中文摘要：

分别对工程车辆传动系统中的发动机、工作油泵、液力变矩器、自动变速器进行了建模分析，建立了传动系统模型并推导出传动系统动力学方程．通过对自动变速器离合器换挡过程分析，利用解析法推导出换挡过程中变速箱输出角速度、转矩与发动机角速度、发动机油门开度、变矩器变矩系数之间的数学表达式，得出发动机、液力变矩器参数对换挡品质的影响效果．为提高换挡品质，分别采用缓冲控制、定时控制以及综合控制方法对工程车辆发动机——传动系统进行整车控制，并进行了仿真试验．结果表明，缓冲控制和定时控制策略能不同程度地改善工程车辆传动系统的换挡品质、综合法效果更好．

英文摘要：

The mechanical models were developed for engine, working pump, torque converter and automatic transmission in the transmission system of construction vehicle, and the dynamical equation was deduced. To describe the shift characteristics, the torque and motion of the clutches of automatic transmission were discussed during shifting. The relations were derived analytically among the angular velocity, torque of gearbox, rotational velocity, throttle opening of engine and torque converter quotient. The impact of the parameters of engine and torque converter on shift quality was derived. To improve the shift quality, the cushion valve control, timing control and their combination control for engine-transmission system were developed. Finally, a simulation test for transmission system was carried out to validate the availability of control algorithm and to test the integrated performance of shift quality. The results show a significant improvement in terms of shift quality by applying valve control, timing control and their combination control.