【作者】 余淼；

【导师】 黄尚廉；

【作者基本信息】 重庆大学 ， 仪器科学与技术， 2003， 博士

【摘要】 随着国民经济飞速发展、高速公路网全面建设以及生活水平极大提高，汽车逐渐融入到人们工作生活之中，成为不可或缺的交通工具，人们对汽车的行驶平顺性和安全性提出更高的要求。悬架是影响汽车性能的关键部件，采用能够根据路面情况和车辆运行状态进行实时控制的智能悬架是提高汽车的平顺性和安全性的一条重要途径。磁流变半主动悬架利用磁流变技术实现了阻尼实时控制，具有优良的可控性、很宽的动态范围、较高的响应速度，很低的功耗，相对简单的结构，成为目前智能悬架领域的研究热点，受到全球汽车制造商的青睐。本文应用理论分析、数值仿真和道路试验的方法，对磁流变阻尼器的动态特性、汽车磁流变半主动悬架的动力学特性、半主动悬架控制策略以及控制系统设计与实现进行了研究。具体工作包括以下几方面： （1）阐述了智能悬架研究的重要意义，回顾了智能悬架研究历史和进展，综述了磁流变液、磁流变阻尼器和汽车磁流变半主动悬架的研究现状和存在的问题，针对汽车磁流变半主动悬架目前存在的问题提出了本文将要开展的主要工作。（2）应用流体力学理论，根据Newton流体或Bingham流体的本构方程，利用环形通道模型和平板模型推导出磁流变阻尼器的流变学方程和阻尼力计算公式，分析了阻尼器的示功特性和速度特性；按照国家标准和微型汽车的技术要求，利用MTS电液伺服测试系统对本文采用的磁流变阻尼器进行了示功特性、速度特性和温度特性进行了测试；比较了理论阻尼力与试验测试得出的阻尼力变化规律，分析了产生误差的主要原因。（3）阐述了汽车悬架系统的性能评价的方法和指标，建立了随机路面的不平度输入模型和1/4车辆悬架动力学模型，推导出了簧载质量振动加速度、悬架动挠度和轮胎动载荷相对于路面输入的传递函数，并通过数值仿真研究了不同行驶速度和不同等级路面下长安微型面包车的悬架频域响应以及悬架参数对悬架传递特性的影响，以及脉冲输入下被动悬架的时域响应。（4）建立了磁流变半主动悬架模型，阐述了天棚阻尼控制策略、模糊控制策略原理方法，提出了一种利用小波分解车身振动加速度信号，判断当前振动频率组成，从而确定阻尼力大小的控制策略--小波频域控制策略，设计了用于汽车半主动悬架的天棚阻尼控制器、以簧载质量绝对速度和簧载质量与非簧载质量相对速度为输入量的模糊控制器以及以簧载质量垂直振动加速度为输入量的小波频域控制器，并利用Matlab软件及相应的工具箱建立了磁流变半主动悬架仿真系统，<WP=4>通过数值仿真分析了采用以上控制策略后磁流变半主动悬架在不同行驶速度和不同等级路面下的悬架频域响应，以及脉冲输入下半主动悬架的时域响应，最后根据控制效果对三种控制策略进行了比较和评价。（5）设计和实现了磁流变半主动悬架控制系统，包括基于DSP的控制器、抗混滤波器、硬件积分器、电流驱动器以及控制软件等关键部件和技术，并且对试验用车—“长安之星”微型面包车进行了半主动控制改装。根据汽车平顺性随机输入试验要求，平顺性测试和数据分析系统由B&K公司的平顺性座垫、电荷放大器、数据采集箱和笔记本计算机及分析软件组成，选择重庆市长滨路作为试验道路，分别在30km/h、40 km/h、50 km/h的行驶速度下测试了驾驶员座位处的加速度信号。半主动悬架的测试结果与相同条件下被动悬架的测试结果进行了加速度功率谱和加速度均方根值的比较，然后根据测试结果对模糊控制策略和小波频域控制策略进行了比较和评价。最后总结了全文的研究工作，介绍了论文的特色与创新之处，指出了近期有待深入研究的问题。更多还原

【Abstract】 With the rapid development of national economy, the overall construction of expressway network and the great improvement of people’s living standard, automobiles have gradually come into people’s life and work, and become an indispensable means of transportation. Meanwhile, people have made greater demands on the comfort and security of automobiles. The suspension system is a critical component that can influence the automotive performance. The intelligent suspension system has real-time control according to the road surface conditions and the state of automobile’s motion. Its adoption is an important approach to improving automotive comfort and security. Magnetorheological (MR) semi-active suspension applies MR technology to carry out the real-time control of its damp. Due to its good controllability, wide dynamic range, rapid response speed, low operating power requirement and comparatively simple structure, MR semi-active suspension has become one of the central research subjects in intelligent suspension field, and has also received considerable attention of global automobile manufactures. In this paper, the methods of theoretical analysis, numerical simulation and road testing are applied to study the dynamical characteristics of MR damper and semi-active suspension, the control strategies and the control system’s design and realization of semi-active suspension. The main contributions of the dissertation include the following:1. The paper expounds the significance of the intelligent suspension research, reviews its history and development, summarizes the present situation and existing problems of MR fluids, MR dampers and MR semi-active suspension, and puts forward the main work aimed at the present problems of automotive MR semi-active suspension. The rheology equations of MR damper and the computation formula of damping force are derived from hydrodynamics theory, based on Newton fluid model or Bingham fluid model，flowing in annular duct or in parallel duct. And the force-displacement and force-velocity characteristics are also analyzed in this paper. In accordance with national standard and the technical demands for mini-automobiles, the MTS electric- liquid servo testing system is used to test the force-displacement 、force-velocity and force-temperature characteristics of the MR damper adopted in the paper. The change rules of theoretical damp<WP=6>2. force with that of tested damp force are compared, and also the main cause of the error is analyzed.3. The method and indicators used to evaluate the performance of the automotive suspension system are discussed. The road profile input model of random road surface and the dynamic model of quarter-car suspension is established. The transfer functions of sprung mass acceleration、suspension deflection and tire load relative to road disturbances are derived. With the numerical simulation, the suspension response in frequency domain of the mini-microbus at different speeds and on roads of different levels, and the influence of suspension parameter on the suspension transfer characteristic, as well as the time domain response of passive suspension for the impulse input are studied in the paper.4. The MR semi-active suspension model is established. The theoretical method of sky-hook control strategy and fuzzy control strategy is expounded. A new control strategy-the wavelet frequency control strategy is put forward. This strategy decomposes automotive vibration acceleration signal utilizing wavelet transform to judge the composition of present vibration frequency, thus to determine the magnitude of damping force. The sky-hook controller for vehicle semi-active suspension, and the fuzzy controller with the input of sprung mass absolute speed and the comparative speed between sprung mass and unsprung mass，wavelet frequency controller with the input of sprung mass vertical vibration acceleration are designed. MR semi-active suspension simulation system is established by using Matlab software and its corresponding toolboxes. After adopting the abo更多还原