基于主动制动的半挂汽车列车横摆稳定性控制

为研究半挂汽车列车在高速大转向等极限操作工况下的横摆稳定性控制问题,建立了14自由度的半挂汽车列车非线性仿真模型;提出了牵引车与半挂车独立直接横摆力矩控制的横摆稳定性控制方案,通过牵引车和半挂车车轮的合理选择和主动制动实现横摆控制;以跟踪参考模型的稳态横摆响应为目标,设计了PI横摆稳定性控制器,对牵引车和半挂车分别设计了目标制动车轮的选择决策规则。单移线操作仿真结果表明,基于主动制动的横摆力矩控制可有效改善极限工况下半挂汽车列车的横摆稳定性,牵引车与半挂车进行独立横摆控制可以减小制动车轮选择决策的复杂性,而获得较好的控制效果。     

半挂车制动反应时间影响因素分析

分析了影响半挂车制动反应时间的诸多因素,为缩短半挂车制动反应时间以及牵引车和半挂车在制动反应时间上的合理匹配提供了理论参考.     

关于影响挂车自动制动响应时间的简单探讨

国内牵引车和挂车采用气压制动系统,其系统压力为0.85MPa,挂车在常规制动、紧急状况下的自动制动都可以通过牵引车来控制。挂车制动气源来自牵引车驻车回路,挂车与牵引车是通过两条管路进行连接的,其中红色管路为供能管路常有气,黄色管路为控制管路控制着挂车的制动和紧急状况下的自动制动。挂车分为半挂车和全挂车,本文讨论的是半挂车,对应的牵引车为半挂牵引车。     

基于辅助制动长大下坡路段鼓式制动器温升预测模型

建立辅助制动条件下长大下坡路段刹车鼓温度预测模型,为避险车道的设置提供理论依据。以国道108线青海省境内翻越日月山段长大下坡为研究对象,利用Racelogic VBOX iii设备,采集16组东风天龙半挂牵引车行车速度数据,通过非线性回归分析方法,建立辅助制动条件下刹车鼓温度与坡度、坡长、速度和初始温度的预测模型。结果表明,在辅助制动条件下,大货车刹车鼓温度不仅与坡度、坡长和初始温度有关,而且与车速也有很大关系,同时,与非辅助制动条件相比,辅助制动条件下的刹车鼓温度梯度(单位坡长制动鼓的温度变化)约减小24.7%。     

半挂车制动系

汽车半挂车的制动系是安全行驶的重要保证。当前国内外汽车半挂车制动传动机构大多数与主车(牵引车)制动传动机构相同,这样既有利于动力源的使用,又可简化结构,方便维修。目前国产载货汽车经改型为汽车半挂车的制动系统一般有如下情况:一、液压制动系液压制动系有简单制动传动机构和真空液压制动传动机构,即气压液压复合制动传动机构两种。以交通SH142型载货汽车经改制为汽车半挂车的制动系为例,其制动传动     

半挂汽车制动性能台试与路试检验的比较分析

<正>半挂汽车是公路货运的主要运输车型,它装载量大,运输效率高,经济性好。半挂汽车由半挂牵引车和半挂车组合而成,因车身长、车轴多,牵引车和挂车组合又不固定,常会将某牵引车和几辆半挂车组成多辆半挂列车,用甩挂方式提高运输效率。这种随时随地就能组合的半挂汽车的制动性能,能否确保安全行车是车辆检测的新课题。即使牵引车和挂车各自的制动性能都良好,但新组合的半挂汽车制动性能也未必都能符合安全行驶要求,这在一些半挂汽车     

基于线性变参数实时简化模型的重型半挂车稳定性控制策略

为实现重型半挂车各工况稳定性精准最优控制,提出了基于线性变参数实时简化模型的重型半挂车稳定性控制策略。该控制策略基于制动系统,采用分层控制方式,运用线性二次型调节器(LQR)方法,选择多个车辆状态为反馈状态,以实现重型半挂车横摆、折叠和侧倾稳定性综合控制;应用遗传粒子群算法,设计综合提高横摆、折叠和侧倾稳定性的优化目标函数,优化控制策略权重系数,以实现重型半挂车各工况稳定性最优控制;最后搭建硬件在环试验台并进行了台架试验。结果表明:采用所提出的控制策略后,牵引车质心侧偏角、牵引车横摆角速度、挂车质心侧偏角和挂车横摆角速度最大值分别改善了38.6%、13.8%、15.8%、8.4%,铰接角最大值改善了5.1%,牵引车侧向加速度、牵引车侧倾角、挂车侧向加速度、挂车侧倾角最大值分别改善了10.4%、15.4%、10.8%、17.7%,表明所设计的控制策略综合提高了重型半挂车普通工况的横摆、折叠和侧倾稳定性,并且实现了极限工况侧翻精准控制,从而避免重型半挂车侧翻。     

紧急继动阀在制动系统中的应用

紧急继动阀是国内近期在汽车制动的驱动装置内发展的新气动元件。它的基本功能对比于目前传统结构的继动阀更为健全,而性能亦更能满足各机动车辆的使用要求,灵敏度高(轻微制动反应快)。把它装置在挂车(半挂车)制动系统中,可能使其制动方式实现双管路充气制动,且可取代目前各类挂车(半挂车),单、双管路制动方式的驱动装置中挂车制动阀(装于牵引车)、挂车分     

半挂汽车列车路径跟随模糊控制联合仿真

应用Truck Sim建立了半挂汽车列车非线性整车模型,并建立了简化的四自由度线性参考模型,以牵引车和半挂车的路径偏差和偏差变化率为控制变量设计了模糊控制器,并设计了差动制动控制器对车轮施加制动力矩,然后利用MATLAB/Simulink和Truck Sim软件进行了联合仿真。结果表明,所提出的方法提高了半挂车对牵引车的跟随能力,可以有效地避免甩尾、折叠等危险事故的发生。     

汽车列车电控制动系统制动力分配的控制算法

为汽车列车提出了一种基于滑移率的电控制动系统制动力分配算法,即根据不同情况,使牵引车后轮和半挂车车轮的目标滑移率随牵引车前轮滑移率而变化.运用Matlab/Simulink和Trucksim软件进行列车在高附着和低附着路面上行驶的联合仿真,结果表明该算法能缩短汽车列车的制动距离,提高了制动稳定性.     

基于整车建模的半挂牵引车有限元分析

在调研国内外相关研究的基础上,对某半挂牵引车整车结构进行了建模,并对该牵引车进行了静态电测试验,为有限元分析提供实践依据,同时验证了有限元模型的正确性。利用已验证的有限元模型,分析了该牵引车在弯曲工况、扭转工况、紧急制动工况和紧急转弯工况下的应力分布和变形情况,同时对该牵引车整车结构进行了模态分析。     

牵引车、半挂车ABS道路试验及计算方法

ABS试验作为强制实施项目，受到汽车生产企业和检测部门的关注，牵引车、半挂车ABS试验往往连接在一起进行，与其它的机动车试验相比具有一定的特殊性，尤其是计算方法有所不同。详细介绍了半挂车空载、半挂车满载、牵引车满载工况的试验和计算方法，并以实例进行了说明。     

High-speed optimal steering of a tractor–semitrailer

A high-speed optimal trailer steering controller for a tractor–semitrailer is discussed. A linear model of a tractor–semitrailer with steered trailer axles is described, and an optimal trailer steering controller is introduced. A path-following controller is derived to minimise the path-tracking error in steady-state manoeuvres using active trailer steering. A roll stability controller is introduced by adding the lateral acceleration of trailer centre of gravity as another objective in the steering controller, so as to improve roll stability in transient manoeuvres. A strategy to switch between these two control modes is demonstrated. Simulation results show that the steering controller can ensure good path tracking of articulated vehicles in steady-state manoeuvres and improve roll stability significantly in transient manoeuvres, while maintaining the path-tracking deviation within an acceptable range. Tests with an experimental tractor–semitrailer equipped with a high-bandwidth active steering system validate the controller design and simulation results. The roll stability controller reduces the measured rearward amplification by 27%.     

中间位置转向试验与半挂牵引车操纵稳定性

根据半挂牵引车的特点，引入并修改了国外广泛应用的中间位置转向操纵稳定性试验方法，介绍了对试验结果的评价方法，并结合某国产牵引车和Scania360型牵引车进行了试验验证。通过试验发现，国产牵引车在路感、转向响应等方面都需进行改进；该试验方法在半挂牵引车操纵稳定性试验中应用是可行的。     

半挂汽车列车高速公路弯道下坡路段运行安全研究（双语出版）

为提升半挂汽车列车在高速公路弯道下坡路段的运行安全，采用TruckSim仿真软件，构建了车辆模型、道路模型和驾驶人动力学仿真模型；基于蒙特卡罗可靠性分析法，分别建立了半挂汽车列车发生侧滑失效、侧翻失效、折叠失效和系统失效的功能函数，并选取设计速度80 km·h^-1的高速公路为研究路段，通过进行大量车辆动力学仿真试验，对不同圆曲线半径、纵坡坡度、路面附着系数、车速和车辆总质量对半挂汽车列车的运行安全的影响进行了数值分析。研究结果表明：半挂汽车列车发生侧滑和侧翻的概率随着圆曲线半径的增加而显著降低，在一般最小半径400 m的情况下，半挂汽车列车发生侧滑失效和侧翻失效的概率趋近于0；随着下坡坡度的增加，半挂汽车列车发生侧滑失效和侧翻失效的概率基本呈线性增长趋势；车速对于半挂汽车列车运行安全的影响尤为显著，当车速均值由60 km·h^-1增加到90 km·h^-1时，发生侧滑失效和侧翻失效的概率分别增加了634倍和336倍；车辆总质量的增加对半挂汽车列车侧翻有显著影响；在路面附着系数较低的条件下，半挂汽车列车的主要事故形态为侧滑和折叠，在路面附着系数较高的情况下，半挂汽车列车的主要事故形态为侧翻。因此，在道路设计中，应避免极限最小半径与陡坡组合，严格限速和限载可确保半挂汽车列车的运行安全性能。     

Kinematic and dynamic analysis of a heavy truck with individual front suspension

The main focus of this work is on the characteristics of a commercial vehicle with individual front suspension (IFS). Both kinematic and dynamic properties of the vehicle are investigated through simulations and analytical expressions. Moreover, employing the model of the tractor semitrailer combination, the study presents the results of comparison between the trucks with IFS and rigid front axle with respect to comfort and handling. This is done by analysing the responses of the vehicles to different road and steering inputs. The obtained results show enhanced comfort and steering feeling for the truck with IFS.     

Frequency Response Analysis of Canadian Logging Trucks

SUMMARY

This paper examines the frequency responses often logging truck configurations currently operating in the interior of British Columbia in Canada. The work is an extension of a previous study conducted at the National Research Council (NRC) in 1990. The previous study presented an extensive analysts of the directional responses and frequency responses of four Canadian log-hauling truck configurations; a tractor/pole trailer, a tractor/triaxle trailer, a tractor/quadaxle trailer (with a single load), and a tractor/single-axle-jeep/pole trailer. In the current study, the frequency responses of these four configurations are compared with those of six more log-hauling truck configurations; a tractor/ tandem-axle-jeep/pole trailer, a doglogger, a double doglogger, a tractor/quadaxle trailer (with a dual load), a tractor/jeep/triaxle trailer, and a tractor/jeep/quadaxle trailer. The current study makes use of three models developed by NRC in the previous study, and a new model developed at NRC in cooperation with the University of Victoria.

The frequency response method has been applied in this study to predict the lateral acceleration at the centre of gravity of each articulated vehicle unit, and the rearward amplification ratio. The logging truck simulation results have been compared with corresponding results, obtained using UMTRI's simplified models, for three conventional highway vehicles; a tractor/semitrailer, a B-train, and an A-train. The comparison provides a useful indication of the differences between the behaviours of logging trucks and conventional highway trucks in their shared environment.     

Sideslip estimation for articulated heavy vehicles at the limits of adhesion*

Various active safety systems proposed for articulated heavy goods vehicles (HGVs) require an accurate estimate of vehicle sideslip angle. However in contrast to passenger cars, there has been minimal published research on sideslip estimation for articulated HGVs. State-of-the-art observers, which rely on linear vehicle models, perform poorly when manoeuvring near the limits of tyre adhesion. This paper investigates three nonlinear Kalman filters (KFs) for estimating the tractor sideslip angle of a tractor–semitrailer. These are compared to the current state-of-the-art, through computer simulations and vehicle test data. An unscented KF using a 5 degrees-of-freedom single-track vehicle model with linear adaptive tyres is found to substantially outperform the state-of-the-art linear KF across a range of test manoeuvres on different surfaces, both at constant speed and during emergency braking. Robustness of the observer to parameter uncertainty is also demonstrated.     

A Nonlinear Analysis of the Generic Types of Loss of Stability of the Steady State Motion of a Tractor-Semitrailer*

All different types of loss of stability which occur generically for a tractor semitrailer vehicle are studied when varying two parameters namely the speed V of the vehicle and the position d of the center of mass of the trailer. For a fixed value of d and varying V it turns out that only two cases either a divergence or a Hopf bifurcation can occur typically. By means of a nonlinear analysis the post-bifurcation behavior for both cases is treated showing that it is critical in both cases. This latter result means that the system is an imperfection sensitive one for which the calculation only of the linear stability limit, does not have very much practical meaning, because small perturbations of the system (changes of parameters) can lead to a drastic reduction of the critical speed. Our paper furthermore indicates how a nonlinear investigation of stability problems in vehicle dynamics with no restriction to the number of degrees of freedom of the system can be done in a straight forward manner.