servo valve control cylinder system.The distributed parameter model of hydraulic pipeline is established,and the transfer function from the outlet flow of pressure servo valve to the outlet pressure after considering the pipeline is obtained and the Bode diagram is drawn.At the same time,the MATLAB / Simulink simulation model of the system after considering the pipeline is built.According to the Bode diagram and simulation analysis results,the influence of various parameters of hydraulic pipeline on the dynamic characteristics of the system is analyzed.The influence of different pulsation frequency and pulsation amplitude of hydraulic oil supply / return pressure on the dynamic characteristics of the system is analyzed.The mathematical model of the system considering hysteresis nonlinearity and friction nonlinearity is established,and the influence of the two on the dynamic characteristics of the system is analyzed.(3)The influence law of pressure servo valve control cylinder system parameters and the stability boundary analysis of key parameters.The state space model of the pressure servo valve control cylinder system is established,and the second-order trajectory sensitivity theory is derived.The second-order trajectory sensitivity of 34 parameters in the system is obtained under the step signal condition.According to the results of second-order trajectory sensitivity analysis,the influence law and degree of 34 parameters on the system are summarized,and the key parameter group with the greatest influence on the system is obtained.The stability boundary discrimination method is given from the perspectives of time domain and frequency domain,and the stability boundary of key parameters is analyzed.(4)The dynamic characteristics test bench of pressure servo valve controlled cylinder system is built for experimental verification.The dynamic characteristics of the system are tested under various working conditions to verify the accuracy of the mathematical model and simulation analysis results.The accuracy of the theoretical analysis results of the influence of hydraulic pipeline on the system is verified by experiments.Experiments verify the accuracy of the second-order sensitivity analysis results. |
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