两栖车抗倾能力下降原因分析与改善措施研究

为了尽可能减小两栖车辆在水中航行时车轮所产生的涡流损失,对两栖车车轮收放功能进行了改进,采用降低两栖车辆悬架系统定位点的方法来增大车轮的收起空间。采用ADAMS／CAR对悬架系统定位点降低后的前悬架及整车性能进行仿真,分析了悬架系统定位点降低所引起的抗倾能力下降的原因。采用增大螺旋弹簧刚度和稳定杆直径的方法来增大悬架的侧倾角刚度和纵向刚度,提高车辆的抗倾能力。仿真分析表明,改进后的两栖车仍具有不足转向特性,并且具有良好的行驶平顺性。     

两栖车辆车轮收起前后阻力对比并行计算分析

为了分析两栖车辆车轮收起前后粘性阻力的变化,利用流体动力学进行仿真分析。在前处理器Gambit中建立两栖车辆的物理模型,结合计算速度和计算精度,对流场采用分区网格划分。利用流体体积函数(VOF)多相流模型、k-ε两方程湍流模型,对车轮收起前后的两栖车辆的粘性绕流场进行了数值模拟。为了提高计算速度,数值模拟采用了并行算法。仿真结果表明:车轮收起后,粘压阻力可减小33%,从而证明收起车轮可减小两栖车辆在水中航行时的阻力。     

差动转向六轮车悬架系统现状综述

调研当前军用差动转向及微型差动转向六轮车悬架系统,比较其悬架参数并简要分析其悬架形式优缺点。比较传统六轮车与差动转向六轮车转向过程,结合差动转向六轮车ADAMS仿真曲线,分析差动转向时车轮力学特性。差动转向悬架系统与传统悬架差异较大,有必要深入研究差动转向六轮车悬架系统。     

基于ADAMS的自动引导车前悬架系统优化设计

应用ADAMSNIEW建立了自动引导车的不等长双横臂式独立前悬架仿真模型,采用单轮激振方式对模型的动力学特性进行仿真分析.主要分析了在车轮上下跳动过程中车轮定位参数的变化趋势,车轮各定位参数对侧向滑移量的影响,这些研究为车轮定位参数的初始设计提供了技术依据.并应用ADAMS软件对此模型进行优化设计,优化的最终目标是获得车轮跳动过程中车轮的最小侧滑量,以便改善悬架系统性能和减小轮胎磨损,提高自动引导车的安全性、转向轻便性、操纵稳定性及燃油经济性.     

汽车防抱死系统与主动悬架联合控制研究

提出了一种汽车防抱死系统与主动悬架联合控制策略。将采用光滑滑模控制的防抱死系统同采用反向递推控制的主动悬架相结合,在车辆制动时,主动悬架调节作用在车轮上的垂直载荷,使车轮的垂直载荷在车轮滑移率达到最优时也相应增加,从而获得最大的制动力。在MATLAB/Simulink仿真环境下,建立了仿真模型并进行了车辆制动模拟试验。试验结果表明,采用联合控制的车辆,在保证车辆制动稳定性的同时能够获得最大的地面制动力,从而显著提高了车辆的制动效能。     

基于CATIA的麦弗逊悬架运动仿真分析

汽车悬架是影响汽车性能的重要部件之一,悬架的运动学性能直接影响操纵稳定性等汽车使用性能,悬架的性能取决于悬架的开发设计水平。利用电子样机技术对汽车悬架进行动态仿真分析,与传统的设计方法相比,可以缩短开发周期,同时降低开发成本。利用CATIA软件建立了带转向系统麦弗逊悬架的运动学模型,通过对模型中相应关节处施加运动约束,再进行运动学仿真分析,从而获得车轮跳动时车轮定位角的变化和轮胎包络,为整车后续设计提供了理论数据。     

FSAE赛车车架系统的模态分析及动态性能评价

针对FSAE赛车在行驶过程中车架受到的来自路面不平度、车轮动态不平衡和电机振动的激励从而导致的共振破坏的问题,以及为了合理安排负载在车架上的安装位置,通过采用ANSYS中的Block Lanczos法对车架系统进行了自由模态分析和约束模态分析(约束模态分析的对象包括"悬架-车架"系统、"车架-负载"系统和"悬架-车架-负载"系统)。通过对比分析车架的自由模态分析振型特点与3种车架系统的约束模态分析振型特点,得出了"悬架-车架-负载"系统的振型来源于车架子系统(车架,"悬架-车架"系统和"车架-负载"系统)的振型,提出了"悬架-车架-负载"系统的改进方案以提高整车动态性能。通过"悬架-车架-负载"系统的柔性约束模态试验,验证了仿真数据的正确性。研究结果表明,该车架能满足赛车手舒适性要求,能避免共振破坏的发生。     

模糊控制技术及其在汽车半主动悬架中应用

建立了４自由度汽车半主动悬架系统的数学模型,采用模糊控制策略,对半主动悬架系统进行了计算机仿真。在此基础上,设计开发了以８０９８单片机为主控器件的半主动悬架模糊控制系统,并对自行研制的半主动悬架系统进行了实车道路试验。仿真计算和实车试验结果较吻合,其结果均验证了半主动悬架系统在减少振动,提高汽车行驶平顺性方面要优于传统被动悬架系统。     

全地形车前悬架系统对操纵稳定性的影响研究

全地形车是指适合各种地形的交通工具,具有良好的机动性,操纵稳定性是全地形车重要性能之一,而悬架的定位参数对全地形车的操纵稳定性具有较大的影响。以全地形车前悬架系统为研究对象,在ADAMS/Car中建立了其参数化模型,通过仿真得出全地形车前悬架参数随车轮上下跳动的变化曲线。分析了前轮定位参数(包括前轮外倾角、前轮前束角、主销内倾角、主销后倾角)对操纵稳定性的影响,找出优化目标,调整悬架硬点参数,进行参数优化设计,最终得到满足悬架和整车设计要求的悬架系统。研究结果表明,采用该方法研究悬架系统对操控稳定性的影响是可行的。     

基于ADAMS的双横臂独立悬架的仿真分析及优化设计

采用虚拟样机技术,借助于ADAMS软件这个操作平台,针对某型车双横臂独立悬架定位参数变化过大,建立了双横臂独立悬架模型,并进行了运动学仿真分析,评价了悬架数据的合理性。利用ADAMS/Insight选取了适当的硬点坐标作为优化变量,采用统一目标法将多目标函数转化为单目标函数并在ADAMS/View中对车轮定位参数进行优化,进一步改善悬架系统的性能,以提高产品开发的质量。     

Novel Evaluation Method of Vehicle Suspension Performance Based on Concept of Wheel Turn Center

The current research of suspension performance evaluation is mixed in the evaluation of vehicle handling and ride comfort. However, it is lack of a direct and independent evaluation method for suspension performance. In this paper, a novel wheel turn center method is proposed to evaluate the suspension performance. This method is based on the concept and application of wheel turn center(WTC) and sprung mass turn center(SPTC). The vehicle body and each wheel are regarded to be independent rigid bodies and have their own turn centers which reflect respective steering motions and responses. Since the suspension is the link between vehicle body and wheels, the consistence between the sprung mass turn center and the wheel turn center reflects the effect and performance of the suspension system. Firstly, the concept and appropriate calculation method of WTC and SPTC are developed. Then the degree of inconsistence between WTC and SPTC and the time that they achieve consistence, when the vehicle experiences from transient steering to steady steering state, are proposed to evaluate suspension performance. The suspension evaluation tests are conducted under different vehicle velocities and lateral accelerations by using Car Sim software. The simulation results show that the inconsistence of steering motion between vehicle body and wheels are mainly at high speeds and low lateral accelerations. Finally, based on the proposed evaluation indexes, the influences of different suspension characteristic parameters on suspension performance and their matches to improve steering coordination are discussed. The proposed wheel turn center method provides a guidance and potential application for suspension evaluation and optimization.     

人-椅8自由度车辆系统的平顺性和稳定性研究

文中在Matlab/Simulink中搭建了人-椅8自由度车辆系统仿真模型,在仿真分析时考虑汽车前、后轮之间的延迟性,以路面随机信号作为输入激励,研究了汽车平顺性的时频特性,且分别通过4个轮胎的输入激励研究了汽车的稳定性.研究结果表明:路面输入为随机信号时,车身垂直加速度,车身俯仰角加速度,人-椅垂直加速度,前、后悬架...     

连通式油气悬挂车辆三种行驶状况下数学模型的建立

介绍了连通式油气悬挂车辆在正常行驶、两侧车轮载荷不同及车辆转弯时三种不同状态下数学模型的建立。同独立式油气悬架相比较,能够大大增强整车的侧倾角刚度,减小车辆转弯时车架的侧倾角。通过不同的连接方式,还可以起到抗点头作用,从而提高了车辆行驶的稳定性。     

LMS自适应主动控制汽车悬架系统试验研究

以汽车操纵稳定性及行驶平顺性为控制目标，确定汽车系统的簧上质量加速度、车轮动载荷、悬架动挠度为具体评价参数。选择LMS自适应滤波算法，通过调整自适应滤波器的权系数使二次性能指标最小，根据单个样本方差的负梯度来调节权系数，得到控制输出。针对简化的汽车模型，在路面信号作为激励源的仿真研究过程中，算法对悬架系统的振动控制收到了较好的效果。在两自由度的悬架系统试验台架上进行了试验研究，结果进一步证明该算法的有效性，表明LMS自适应控制策略在主动悬架系统中的应用切实可行。     

电动汽车麦弗逊前悬架设计及参数优化

根据整车设计参数及悬架设计理论,设计某款电动汽车的麦弗逊前悬架。基于UG/Motion利用UG的开放接口开发相应的软件系统,实现麦弗逊前悬架运动学仿真模型的参数化设计、前轮外倾角与前束角的匹配设计和前悬架系统的运动学仿真分析;通过与ADAMS的仿真结果相对比,验证系统的正确性;将遗传优化算法与多体运动学分析方法相结合,以前轮定位参数的变化量最小和车轮侧向滑移量最小为优化目标对麦弗逊前悬架的设计参数进行优化,通过对比初始设计与优化设计的仿真结果,验证优化方法的有效性。优化分析显示,麦弗逊前悬架摆臂前后点坐标的变化,对前轮定位参数及车轮接地点滑移量随车轮跳动量的变化曲线都有影响。     

一种客车后独立悬架上的传动装置

客车独立悬架是把客车车身和车轮弹性地连接在一起,它是汽车上的重要总成之一。悬架的主要作用是传递作用在车轮和车身之间的一切力和力矩,比如支撑力、制动力和驱动力等,并且缓和由不平路面传给车身的冲击载荷、衰减由此引起的振动、保证乘员的舒适性、减小货物和车辆本身的动载荷,同时,其车轴被分成两段,每只车轮用螺旋弹簧独立地安装在车架(或车身)下面,当一边车轮发生跳动时,另一边车轮不受波及,客车的平稳性和舒适性好。独立悬架已成为一种发展大趋势。     

General Torsional Stiffness Matching of Off-road Vehicle

Increasing frame torsional stiffness of off-road vehicle will lead to the decrease of body torsional deformation, but the increase of torsional loads of flame and suspension system and the decrease of wheel adhesive weight. In severe case, a certain wheel will be out of contact with road surface. Appropriate matching of body, flame and suspension torsional stiffnesses is a difficult problem for off-road vehicle design. In this paper, these theoretically analytic models of the entire vehicle, body, frame and suspension torsional stiffness are constructed based on the geometry and mechanism of a light off-road vehicle's body, frame and suspension. The body and frame torsional stiffnesses can be calculated by applying body CAE method, meanwhile the suspension's rolling angle stiffness can be obtained by the bench test of the suspension's elastic elements. Through fixing the entire vehicle, using sole timber to raise wheels to simulate the road impact on a certain wheel, the entire vehicle torsional stiffness can be calculated on the geometric relation and loads of testing. Finally some appropriate matching principles of the body, frame and suspension torsional stiffness are summarized according to the test and analysis results. The conclusion can reveal the significance of the suspension torsional stiffness on off-road vehicle's torsion-absorbing capability. The results could serve as a reference for the design of other off-road vehicles.     

基于组合优化策略的动车组悬挂参数优化设计

为快速获得改善车辆横向平稳性的最优悬挂参数,提出基于自适应模拟退火算法和非线性序列二次规划算法的组合优化策略对动车组悬挂参数进行优化设计。建立动车组动力学模型,利用最优拉丁超立方抽样方法选取对横向平稳性影响较大的悬挂参数作为设计变量;以横向平稳性为目标函数构建Kriging代理模型,并利用可决系数检验代理模型精度;采用自适应模拟退火算法对代理模型进行全局范围内初步寻优,在初步最优解的基础上采用非线性序列二次规划算法进行局部空间精确求解。研究结果表明,基于Kriging代理模型和组合优化策略的优化效率明显提高,车辆横向平稳性得到显著改善,并且优化前后运行稳定性均满足要求。     

Skyhook-based semi-active control of full-vehicle suspension with magneto-rheological dampers

The control study of vehicle semi-active suspension with magneto-rheological (MR) dampers has been attracted much attention internationally. However, a simple, real time and easy implementing semi-active controller has not been proposed for the MR full-vehicle suspension system, and a systematic analysis method has not been established for evaluating the multi-objective suspension performances of MR full-vehicle vertical, pitch and roll motions. For this purpose, according to the 7-degree of freedom (DOF) fullvehicle dynamic system, a generalized 7-DOF MR and passive full-vehicle dynamic model is set up by employing the modified Boucwen hysteretic force-velocity (F-v) model of the MR damper. A semi-active controller is synthesized to realize independent control of the four MR quarter-vehicle sub-suspension systems in the full-vehicle, which is on the basis of the proposed modified skyhook damping scheme of MR quarter-vehicle sub-suspension system. The proposed controller can greatly simplify the controller design complexity of MR full-vehicle suspension and has merits of easy implementation in real application, wherein only absolute velocities of sprung and unsprung masses with reference to the road surface are required to measure in real time when the vehicle is moving. Furthermore, a systematic analysis method is established for evaluating the vertical, pitch and roll motion properties of both MR and passive full-vehicle suspensions in a more realistic road excitation manner, in which the harmonic, rounded pulse and real road measured random signals with delay time are employed as different road excitations inserted on the front and rear two wheels, by considering the distance between front and rear wheels in full-vehicle. The above excitations with different amplitudes are further employed as the road excitations inserted on left and right two wheels for evaluating the roll motion property. The multi-objective suspension performances of ride comfort and handling safety of the proposed MR full-vehicle suspensi     

基于CATIA/ADAMS的麦弗逊悬架运动分析

悬架是汽车的车架与车桥或车轮之间的传力连接装置,汽车悬架类型的选择和悬架参数的差异对汽车的操纵稳定性和行驶平顺性具有重要的影响。主要分析了麦弗逊悬架的结构特点,并通过CATIA软件建立麦弗逊悬架的三维立体简化模型,并运用ADAMS软件对其进行仿真分析,了解悬架的运动状态和过程,并得出相关结论,确定车轮定位参数的选择范围,以及悬架的优化设计方法。