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With the continuous development of the automotive automatic transmission technology, countries in research and development of the nationally appropriate vehicle automatic transmission. The dual-clutch automatic transmission (DCT) is in the manual transmission on the basis of the development of a new type of automatic transmission, not only to maintain the AMT transmission efficiency, the advantages of cheap, but also to overcome the shortcomings of the AMT shift when the power interruption, like AT and CVT as power shift, so by the manual transmission-based national attention. Dual wet clutch as the main components of the DCT, its precise control is one of the key technologies developed by DCT. This article looks at the study of dual wet clutch engagement law, aimed at finding the best parameters of a set of the clutch positive pressure linear change, the clutch shift performance indicators to achieve optimal. First, a brief introduction the DCT and wet dual-clutch the composition, structure type and working principle, and then wet dual-clutch simplified model based on its process of shifting and clutch release engagement conditions detailed kinetic analysis. Shift process is divided into five stages, given the various stages of system dynamics described differential equations (groups), and wet dual-clutch shifting process Simulink simulation model is established on this basis. For second gear to a file, for example, the use of Simulink simulation model established wet dual-clutch shift was simulated, and the simulation results, qualitative analysis of the slope of the positive pressure changes, the beginning and end pressure and clutch with the right timing wet dual-clutch shift performance indicators, draw some useful conclusions. Upshift, positive pressure the greater the change in slope, the shorter the time shift, the smaller the resulting friction work, the greater the degree of vehicle impact; smaller the beginning and end pressure, the shorter the time shift, the smaller the resulting friction work , the smaller vehicle impact; two clutches Buck-Boost simultaneously started, the shift time is shorter; combination of the clutch positive pressure rise lag time is the longer, the smaller the friction work generated, the smaller the degree of vehicle impact. On the basis of qualitative analysis, based on multi-objective optimization theory, given the use of a weighted combination of law to seek the optimal parameters of the linear shift, and programming the process, optimum shift parameters. Through comparative analysis, to verify that the shift of the parameters corresponding to the three shift performance indicators are better, so that this parameter is from the perspective of engineering applications, the optimum parameters of the linear shift, to prove this The optimization method is feasible.
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