中文摘要：

为了分析半挂汽车列车闭环系统侧向稳定性,建立了具有时间延迟的驾驶员模型,采用准牛顿最优算法确定了驾驶员参数,以具有反应延迟的驾驶员模型和半挂汽车列车三自由度模型的耦合系统为研究对象,分析了系统参数对系统侧向稳定性的影响。应用一种数值寻根法分析了系统的临界车速。结果表明：减小驾驶员反应延迟时间、保持适当的负载量和行驶车速,对提高半挂汽车列车侧向稳定性有明显作用。

英文摘要：

To analyze lateral stability of tractor-semitrailer closed loop system, a driver model with time-delay was developed Quasi-Newton optimization method was used to determine the parameters of driver. A coupling system composed of driver model with time-delay and 3-degree-of-freedom model of tractor-semi trailer was suggested to study the effect of parameters to lateral stability of system. A roots-locating numerical method was used to identify critical speed The results show that reducing time delay and keeping tractor-semitrailer running in appropriate speed and load play important role in improving lateral stability of tractor-semitrailer closed loop system.