货车平顺性预测与优化

本文介绍了货车15个自由度振动模拟模型,以及平顺性预测与优化的方法。利用ARPO软件对某货车的平顺性进行了模拟分析,计算值与道路试验值比较吻合。ARPO软件可用于分析汽车结构参数对平顺性的影响,预测和优化汽车的平顺性。     

车辆随机输入的动态仿真和试验研究

按汽车行驶平顺性评价方法,应用MATLAB工具箱编制了针对五自由度汽车模型的随机输入动态仿真程序,通过仿真可直接获得给定测点的加权加速度均方根值分量的最大值和总加权加速度均方根值,仿真结果与随机输入行驶试验结果基本吻合,证明仿真方法是正确的,该程序可用于汽车悬架系统参数的设计和平顺性的评估。     

基于近似模型的车辆操纵稳定性及平顺性的优化研究

简述了基于近似模型的车辆操纵稳定性及平顺性的优化设计方法.利用多体动力学软件ADAMS/Car建立了某轿车整车多体动力学模型,并确定了车辆操纵稳定性及平顺性的评价目标.以悬架弹簧刚度、减振器阻尼特性和横向稳定杆刚度为设计变量,利用近似优化数学模型对该轿车进行了操纵稳定性和行驶平顺性的多目标优化计算.结果表明,近似模型技术对于汽车性能的平衡优化是一种十分有效的方法.     

Comfort enhancement by an active vibration reduction system for a flexible railway car body

In order to improve the ride comfort of lightweight railway vehicles, an active vibration reduction system using piezo-stack actuators is proposed and studied in simulations. The system consists of actuators and sensors mounted on the vehicle car body. Via a feedback control loop, the output signals of the sensors which are measuring the flexible deformation of the car body generate a bending moment, which is directly applied to the car body by the actuators. This bending moment reduces the structural vibration of the vehicle car body. Simulations have shown that a significant reduction in the vibration level is achieved.     

Comfort enhancement by an active vibration reduction system for a flexible railway car body

In order to improve the ride comfort of lightweight railway vehicles, an active vibration reduction system using piezo-stack actuators is proposed and studied in simulations. The system consists of actuators and sensors mounted on the vehicle car body. Via a feedback control loop, the output signals of the sensors which are measuring the flexible deformation of the car body generate a bending moment, which is directly applied to the car body by the actuators. This bending moment reduces the structural vibration of the vehicle car body. Simulations have shown that a significant reduction in the vibration level is achieved.     

基于频域加权性能指标和输出反馈的主动悬架控制策略研究

本文对传统的主动悬架线性二次型控制策略作了频域改进设计和研究。通过对有关平顺性的指标项进行频域加权。在不影响其它方面性能指标的同时，大大改善了车辆的平顺性，通过对几种不同型式的输出反馈的比较研究，得出了可行的控制策略。     

重型商用车驾驶室悬置结构对平顺性影响的试验研究

以某重型商用车驾驶室悬置系统为例,通过实车道路试验,研究了四弹簧,四气囊悬置减振系统的振动特性在A级路面和B级路面对车辆行驶平顺性的影响规律。试验结果表明,四气囊驾驶室悬置系统的平顺性整体优于四弹簧驾驶室悬置结构。     

汽车座椅舒适性的主观和客观评价研究

在对座椅机械结构及人体脊骨生理结构分析的基础上,从主观和客观两方面针对腰托对汽车座椅舒适性影响进行了理论和试验研究。研究表明腰托装置的设计及安装对人体的体压分布有显著影响,设计合理的腰托装置可明显改善汽车座椅的舒适性。     

基于正交试验的虚拟样车平顺性分析及参数选择

利用多体力学理论,在机械系统动力学分析软件ADAMS中建立了某车的整车多体力学模型。将虚拟样车在三维空间道路上进行平顺性仿真试验,通过正交试验方法研究了前、后悬架弹簧刚度及相关主要衬套等性能参数对汽车行驶平顺性的影响,并根据正交试验的结果优选了相应的设计参数。     

Heavy-duty vehicle modelling and longitudinal control

This paper addresses modelling, longitudinal control design and implementation for heavy-duty vehicles (HDVs). The challenging problems here are: (a) an HDV is mass dominant with low power to mass ratio; (b) They possess large actuator delay and actuator saturation. To reduce model mismatch, it is necessary to obtain a nonlinear model which is as simple as the control design method can handle and as complicated as necessary to capture the intrinsic vehicle dynamics. A second order nonlinear vehicle body dynamical model is adopted, which is feedback linearizable. Beside the vehicle dynamics, other main dynamical components along the power-train and drive-train are also modelled, which include turbocharged diesel engine, torque converter, transmission, transmission retarder, pneumatic brake and tyre. The braking system is the most challenging part for control design, which contains three parts: Jake (engine compression) brake, air brake and transmission retarder. The modelling for each is provided. The use of engine braking effect is new complementary to Jake (compression) brake for longitudinal control, which is united with Jake brake in modelling. The control structure can be divided into upper level and lower level. Upper level control uses sliding mode control to generate the desired torque from the desired vehicle acceleration. Lower level control is divided into two branches: (a) engine control: from positive desired torque to desired fuel rate (engine control) using a static engine mapping which basically captures the intrinsic dynamic performance of the turbo-charged diesel engine; (b) brake control: from desired negative torque to generate Jake brake cylinder number to be activated and ON/OFF time periods, applied pneumatic brake pressure and applied voltage of transmission retarder. Test results are also reported.     

摆臂橡胶件对汽车平顺性和悬架运动学影响的研究

针对摆臂橡胶件对汽车平顺性能和悬架运动学影响的问题,论文从多体动力学角度进行了研究。应用机械系统动力学仿真软件SIMPACK建立了考虑悬架摆臂橡胶件的某轿车整车动力学模型,选择里面的路面谱,设计三种实验方案分析摆臂橡胶件对汽车平顺性的影响,同时利用软件中的虚拟实验台研究了三种方案摆臂橡胶件对悬架运动学特性的影响。研究结果表明:摆臂橡胶件对汽车垂直振动0-5Hz频率的峰值影响比较大,大约在15%左右;通过合理选择橡胶件既可以改善车辆的平顺性且保证对悬架运动学影响不大。     

汽车一体化安全与碰撞预警安全技术

文章介绍了汽车一体化安全定义与组成,阐述了碰撞预警技术其通用的系统构架以及碰撞预警安全技术的应用现状.汽车一体化安全把汽车被动安全与主动安全有机结合,充分发挥主、被动安全措施的最佳效用,其代表技术是汽车碰撞预警安全,该技术已成为汽车安全领域新的研究热点和发展趋势.     

基于有限元分析的乘用车前纵梁安全设计

为提升车辆撞击事故乘员的安全性,从诱导孔个数、前纵梁材料和梁壁厚三个方面对汽车前纵梁进行了优化设计。将上述三个方面作为影响因素进行了正交试验设计,按照正交表在LS-DYNA当中进行了整车碰撞及台车试验,以头部损伤HIC值作为乘员损伤评价标准,通过极差分析确定了最优汽车前纵梁参数,提高了汽车碰撞中乘员的安全。     

Regenerative braking strategies,vehicle safety and stability control systems: critical use-case proposals

The sustainable development of vehicle propulsion systems that have mainly focused on reduction of fuel consumption (i.e. CO₂ emission) has led, not only to the development of systems connected with combustion processes but also to legislation and testing procedures. In recent years, the low carbon policy has made hybrid vehicles and fully electric vehicles (H/EVs) popular. The main virtue of these propulsion systems is their ability to restore some of the expended energy from kinetic movement, e.g. the braking process. Consequently new research and testing methods for H/EVs are currently being developed. This especially concerns the critical ‘use-cases’ for functionality tests within dynamic events for both virtual simulations, as well as real-time road tests. The use-case for conventional vehicles for numerical simulations and road tests are well established. However, the wide variety of tests and their great number (close to a thousand) creates a need for selection, in the first place, and the creation of critical use-cases suitable for testing H/EVs in both virtual and real-world environments. It is known that a marginal improvement in the regenerative braking ratio can significantly improve the vehicle range and, therefore, the economic cost of its operation. In modern vehicles, vehicle dynamics control systems play the principal role in safety, comfort and economic operation. Unfortunately, however, the existing standard road test scenarios are insufficient for H/EVs. Sector knowledge suggests that there are currently no agreed tests scenarios to fully investigate the effects of brake blending between conventional and regenerative braking as well as the regenerative braking interaction with active driving safety systems (ADSS). The paper presents seven manoeuvres, which are considered to be suitable and highly informative for the development and examination of H/EVs with regenerative braking capability. The critical manoeuvres presented are considered to be appropriate for examination of the regenerative braking mode according to ADSS. The manoeuvres are also important for investigation of regenerative braking system properties/functionalities that are specified by the legal requirements concerning H/EVs braking systems. The last part of this paper shows simulation results for one of the proposed manoeuvres that explicitly shows the usefulness of the manoeuvre.     

商用汽车动力传动系参数的优化设计研究

在汽车动力性和经济性模拟计算的基础上,以汽车能量利用率为目标函数,提出了一种商用汽车动力传动系统参数的优化设计方法,并采用该方法对某商用汽车动力传动系统进行了优化设计。模拟计算结果表明,经过优化传动系统参数,该车燃油经济性较原方案改善了3.82%,动力性提高了1.63%,从而验证了该方法的可行性。     

基于主动安全的轮间电控限滑差速器控制方法研究

论述了电控限滑差速器(ELSD)改善汽车动力学特性的原理,提出了基于提高汽车主动安全性的控制方法。该方法利用前馈与误差反馈控制相结合来控制车辆运动状态。反馈系数根据最优控制的方法确定。通过对所述控制系统的仿真研究,证明该系统在各种路面条件下均可明显改善汽车的操纵稳定性与主动安全性。     

电控气动式可调阻尼减振器的设计与应用

确定了电控气动式可调阻尼减振器在软、硬阻尼状态下的阻尼力设计目标.设计了以电磁阀和摆动气缸作为驱动机构的电控气动式可调阻尼减振器,通过仿真计算分析了该减振器的阻尼特性.研制了可调阻尼减振器样件并在试验台架上进行了性能测试.结果表明,除后减振器压缩阻力外.其余各项阻尼力试验值与仿真值的平均偏差小于7%,表明减振器的仿真模型有效.将该可调阻尼减振器装车进行的道路平顺性试验表明,与被动式减振器相比,采用可调阻尼减振器可使客车的行驶平顺性得到提高.     

摩托车振动舒适性测试系统开发及应用

为了分析评价摩托车振动舒适性,开发了基于USB2.0的可以脱离计算机进行独立数据采集的便携式数据采集器,并依据LABVIEW开发了数据处理分析系统,构建了摩托车振动舒适性测试分析系统。实车振动舒适性道路试验结果表明:系统性能可靠、稳定。     

田口法在汽车车身骨架刚度优化中的应用

以有限元限分析为基础，运用以正交设计为基础的田口法，在保持车身骨架整体质量不变的情况下，研究了提高车身整体扭转刚度和弯曲刚度的途径，探索了参数优化和拓扑优化相结合的统计优化方法。对双层客车所作的实例分析，证实了用田口结构优化是有效的。     

基于遗传算法车辆传动系统优化

本文采用遗传算法,以汽车的动力性和燃油经济性最优为目标,同时考虑一定的约束条件,对汽车的传动系参数进行优化,并通过仿真进行验证。