Pre-shift Control And Simulation Of Dual-clutch Automatic Transmission

Dual-clutch automatic transmission (DCT-Dual Clutch Transmissions) is a new type automatic transmission in automotive transmission field. DCT not only combines the advantages of manual transmission (MT) and conventional automatic transmission (AT), but also converses transmission ratio without power interruption, thus reduces the shift time and increases the shift quality. In comparison with AT, vehicles with DCT have the same performance in convenience and driving comfort, but more excellent in fuel economy. In addition, DCT is less costly to manufacture since it shares similar structure and components with MT. Due to its advantages, DCT has attracted extensive development interests in the automotive industry in recent years. In this paper, the research object was focused on the synchronizer of a Dual-clutch automatic transmission. Pre-shift control method and control strategy of wet Dual-clutch automatic transmission were investigated deeply. The main research work is as follows:â‘ The structure of wet Dual-clutch transmission synchronizer was analyzed; The force condition of the synchronizer in the process of gear shifting and gear picking were studied; the force formulas of corresponding action point and segment are acquired.â‘¡The slipping frictional power in the synchronization process was analyzed, formulas of the synchronization capacity were derived, and the range of speed difference between the two ends of synchronizer was calculated. After calculating the allowed angular velocity difference between the two ends of the synchronizer in the process of pre-shifting, the work range table of synchronizer was acquired.â‘¢The influence factors of the pre-shift synchronous force and pre-shift time were analyzed; The control strategy of pre-shift force was formulated. The simulation model of pre-shift was established, and simulations and studies of pre-shift time in different gears were carried out.â‘£The impacts of towing torque to pre-shift were analyzed; The pre-shift control strategy was studied; finally, simulation verification of the pre-shift control strategy was carried out.