针对不同汽车行驶工况下动力传动系统的自由度会变化的情况,提出了动力传动系统分相建模方法。该方法根据有限状态机中相的概念将汽车动力传动系统的工作状态分为空挡滑摩相、空挡锁止相、在挡滑摩相和在挡锁止相4种相位,并给出了每种相下系统自由度的变化和驱动转矩的计算公式。同时,由于离合器摩擦模型对动力传动系统非线性特性的精确模拟具有重要影响,故建立了满足动力传动系统实时定步长仿真要求的摩擦模型。最后,在典型工况下,进行了模型仿真和实车试验。结果表明,仿真结果与试验结果基本一致,可用于动力传动系统在预开发阶段的性能匹配。
In view of that the degrees of freedom ( DOFs) of powertrain system vary in different driving con-ditions of vehicle,a phase-wise modeling scheme for powertrain system is proposed, in which the operation states ofvehicle powertrain system are divided into four phases based on the phase concept in finite state machine slippingphases and locked phases in both neutral and engaged states,with the changes of system DOF and driving torque calculation formula in each phase given. Then considering the important effects of clutch friction model on the accu-rate simulation of the nonlinear characteristics of powertrain system, a friction model meeting the requirements of fix-step real-time simulation of powertrain system is built,with both simulation and real vehicle test conducted. The re-sults show that the results of model simulation are basically consistent with test results and can be used for perform-ance matching of powertrain system in pre-development stage.