| Electro-hydraulic shift control system is one of the core systems of automatic transmission,which has a direct effect on the precise control of the shift clutch's work pressure;therefore,the analysis and study of the system is an important part of automatic transmission's shift quality control and the precise control of shift clutch pressure of the system is a key aspect in the process of realizing shift control strategy.In this paper,by studying the electro-hydraulic proportional shift control system of automatic transmission used in a mining truck,using the electro-hydraulic proportional solenoid valve to replace the high-speed switching solenoid valve in the original system,through requirements analysis and comparative study to design the electro-hydraulic proportional shift control system and conduct system modeling and simulation;precise control of the shift clutch's work pressure in the 1-2 shift process of the system is realized and verify the electro-hydraulic proportional solenoid valve's superiority compared to the high-speed switching solenoid valve by making the shift shock indicators as the evaluation criteria,and shift quality of the electro-hydraulic shift control system is improved.Firstly,a hydraulic control apparatus of automatic transmission is analyzed and the composition and function of the various subsystems are defined,which include the transfer logic and control theory of ECU/TCU electronic control signals in electro-hydraulic control system,structure and control theory of the solenoid valve,structure and regulation principle of pressure regulator valve,composition and response characteristics shifting clutch / brake actuator;Secondly,theoretical analysis and modeling of the high-speed switching solenoid valve and electro-hydraulic proportional solenoid valve are conducted,parameter identification modeling research on electro-hydraulic proportional solenoid valve based on AMESim platform is completed;Study on requirements analysis of the clutch pressure control system,simulation model of the electro-hydraulic shift control system is established respectively based on high-speed switching solenoid valve and electro-hydraulic proportional solenoid valve;taking 1-2 gear shift process as an example,a comparison of the shift clutch working pressure response characteristics based on two solenoid valves during shift process is conducted,and verified electro-hydraulic shift system based on the proportional solenoid valve advantages in the clutch oil pressure control from the perspective of simulation;while adding PID algorithm to the electro-hydraulic shift system based on proportional solenoid valve to realize response tuning of the oil pressure control,in order to enhance the accuracy of the clutch hydraulic control system;Finally,based on AMESim-MATLAB/Simulink co-simulation platform,add the AMESim hydraulic system to the MATLAB/Simulink vehicle dynamics system to conduct co-simulation research and study vehicle shift quality;by making the shift shock indicators as the evaluation criteria,electro-hydraulic shift based on electro-hydraulic proportional solenoid is better than the electro-hydraulic shift based on high-speed switching solenoid valve,which verifies the improving of the shift quality by electro-hydraulic proportional solenoid valve. |
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