A Procedure for Optimization of Truck Suspensions

SUMMARY

The purpose of this paper is to develop a procedure based on covariance analysis and nonlinear programming techniques which can be used for the parameter selection of optimum truck suspensions. The procedure is applied to explore the differences in parameter selection caused by the changes in the frequency content of the road input or by changes in the criteria for optimization. The equations of motion for a tractor-semitrailer truck are cast in state space form. The road excitations are represented by the output of a white noise excited shaping filter taking into consideration the time delays between the different vehicle axles. Shape filters to represent human perception of vibration in both the vertical and longitudinal directions in the time domain are presented and realized in terms of state variables. The suspension parameters of the road-vehicle-human body system are optimized using a direct search algorithm.     

道路清障车的制动过程分析

建立了道路清障车拖带车辆制动工况力学模型，绘制了道路清障车拖带车辆行驶时的制动器制动力分配曲线Ｉ，分析了被牵引车结构参数的改变对制动过程的影响，并建议对这种轴荷变化的道路清障车应安装感载阀，以提高制动稳定性。     

Extended Ground-Hook - New Concept of Semi-Active Control of Truck's Suspension

This paper deals with the novel control concept, so called ground-hook for active and mainly semi-active suspension of vehicles with the ultimate objective to minimize the tyre-road forces and thus the road damage. The basic ground-hook concept is extended to the several variants which enable to decrease criteria of road damage as well as to increase driver's comfort for a broad range of road unevennesses. Parameters of control law are determined by the parameter optimization for generally nonlinear model. The influence and interaction of the damping rate limits and time constants of variable shock absorbers are also taken into account. The influence of implementation of more complicated truck models is also discussed.     

Extended Ground-Hook - New Concept of Semi-Active Control of Truck's Suspension

SUMMARY

This paper deals with the novel control concept, so called ground-hook for active and mainly semi-active suspension of vehicles with the ultimate objective to minimize the tyre-road forces and thus the road damage. The basic ground-hook concept is extended to the several variants which enable to decrease criteria of road damage as well as to increase driver's comfort for a broad range of road unevennesses. Parameters of control law are determined by the parameter optimization for generally nonlinear model. The influence and interaction of the damping rate limits and time constants of variable shock absorbers are also taken into account. The influence of implementation of more complicated truck models is also discussed.     

关于25t汽车起重机转向系统的选型设计

介绍了起重机转向系统的选型设计,利用MSC Adams软件对转向梯形机构进行了运动仿真,对其转向性能进行了优化,该起重机的道路试验结果表明所设计的转向机构性能符合设计要求。     

山区高速公路移动瓶颈效应对车流状态影响研究

我国高速公路大型货车混入率较高,山区高速公路交通流受移动瓶颈效应影响尤为突出。鉴于此,利用运动学波理论对因低速货车超车形成的移动瓶颈效应进行分析,应用vissim软件进行模拟仿真,通过对不同交通流状态下不同低速货车混入率的仿真结果分析,发现随着交通量以及货车混入率的增加,移动瓶颈效应对车流状态的影响呈加剧趋势,导致小客车行驶速度明显下降,并逐渐接近货车行驶速度。各慢行车队之间出现的较大空隙导致道路资源浪费,道路通行能力下降。该研究结论对深入研究山区道路通行能力具有重要指导意义。     

Optimal Suspension Parameter Distributions and Roadway Profiles for Isolation of Heavy Trucks

Heavy trucks are known to have ride problems and are difficult to isolate from roadway unevenness. Heavy trucks are rich in modal density and are stiffly sprung, a combination that makes isolation difficult. Due to their inherent mass, trucks create roadway unevenness as they move along a roadway. Each following truck is excited by the unevenness created by the preceding one, and the road condition worsens over time. It is shown that trucks create roadway profiles from which perfect isolation is possible by having the proper parameter distribution in the suspension units. One distribution is best for rigid body isolation and one is best for 'beaming' isolation.     

便携式汽车运动参数综合测试系统研究

以捷联式惯性导航原理为基础，研究短时惯性测量系统在汽车道路试验中的应用，提出了便携式汽车运动参数综合测试系统的方法，对系统配置，测试原理，计算方法，软件流程，惯性元件选择等重要问题进行了分析与讨论，并给出了计算机仿真结果。     

大功率型氢燃料电池重卡动力系统匹配设计

针对大功率型氢燃料电池重卡动力系统设计尚无成熟控制策略问题,提出了动力系统匹配设计中大功率型氢燃料电池保护优先的控制策略.根据该策略确定设计流程、零部件选型、参数匹配和计算.在此基础上,进行了动力系统构型优化,并基于稳态工况进行了燃料电池选型,同时综合考虑重卡实际工况特性和效率特性对氢燃料电池、动力电池和电机的功率以及...     

石太高速公路货运超载治理影响分析

在分析治超给石太高速公路所带来的影响的基础上,探讨了治超的意义及合理方法选择。建立在治超前后交通调查数据基础上,采用统计方法分析了货车车型变化特点;采用当量轴载换算方法分析了车辆对路面作用的变化;建立在典型路面构造基础上分析了道路养护成本的变化;建立在社会成本最低与公平基础上分析了治超的合理方法选择：证明了超载治理是正确的,但当前方法存在漏洞,成本偏高,长效激励机制不足。表明治超对公路部门具有巨大的直接效益,对汽车工业良性发展具有推动作用,今后应在保证不增加使用者总体负担基础上,将计重收费作为公路超限治理的主要政策选择。     

运用车流波动理论分析大货车混入对快速路车流的影响

随着城市对外交通需求的增加,大量大型货车进入快速路,大货车由于慢速引起后随车辆被迫减速,造成车流整体通行效率严重降低。运用车流波动理论确定大货车占道所引起车流的状态变化,定量分析大货车速度及其占道长度与堵塞时间、受阻车辆数之间的关系,从而说明大货车占道对车流延误的影响程度。通过定量分析明确划分大货车车道、快速路最低限速以及限制快速路大货车比例的重要性,从而为快速路混合车流管理提供依据。     

自然驾驶状态下重型工程车驾驶人驾驶稳定性分析

重型工程车行驶过程中事故风险大,发生恶性事故的概率高,易造成重大生命和经济损失,其运输安全管理问题面临挑战.为探究重型工程车驾驶人驾驶稳定性与相关影响因素之间的关系,开展重型工程车自然驾驶试验,提取车辆运动学、道路条件、驾驶人状态和工作时间等数据;采用速度均值和速度标准差表征驾驶人驾驶稳定性,以睡眠模式、道路线形、道路...     

左转圆曲线处避险车道流出角与引道设置

为了给设置于左转圆曲线处的避险车道流出角与引道长度设置提供参考,针对山区高速公路广泛采用的9.0 m宽制动床避险车道,考虑左转圆曲线半径和驶入速度的影响,进行了不同流出角度与引道长度的驾驶仿真试验研究。采用UC-win Road 9.0驾驶仿真平台,获取了不同场景下16名男性B照驾驶人由主线驶入紧急避险车道过程中的车辆运行特征数据。采用拟合回归的方法,分析了圆曲线半径和驶入速度对方向调整时间、最小转向半径、方向盘转角幅值、方向盘转角频率的影响,建立了各指标与圆曲线半径的定量回归关系模型,并对比了主线为直线时的试验结果。采用二阶聚类的方法对不同圆曲线半径条件下的引道与流出角度的设置水平进行分类,获取了适宜设置避险车道的初步条件。根据车辆的行驶稳定性,确定了左转圆曲线处避险车道流出角与引道的设计标准。研究结果表明：左转圆曲线处避险车道的流出角受圆曲线半径的影响,引道长度受圆曲线半径与驶入速度的影响;主线半径1 000 m及以上,流出角0°~5°,引道为6 s设计行程,流出角5°~10°,引道为9 s设计行程;条件困难时,紧急避险车道可设置于半径600~1 000 m的曲线处,流出角0°~5°,引道为9 s设计行程,流出角5°~15°,引道为12 s设计行程。     

高速公路隧道路段交通安全特性研究

基于高速公路隧道运行安全特性,对隧道路段定义进行改进。通过提炼交通事故特性参数对高速公路隧道路段和开放性道路的交通事故率进行对比,并对交通事故时间分布规律、空间分布规律、事故形态分布规律以及事故车型分布规律进行统计分析。研究结果表明,我国隧道路段事故率略高于开放性道路,而且隧道洞外事故率远高于洞内,隧道交通事故形态以追尾、刮擦和撞壁为主,火灾事故率极低,交通事故车型以小客车和大货车为主。     

车致疲劳损伤对钢-混凝土组合梁桥极限承载力可靠度的影响

钢-混凝土组合梁桥因其发挥了2种材料各自的优势,被广泛应用于中小跨径的桥梁结构中,而极限承载能力是评判其安全与否最直观的指标之一.为了对现役钢-混凝土组合梁桥的极限承载力进行更为准确的评估,提出一种确定钢主梁极限承载能力可靠度的新方法,该方法能考虑车辆荷载引起的疲劳累积损伤对钢主梁极限承载力的影响.首先建立了三维车桥耦...     

CA1046L轻型客货车冷气系统的试验研究

以配装冷气系统的CA1046L轻型客货车为例，通过对该车冷气系统试验，探讨了测点的选择、太阳辐射和路面覆盖层对汽车热负荷的影响。冷气系统性能试验可在室内进行整车台架试验，以避免其它因素影响；对于使用试验和可靠性运行试验，可在道路上进行。     

基于瞬态响应的某轻型卡车保险杠设计

保险杠是一种具有吸收、缓和外界冲击力,保护轻型卡车前部重要的安全装置。同时保险杠有很强的造型美观功能,是轻型卡车重要的外饰件之一。文章利用有限元计算和分析的方法对某轻型卡车保险杠内板进行瞬态响应分析,并进行结构优化。经过试验台架和道路试验满足设计要求,该方法对今后轻型卡车的保险杠设计有一定的指导作用。     

汽车零部件动态间隙测量试验研究

针对当前汽车零部件间动态间隙测量方法存在的问题,以SX3315DR326型自卸汽车为研究对象,对该车在空载和满载两种状态下,分别运行于三种路面和四种行驶工况(既:比利时路30km/h、平坦道路80km/h行驶、紧急制动和扭曲路)的主要零部件动态间隙进行测试分析,从而确定出汽车各运动部件在整车上的最大和最小间隙,为汽车设计整车布置提供准确依据。     

Dynamic simulation of train–truck collision at level crossings

Trains crashing onto heavy road vehicles stuck across rail tracks are more likely occurrences at level crossings due to ongoing increase in the registration of heavy vehicles and these long heavy vehicles getting caught in traffic after partly crossing the boom gate; these incidents lead to significant financial losses and societal costs. This paper presents an investigation of the dynamic responses of trains under frontal collision on road trucks obliquely stuck on rail tracks at level crossings. This study builds a nonlinear three-dimensional multi-body dynamic model of a passenger train colliding with an obliquely stuck road truck on a ballasted track. The model is first benchmarked against several train dynamics packages and its predictions of the dynamic response and derailment potential are shown rational. A geometry-based derailment assessment criterion is applied to evaluate the derailment behaviour of the frontal obliquely impacted trains under different conditions. Sensitivities of several key influencing parameters, such as the train impact speed, the truck mass, the friction at truck tyres, the train–truck impact angle, the contact friction at the collision zone, the wheel/rail friction and the train suspension are reported.     

基于负二项分布的高速公路交通事故影响因素分析

为分析高速公路交通事故的影响因素,构建基于负二项分布的事故分析模型,探究事故数与交通特性、公路线形及路面性能间关系.鉴于传统固定参数模型难以刻画各因素对事故风险影响的异质性,引入了随机参数建模方法.结果表明:相比于固定参数负二项模型,构建的随机参数负二项模型有更好的拟合优度,且能更合理地反映各因素对事故的作用效果;将随...