Research On Start And Shift Character Of Dual Clutch Transmission

With the development of automobile automatic transmission, various of automatic transmissions suited to own national condition are researching and developing. Dual Clutch Transmission (DCT)is a new type of automatic transmission based on manual gearbox. It retains the advantages of the Automated Mechanical Transmission, for example, simple structure and high efficiency, at the same time it could overcome the shortcomings of the AMT shift at the power interruption and change the ratio under the power on, so it reduces the shift time and improves the shift quality. The DCT incorporates the merits of MT, AMT, and AT, so many manual gearbox to the countries attach great importance.This paper mainly studies on the following aspects based on the six-speed wet Dual Clutch Transmission.It introduces the production and the application prospect of DCT.Moreover, it analyzes the DCT on the structural features, working principle, the composition and function. Dual Clutch Transmission has two input shafts and two clutches, by right controlling the two clutches. DCT needn't cut off the power when shifting, thus it can be achieved the purpose of power starting and shifting.At last,it could effectively improve the quality of starting and shifting.It contrasts the structrue of two types of wet dual clutch, and the characteristic of wet and dry clutch. It builds the clutch engagement model.The engine is the source of the car power, so it is the base of the powertrain simulation. And the engine model is built for the vehicle simulation system. Based on analyzing the starting and shifting process, it decides the work patterns of the DCT according to the different clutch friction modes.The Dual Clutch Transmission dynamic model for simulation is built.According to research,it established the eight-freedom vehicle model and analyzed the two important criteria of the clutch engagement process.The clutch must be start rapid and adapt to the change of the load and gradient, reduce the wear of the clutch. So it is a difficult problem.The paper is based on the establishment of the dual clutch transmission start dynamic model.Through analyzing the engagement rule of the clutch, the starting control strategy is put forward that 1st and 2nd gear are both applied in the process of vehicle startup simultaneously.And it could fuzzy control the two clutches engaging intensity and the startup gear according to strategy of the different startup conditions and driver's intention. Using Matlab/ Simulink software, it sets up simulation model and analyzes the starting process of the DCT, The simulation results indicate that the adopted starting fuzzy control strategy can improve the startup quality of the Dual Clutch Transmission vehicle effectivelySet up simulation model for DCT shift process based on the overlap character-istic of the DCT and the control strategy for upshift and downshift of DCT. The resultsdedicate that the two clutches quickly separate and accurately joint,and the Dual Clutch Transmission vehicle ensures that the requirements of the smoothness and speed in shifting process.Dual clutch transmission has many advantages, such as high transmission efficiency, compact installation space and will have an important status in automatic transmission family.