基于自主开发的5速干式双离合器自动变速器(Dual clutch transmission,DCT),为充分反映驾驶员意图并改善DCT车辆的起步性能,从系统层面探讨发动机与离合器间的协调控制问题,量化并给出起步过程发动机转速及离合器传递转矩的计算公式。考虑该5速干式DCT物理结构特征,建立4自由度起步动力学方程,并将其简化分别得到2自由度滑摩过程模型和单自由度在挡运行模型。借鉴预测控制思想并采用遗传算法,在线滚动优化确定发动机转速及车速目标跟踪曲线,并设计滑模变结构起步协调控制策略。在Matlab/Simulink软件平台上,对不同驾驶意图DCT车辆的起步性能进行仿真,在自行搭建的DCT电控单元硬件在环仿真试验台架上,对滑模变结构起步协调控制算法进行快速原型试验。仿真及试验结果表明,所设计滑模变结构伺服控制器不仅有效地体现了驾驶员起步意图,提高了DCT车辆起步性能,而且对车辆参数摄动具有较强的鲁棒性,同时可推广用于机械式自动变速器(Automated mechanical transmission,AMT)车辆的起步控制。
Based on the five-speed dry dual clutch transmission(DDCT) which is independently developed,the issue of coordinating control between engine and clutch is investigated from the system level in order to adequately reflect the driver's intention and improve the launch performance of car equipped with DCT,and engine speed and clutch delivered torque in the launch process are quantified and corresponding calculation formulas are derived also.Considering the characteristic of physical configuration,four degrees-of-freedom(DOF) launch dynamics equations of DDCT with single intermediate shaft are established,and two-DOF equations of slip-friction phase and one-DOF equation of in-gear stable operation phase are respectively gotten after carrying on simplification.Utilizing the predictive control thoughts and genetic algorithm,target tracing curves of engine speed and vehicle velocity are specified optimally online,slip mode variable structure(SMVS) servo control strategy of launch is designed to track these curves.Launch performance of prototype car with DCT is simulated under different driving conditions on the Matlab/Simulink software platform.The rapid prototyping experiments of SMVS launch strategy are conducted on the hardware-in-the-loop test bench of DCT control unit,which is built up independently.Simulation and test results illustrate that the proposed servo controller of SMVS not only effectively embodies driver's intention and improves the launch performance of DCT prototype car but also has strong robustness to parameters' variations of car,it can be applied for the launch control of automated mechanical transmission(AMT) in the meantime.