Abstract: Based on the five-speed dry dual clutch transmission(DCT) which have been independently developed, the issue of torque coordinating control between engine and twin clutches is been discussed from the system level in order to adequately reflect the driver’s intension and improve the shift quality of DCT, calculation formulas of engine speed and clutch delivered torque during the shifting process are been induced also. Considering the characteristic of physical configuration, five degrees-of-freedom(DOF) shifting dynamics equations of DCT are been established, after simplifying two-DOF model in the stage of slip-friction and one-DOF model in the stage of in-gear stable operation are been respectively attained. According to the requirements of the shift quality, the quantitative control objectives of shifting process are been proposed. Based on the analysis of torque and speed characteristics of engine and twin clutches during the shifting process, the fuzzy time decision and the model-based torque coordinating control strategy are been produced. Simulation model of DCT shifting control is been established on the Matlab/Simulink software platform, upshifting process and downshifting process are been simulated and analyzed under different driving intension. Real vehicle chassis dynamometer test has also been done. Simulation and experiment results show that the proposed model-based torque coordinating control strategy can not only effectively reflects the driver shift intention and improve the shift quality of DCT, but also be adaptable to the various shifting conditions and has strong robustness.

Key words: Five-speed dry dual clutch transmission, Fuzzy shifting time decision, Model-based torque coordinating control, Real vehicle chassis dynamometer test