考虑弹簧迟滞特性的干式离合器滑摩状态下自动变速车辆纵向运动特性及控制方法

Adaptive cruise control is a key technology for intelligent transportation system, and the low-speed and creeping with stop & go cruise control are bottleneck problems for full conditions, full speed range cruise application. Taking an automated manual shift vehicle equipped with dry clutch as the research platform, this project investigates on the control method for creeping with stop & go under extreme conditions, especially on the vehicle longitudinal dynamic equation and clutch transmitted torque model. Estimation of clutch transmitted torque under the condition of medium/high slipping speed and continuous pulse position excitation and optimal evaluation method of trajectory tracking during clutch slipping process are the key scientific problems. With the establishment of a hybrid model meeting the vehicle startup and running steadily at the same time, discuss mode switching rules. On this base, study the multidimensional equation of clutch transmitting torque based on Coulomb’s friction model, and pay particular attention to the coupling relationship among clutch slipping speed, spring hysteresis characteristics and clutch transmitting torque. And then, analyze the characteristic and controllability of the clutch transmitting torque under the condition of continuous pulse position excitation, and determine the control state variables and the key factors. Finally, obtain the optimal adaptive control method and validate it through vehicle tests. The research results are of significance to improve the application level of automated manual transmission in the whole region and the automatic driving technology.

自适应巡航控制是智能交通系统的重要研究内容，低速巡航和起-停慢行巡航控制是实现全工况、全车速巡航的关键技术。本项目以配备干式离合器的自动机械变速车辆为对象，研究极限工况下的起-停慢行控制方法，重点关注车辆纵向动力学方程和离合器传递扭矩模型。中高速滑摩和连续脉冲式位置激励下离合器传递扭矩估计、离合器滑摩过程轨迹跟踪最优评价方法是关键科学问题。本项目旨在建立车辆起步阶段和低速行驶阶段的混杂动力学模型，探明阶段切换规律。研究以库仑摩擦模型为基础的多维离合器扭矩传递方程，揭示离合器传递扭矩与滑摩转速和弹簧迟滞特性的耦合规律，探讨连续脉冲式位置激励下离合器传递扭矩特性及可控性，突破离合器滑摩过程传递扭矩控制这一瓶颈问题，获取控制状态变量和关键影响因素，设计最优自适应控制方法，并通过台架和实车试验进行验证。研究成果对提高自主研发的自动机械变速器全地域应用水平和促进自动驾驶技术的发展有重要意义。

自动机械变速操控系统具有结构简单、传递效率高等优点，在重型商用车和重型越野车辆上被广泛采用。但是其采用的干式离合器传递扭矩受滑摩转速、压紧弹簧特性等影响较大，在车辆起步阶段和低速行驶阶段控制难度较大，是制约装备自动机械变速操控系统实现低速巡航和起-停慢行巡航的关键技术难点。本项目针对上述背景，建立了离合器扭矩传递模型及参数识别，以及整车动力学建模、完成了车辆纵向动力学混杂模型的建立和面向编队行驶的弦稳定性分析、设计了低速工况离合器控制算法，进行了仿真和实车试验研究，证明了模型和控制算法的合理性和有效性。通过本项目的研究，获得了压紧力、转速差以及温度与离合器摩擦系数的拟合关系，车辆纵向动力学混杂模型以及面向编队行驶的弦稳定性模型，并通过台架和实车试验积累了大量的原始试验数据，支撑了本项目的完成，并为下一步从事相关研究工作打下基础。同时，基于本项目的研究，发表SCI论文4篇，EI论文6篇，出版专著1部，培养博士研究生2名，硕士研究生8名。研究成果对提高自主研发的自动机械变速器全地域应用水平和促进自动驾驶技术的发展有重要意义。