Abstract: For the self-developed five-speed dry dual clutch transmission(DCT), the coordinating and optimal control is proposed based on minimum principle to solve the problems of launching with two clutches. In the slipping phase, minimum principle and improved engine constant speed control are adopted to obtain the optimal clutch and engine torque and their rotating speed with the minimum jerk intensity and friction work as optimization indexes. Besides, the separation conditions of non-target gear clutch and the clutches’ torque distributing relations are determined by the launching control targets. In the torque switching phase, engine torque is converted to the driver’s demand level. Besides, the launching control strategies are simulated under the different launching conditions on the Matlab/Simulink. Simulation results validate that the proposed control strategies based on the minimum principle can effectively obtain an excellent launching quality, reflect the driver’s launching intention and extend the life span of twin clutches. The clutch optimal principles are then transformed into clutch position principles and the closed-loop control of clutch position is verified in test platform of clutch actuator as a result of achieving a preferable tracking performance.

Key words: improved constant engine speed control, launching with two clutches, minimum principle, six-speed dry dual clutch transmission(DCT), torque optimal and coordinating control