| In recent years,with the rapid expansion of the automobile consumer market,consumers have put forward more and more stringent requirements for the comfort and economy of automobiles.Dual Clutch Transmisson(DCT)has gradually become the focus of automatic transmission due to its good power output characteristics and high mechanical efficiency.The hydraulic control system is one of the core modules of the wet DCT,which has the characteristics of strong nonlinearity and time-varying system parameters.Its system performance has an important influence on the start and shift control of DCT.Relying on a school-enterprise cooperation project,this paper completes the research on the wet dualclutch hydraulic control system,analyzes modeling and test verification of the hydraulic system,and analyzes the influence of system parameters on the response characteristics;on this basis,complete with the vehicle model Analysis of its impact on the start-up process.The main research contents are as follows:(1)Firstly,the composition structure of the wet dual-clutch hydraulic control system is introduced,and the working principle of the main oil circuit pressure control system and the clutch pressure control system are analyzed;the electromagnetic,hydraulic and mechanical parts of each subsystem are analyzed and considered The influence of hydraulic components such as accumulators and piston chambers is considered,and the mathematical models of the various subsystem components of the hydraulic system are established.To lay a theoretical foundation for the simulation analysis of the hydraulic control system.(2)Based on the theoretical analysis of the dual-clutch hydraulic control system,using AMESim simulation software,a simulation model of the various subsystems and hydraulic components of the wet clutch hydraulic control system was built;relying on the hydraulic valve body inspection test bench project,the hydraulic system model was carried out It has been verified by experiment and verified the accuracy of the built model.On the basis of the simulation model,the design parameters and structural parameters of the hydraulic system are parameterized and analyzed,and their influence on the dynamic characteristics of the step response of the system pressure is studied.(3)In order to ascertain the impact of the hydraulic control system on the starting process,a vehicle model including the engine,wet clutch,gearbox,and driving resistance model was first built;the wet clutch is used as the hydraulic control system to connect with the vehicle model.For the key nodes,the torque transmission characteristics and the coupling process are analyzed in detail,and the torque transmission model of the wet clutch is established.The clutch hydraulic control system and the vehicle model are coupled into a DCT vehicle starting model to provide a simulation platform for subsequent analysis.(4)Established the vehicle dynamics model during the starting process,and analyzed the starting quality evaluation index;on this basis,analyzed the clutch control strategy of the wet DCT starting process,and analyzed the control strategy of the clutch engagement pressure during the starting process.And the engine target speed control strategy;based on the DCT starting model,the vehicle starting process is simulated and analyzed,considering the response characteristics of the clutch pressure control system,the influence of the key parameters of the hydraulic system on the impact degree and sliding friction work of the starting process is analyzed. |
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