中文摘要：

基于自主开发的6速干式双离合器自动变速器（Dual clutch transmission,DCT）,提出基于极小值原理的双离合器联合起步过程发动机和双离合器转矩协调最优控制算法。在起步滑摩阶段,以滑摩功和冲击度为性能指标,在反映驾驶员意图的终端约束下,采用极小值原理和改进的发动机恒转速控制,研究并确定起步过程中双离合器,发动机转矩及其转速。根据起步控制目标,确定分离离合器分离条件和离合器的转矩分配关系。在需求转矩切换阶段,将发动机输出转矩平滑切换到驾驶员需求转矩。在Matlab/Simulink软件平台上,搭建DCT车辆双离合器联合起步控制仿真模型,对不同驾驶意图和起步档位下DCT车辆的起步过程进行仿真。结果表明,所提出的基于极小值原理的发动机和双离合器转矩协调控制策略,有效地保证双离合器联合起步品质,反映起步意图,延长离合器使用寿命。将所得的离合器最优转矩控制律转化为离合器位置控制律,在离合器伺服控制试验台架上进行离合器位置闭环控制,得到较好的跟踪效果。

英文摘要：

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.