导　　师： 何仁

学科专业： 080204

授予学位： 博士

作　　者： ;

机构地区： 江苏大学

摘　　要： 随着高速公路的发展,汽车行驶速度越来越快,人们对汽车整体性能的要求也不断在提高,而转向系统对汽车整车行驶性能/(如操纵稳定性、行驶平顺性等/)有举足轻重的影响。作为直接影响汽车安全性能的重要部件之一,电动助力转向/(EPS/)系统在国内已从理论研究探索阶段逐步走向产品化阶段,本文依托江苏省“六大人才高峰”资助项目:轿车电动助力转向系统研究与开发,以EPS系统为研究对象,以现代非线性动力学分岔和混沌为理论基础,借助现代计算机技术,构建了装备EPS系统的整车操纵稳定性协同仿真虚拟试验框架,围绕着装备EPS系统的汽车非线性动力学、EPS系统的控制策略及其对整车操纵稳定性的影响等展开深入的理论分析和试验研究,具体研究内容如下: 首先考虑EPS系统干摩擦仿真模型以及魔术轮胎公式,建立驾驶员——装备EPS系统汽车闭环系统非线性操纵动力学模型,在此基础上运用现代非线性动力学理论对该模型在自治情况下进行非线性动力学特性分析和数值仿真,指出了分岔速度对闭环系统非线性运动稳定性的影响规律,分析了整车参数对闭环系统Hopf分岔速度的影响,着重研究了EPS系统参数对闭环系统Hopf分岔速度的影响。 其次从EPS系统控制的基本目标和常见的EPS系统控制策略入手,给出了直流电动机电流闭环PI控制的设计方法,并在此基础上应用混合灵敏度方法设计出了鲁棒H/_∞控制器。通过仿真结果分析表明基于PI电流环的混合灵敏度鲁棒H/_∞控制器能在较宽频带范围内增强地面低频信号、削弱高频信号和抑制转矩传感器的噪声,所设计的控制器有较强鲁棒性,助力跟踪能力和抗干扰能力,能有效改善车辆的转向回正特性,提供给驾驶员较为满意的路感,提高车辆的转向操纵性能。 第三、通过采用EPS系统电磁离合器PWM节能控制� With the high development of the expressway, the speed of modern vehicles is becoming faster and faster. The people's demand on the whole performance of vehicle is also becoming higher and higher. The steering system is effecting on the ride performance of vehicle more and more, such as handling and stability, ride comfort etc. Nowadays, as a most important safety system in the vehicle, EPS system technology has the trend of putting into production. The work is supported in part by grants from the project 'Study and Development on the Electric Power Steering System of automobile' sponsored by Jiangsu Province Six Kinds Talents Summit for providing financial support. This thesis focuses on the EPS system as investigated subject by using computer technique based on nonlinear dynamic theory foundation. The virtual co-simulation frame of vehicle equipped with EPS system handling and stability performance test is established. And research work is carried out to the vehicle of nonlinear dynamic equipped with EPS system, the control strategy of EPS system and its influences on vehicle both in theories and in experiments. The principal contents are as following: First, it has been established that driver-vehicle equipped with EPS system closed loop nonlinear handling dynamics simulation model by considering dry-friction simulink model of EPS system and Magic Formula of tire, which has been carried out on nonlinear dynamic characteristic analysis and numerical simulation under autonomous case. The influencing laws of bifurcation vehicle speed on motion stability of closed loop nonlinear system are on discussed. The influence of parameters of the automobile on bifurcation vehicle speed is also being studied. The influence of parameters of the EPS system on bifurcation vehicle speed is investigated on in details. Secondly, based on the basic target and familiar control strategy of EPS system, design methods of the classical PI controlling the current loop of the electromotor are researched and robust H/_∞controlle

关 键 词： 汽车 电动助力转向系统 分岔 混合灵敏度鲁棒 控制 协同仿真 虚拟试验 操纵稳定性

领　　域： [机械工程] [交通运输工程] [交通运输工程]