Gear-Shift Control Strategy for a 6 Speed Wet-Type DCT

It is crucial to control the engagement of the in-coming clutch and the disengagement of the off-going clutch for the gear-shift process in order to improve the shift quality of dual clutch transmission (DCT). Aiming at the development of a 6 speed wet-type DCT, three evaluation indices of shift quality including shift time, shift jerk and friction work per unit area, were analyzed in detail. And the torque and the engine speed control strategies for the upshift and the downshift processes were discussed respectively through dividing the gear-shift process into 5 stages. The proposed strategies have been evaluated via simulation experiments of the upshift from gear position 1 to gear position 2 and downshift from gear position 2 to gear position 1, under wide-open throttle respectively. The results show that the proposed strategies can get short shift time and acceptable ride comfort, meanwhile prolong the service life of the friction elements of dual clutches.