Stability Criteria for Articulated Railway Vehicles Possessing Perfect Steering

The general form of the equations o f motion o f multi-body articulated railway vehicles are used to establish the conditions which the elastic stiffness matrix, which describes the nature and configuration o f the suspension elements connecting the various bodies, must satisfy in order to achieve both perfect steering on circular curves and dynamic stability. The resulting criteria are then used to discuss the properties of various multi-axle configurations which are either typical of current practice or possibilities for future designs.     

车辆稳定性控制在奔驰商用车中的应用

目前,主动安全技术作为汽车安全的重要手段之一,已经得到汽车制造厂商的普遍重视。与此同时,车辆局域网的普遍采用,使得早期相对独立的各种功能,通过计算机网络重新组合起来,相互协同,组成一个新的更强的系统。其中的车辆稳定控制系统就是这一组合系统的典型范例。它将发动机的     

商用车市场调整过后展新局——中国商用车市场2006年回眸与2007年展望

回眸2006年,“十一五”开局之年,中国汽车市场的表现的确不同凡响,车市实际增长明显高于预期,商用车市场缓步走出调整期。展望2007年,党的十七大即将召开,宏观经济更加稳健,中国车市前景看好,但商家鏖战亦急,市场博弈也愈难。2006年车市:果然就旺了起来2006年是中国旧历的狗年,     

Static and Dynamic Stability of Unsymmetric Two-Axle Railway Vehicles Possessing Perfect Steering

For railway vehicles having coned wheels mounted on solid axles, there is a conflict between the stability of lateral deviations from the motion along the track and the ability to steer round curves. A general theory is developed for the two-axle vehicle in which there is a lack of symmetry, fore-and-aft, both of the interwheelset structure and of the equivalent conicities of the wheelsets. It is shown that whilst parameters can be selected which provide static and dynamic stability and perfect steering for both directions of motion, there is a lightly damped mode of oscillation for any practical configuration and the significance of this is discussed.     

商用车资讯

福田·潍柴达成战略合作5月10日,潍柴与福田在长沙签订福田瑞沃·潍柴动力战略合作协议,约定整合资源、集成知识、链合创新,利用瑞沃中重卡ADX产品的推广,实现共赢。     

Roll Plane Analysis of Articulated Tank Vehicles During Steady Turning

SUMMARY

The rollover immunity levels of articulated tank vehicles with partial loads are investigated. A static roll plane model of the articulated vehicle employing partially filled cylindrical tank is developed. The vertical and lateral translation of the liquid cargo due to vehicle roll angle and lateral acceleration, encountered during steady turning, are evaluated. The roll moments arising from vertical and lateral translation of the liquid cargo are determined and incorporated in the roll plane model of the vehicle. The adverse influence of the unique interactions of the liquid within the tank vehicle, on the rollover limit of the articulated vehicle is demonstrated. The influence of compartmenting of the tank on the steady turning roll response of the vehicle is analyzed, and an optimal order of unloading the compartmented tank is discussed.     

Roll Plane Analysis of Articulated Tank Vehicles During Steady Turning

The rollover immunity levels of articulated tank vehicles with partial loads are investigated. A static roll plane model of the articulated vehicle employing partially filled cylindrical tank is developed. The vertical and lateral translation of the liquid cargo due to vehicle roll angle and lateral acceleration, encountered during steady turning, are evaluated. The roll moments arising from vertical and lateral translation of the liquid cargo are determined and incorporated in the roll plane model of the vehicle. The adverse influence of the unique interactions of the liquid within the tank vehicle, on the rollover limit of the articulated vehicle is demonstrated. The influence of compartmenting of the tank on the steady turning roll response of the vehicle is analyzed, and an optimal order of unloading the compartmented tank is discussed.     

Roll Dynamics of Commercial Vehicles

An analytical model is developed here for studying the roll dynamics of commercial vehicles. Large displacements and rotations are accounted for in this nonlinear model so that it can be used for the study of roll dynamics well beyond the limits of wheel lift-off. The model is used to illustrate some of the dynamic phenomena in vehicle rollover, especially the interactive coupling between the roll and the vertical modes of motion. The influence of suspension backlash on rollover resistance is demonstrated, and the phenomenon of roll motion resonance is illustrated to suggest new means for evaluating vehicle rollover sensitivity.     

7月,商用汽车历史性发展机遇呈现

2001年7月,一个不平凡的月份:从月初纪念中国共产党成立80周年,紧接着国家经贸委向社会公布了包括汽车、机械、冶金等1 3个行业的"十五"规划;7月4日又传来了中国加入WTO实质性谈判已经完成的消息;而7月1 3日晚北京赢得了2008年奥运会的主办权,又将中国与世界之间的距离拉近.在冷静思考之后,笔者深切地感受到我国商用汽车行业发展的历史性机遇已经呈现,相信借着良好的政策导向和社会需求拉动,我国的商用汽车在最近的几年中将会有突飞猛进的发展.     

Lateral Control of Commercial Heavy Vehicles

Two nonlinear lateral control algorithms are designed for a tractor-semitrailer type commercial heavy vehicle. The baseline steering control algorithm is designed utilizing input-output linearization. To enhance the lateral stability and furthermore reduce tracking errors of the trailer, braking forces are independently controlled on the inner and outer wheels of the trailer. The coordinated steering and braking control algorithm is designed based on the multivariable backstepping technique. Simulations conducted using the complex model show that the trailer yaw errors under coordinated steering and independent braking force control are much smaller than those without independent braking force control.     

商用车除霜性能提升方法研究

论述了影响汽车前风窗玻璃除霜系统性能的两个主要因素及具体要求;通过2个商用车的实际案例,分别研究如何通过优化除霜风道和提升发动机水温,从而改进前风窗玻璃表面风速分布和出风温度,最终实现除霜性能提升。     

Lateral Control of Commercial Heavy Vehicles

Two nonlinear lateral control algorithms are designed for a tractor-semitrailer type commercial heavy vehicle. The baseline steering control algorithm is designed utilizing input-output linearization. To enhance the lateral stability and furthermore reduce tracking errors of the trailer, braking forces are independently controlled on the inner and outer wheels of the trailer. The coordinated steering and braking control algorithm is designed based on the multivariable backstepping technique. Simulations conducted using the complex model show that the trailer yaw errors under coordinated steering and independent braking force control are much smaller than those without independent braking force control.     

采埃孚商用车独立悬架新技术

独立悬架系统(IFS)具有安装空间小、自质量轻、同一桥的2个车轮不再相互影响等优势.自20世纪90年代以来,随着车速的提高以及乘客对舒适性要求的提高,独立前悬架系统已经成为欧洲长途客车的标准配置,北美的部分长途客车也开始配置独立悬架系统.如今,随着我国道路条件的改善、乘客对舒适性要求的提高,国内一些客车主机厂也纷纷开始了独立悬架系统的开发应用.     

商用汽车驾驶员座椅的静态特性

许多长期从事坐姿工作的人,一般都患有腰部疾病,即使是健康的人,长时间保持一种坐姿,也会感到背、腰、臀以及大腿疲劳,甚至疼痛.其主要原因是重力作用于人体组织,局部血液流动不畅,各种代谢物质积累,由此引起各种不适感.分散重力、避免局部受力过大或者不断调换坐姿,以使各部分组织轮换休息,就可消除或减少上述的不适感.     

Influence of Liquid Load Shift on the Dynamic Response of Articulated Tank Vehicles

The influence of the lateral load shift on the dynamic response characteristics of an articulated tank vehicle is investigated assuming inviscid fluid flow conditions. A quasi-dynamic roll plane model of a partially filled cleanbore tank of circular cross-section is developed and integrated to a three-dimensional model of the articulated vehicle, assuming constant forward speed. The destabilizing effects of liquid load shift are studied by comparing the directional dynamics of the partially filled tank vehicle to that of an equivalent rigid cargo vehicle subject to steady steer input. Dynamic response characteristics demonstrate that the stability of a partially filled tank vehicle is adversely affected by the Liquid load shift The distribution of cornering forces caused by the liquid load shift yield considerable deviation of the path followed by the liquid tank vehicle. The influence of the vehicle speed on the dynamics of the liquid tank vehicle is also investigated for variations in the fill levels and fluid density.