| In recent years,with the rapid development of the domestic automobile market,China has become a large country of automobile manufacturing and consumption.The National Development and Reform Commission's(NDRC)“the medium-term and long-term development plan of the automobile industry”,released in 2017,puts forward the requirements to break through the technical of key components of automobiles,and establish a safe and controllable industrial system.The pilot solenoid valve(PSV)is one of the key component of automobile automatic transmission(AT)system,and its response speed and control accuracy are the key factors that determine the performance of automobile shift,braking,lubrication and so on.High performance and efficiency performance measurement and control system is key equipment for solenoid valve research,development and production.In this paper,a series of measurement and control research work is implemented for the PSV used in new ten-speed AT,including valve modeling,a high-performance automatic measurement and control system with the international advanced level is jointly developed with enterprises.The main research work is as follows:1.Based on the working principle and performance parameters of the PSV,the requirements of the measurement and control system are clarified.Combined with advanced technologies,a detailed scheme design is made,and finally a measurement and control system of PSV is established.Taking the driving current and control pressure of PSV as examples,the measurement capability analysis of the system is carried out by measurement system analysis(MSA)method based on the statistical statistics and charts,and its repeat accuracy ability coefficient Cg,accuracy ability coefficient Cgk,data grading index,measurement data mean and standard deviation are all within allowable ranges,demonstrates that the designed system has high measurement accuracy,stability,repeatability and reproducibility accuracy.2.In view of the coupling with mechanical,hydraulic and electromagnetic characteristics in PSV,a modeling and analysis method based on the power bond is proposed.Based on the working principle of PSV,a power bond diagram is drawn and further the state equation of is derived.Without considering the pseudo-power flow such as fluid heating and energy dissipation in the actual operation of PSV,the pressure control characteristics under different input conditions are simulated by using 20-sim software,and the change relationship between pressure and current and temperature is basically consistent with experimental results of the measurement and control system,which proves the simplicity and effectiveness of the proposed modeling method for PSV based on power bond.3.In order to perfect the pilot solenoid valve model,the pseudo-power flow part of PSV is further modeled to achieve an effective complement to the valve model based on the power bond.Because the pseudo-power flow model of solenoid valve is complicated and difficult to model it accurately by traditional methods,an improved multi-layer neural network is proposed based on genetic algorithm to realize the rapid and accurate identification of pseudo-power flow.The joint simulation results of AMESim and MATLAB and the experimental results prove the effectiveness of the proposed identification method,the identification error of the pseudo-power flow of experimental results are all stable within ±5k Pa,which demonstrates the fast identification speed and high identification accuracy of this identification method.4.Since the PSV model has complex nonlinear characteristics,and there are internal parameter uncertainty and external interference in oil supply circuit,it brings great difficulties to the precise and stable control of supply pressure.In this paper,a fast terminal sliding mode controller is designed based on the principles of equivalent control and switching control.At the same time,in order to weaken the control signal vibration,a fuzzy controller is designed to adjust the switching control coefficient in real time.Using Matlab/Simulink for modeling and simulation,the simulation and experimental results all prove that the fuzzy-type fast terminal sliding mode controller designed in this paper has strong robust adaptability,and the chatter of the control signal can be greatly weakened.At the same time,the speed,accuracy and stability of the pressure control of PSV can be ensured.The related research in this paper not only provides a strong theoretical basis and technical support for research of the solenoid valve modeling and test method,but also has great significance for the design,development and control research of the solenoid valve.At the same time,it also has great reference value for the theoretical research and application of other fields of automation measurement and control,modeling and control technologies of complex nonlinear systems. |
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