Vehicle Modelling Aspects for an Embedded Real-Time Application

In this paper we present results obtained for a driving advice system developed, within the framework of the Prometheus program. The main results concern the vehicle modelling, which is required for the evaluation of the vehicle's dynamic behaviour in real-time, and the safety parameters considered and developed in order to evaluate the vehicle's safety state. The demonstrator is briefly presented, together with the results.     

Modelling and Control of an Automated Vehicle

We present a vehicle model that includes the vehicle dynamics and a vehicle tire model. The model developed is then used for conducting steering analysis of an automated vehicle. We test the developed model on a step lane change maneuver and propose a model-reference based controller for remote control of a vehicle. Stability analysis of the closed-loop system using die Lyapunov approach is included.     

基于WinCE嵌入式车辆信息系统的应用

结合目前车辆信息系统的现状,研究基于WinCE系统进行开发的信息平台系统。系统集成了车辆故障诊断专家系统,提高了车辆的保障能力和通信的有效性、安全性。     

A Review of Modelling Methods for Railway Vehicle Suspension Components

The dynamic behaviour of railway vehicles has been the subject of study for over a century but the advances in computing technology in the last few years have led to a very rapid development in the use of numerical techniques for solving railway vehicle dynamics problems. As these techniques have developed, and have been applied to ever more complex problems, the modelling of the vehicle components has increased in importance. Mathematical models of railway vehicles may now include components such as swing links, air-springs, trailing arm suspensions, load sensitive friction dampers, rubber bushes with hysteresis etc, all of which require sophisticated modelling techniques to produce accurate results. This paper looks at the developments that have taken place in this area, the background to the need for sophisticated models, the improvements in accuracy that can result and some of the difficulties in applying these techniques to the modelling of real situations.     

越野车辆典型地形通过性建模与仿真

以某型8×8越野车辆为研究对象,对车辆的轮胎、悬架等关键模型进行了分析,得出了轮胎内压与轮胎刚度基本成线性关系的结论,建立了轮胎的粘弹性有限元模型;以多体动力学理论建立了车辆的8自由度动力学模型.对比分析了微分-代数方程组解法的优缺点,采用Gear算法实现了方程组的解算.实车试验与仿真结果对比表明,所建立的典型地形通过性仿真系统与实车测试有较好的吻合性.     

A Review of Modelling Methods for Railway Vehicle Suspension Components

SUMMARY

The dynamic behaviour of railway vehicles has been the subject of study for over a century but the advances in computing technology in the last few years have led to a very rapid development in the use of numerical techniques for solving railway vehicle dynamics problems. As these techniques have developed, and have been applied to ever more complex problems, the modelling of the vehicle components has increased in importance. Mathematical models of railway vehicles may now include components such as swing links, air-springs, trailing arm suspensions, load sensitive friction dampers, rubber bushes with hysteresis etc, all of which require sophisticated modelling techniques to produce accurate results. This paper looks at the developments that have taken place in this area, the background to the need for sophisticated models, the improvements in accuracy that can result and some of the difficulties in applying these techniques to the modelling of real situations.     

运行速度和发动机油耗预测模拟技术研究

描述一种根据九五国家重点科技攻关"公路投资综合效益分析系统的研究"项目研究成果,开发的汽车运行速度和主要经济指标———发动机油耗的预测和模拟技术。本项技术主要是通过改变道路的几何条件、路面状况、交通量、交通组成、车辆特征、车辆载重和环境等因素,预测和模拟上述任一或组合因素的变化对车辆运行速度和油耗的影响。模拟结果将为进一步研究道路纵断面和平曲线的最佳组合、道路的改建条件和路面大、中修养护时机的确定提供决策和分析的数据基础。     

基于AUTOSAR的汽车电子控制系统嵌入式软件开发

阐述汽车开放式系统架构AUTOSAR的体系结构,基于AUTOSAR的嵌入式软件开发流程以及符合AUTOSAR嵌入式代码的开发成果;介绍应用AUTOSAR标准开发汽车电子控制单元软件的优点,以及对我国汽车行业研发该项技术的建议。     

Simulation Tools,Modelling and Identification,for an Automotive Shock Absorber in the Context of Vehicle Dynamics

For purpose of simulation of vehicle dynamics, a physical model of an automotive shock absorber has been developed and implemented in several software packages for multibody simulations. In the present paper, the damper model structure is shortly elaborated together with some measurement and estimation techniques to retrieve the model parameters, possibly from dynamometer measurements only. These techniques are illustrated on a shock absorber normally used on the front suspension of a BMW series 7.     

Simulation Tools, Modelling and Identification, for an Automotive Shock Absorber in the Context of Vehicle Dynamics

For purpose of simulation of vehicle dynamics, a physical model of an automotive shock absorber has been developed and implemented in several software packages for multibody simulations. In the present paper, the damper model structure is shortly elaborated together with some measurement and estimation techniques to retrieve the model parameters, possibly from dynamometer measurements only. These techniques are illustrated on a shock absorber normally used on the front suspension of a BMW series 7.     

Real-Time Longitudinal Location Estimation of Vehicle Center of Gravity

The longitudinal location of a vehicle’s center of gravity (CG) is used as an important parameter for vehicle safety control systems, and can change considerably according to various driving conditions. Accordingly, for the better performance of vehicle safety control systems, it is essential to obtain the accurate CG location. However, it is generally difficult to acquire the value of this parameter directly through sensors due to cost reasons. In this study, a practical algorithm for estimating vehicle’s longitudinal CG location in real time is proposed. This algorithm is derived based only on longitudinal motion of the vehicle, excluding excessive lateral, yaw and roll movements of the vehicle. Moreover, the proposed algorithm has main differences from previous studies in that it does not require information such as vehicle mass, vehicle moments of inertia, road grade or tire-road surface friction, which are difficult to acquire. In the proposed algorithm, the relationship between the ratio of rear-to-front tire longitudinal force and the corresponding wheel slips are used to determine the CG location. To demonstrate a practical use of the proposed algorithm, the ideal brake force distribution is tested. The proposed CG estimation algorithm and its practical use are verified via simulations and experiments using a test vehicle equipped with electro-mechanical brakes in the rear wheels. It is shown that the estimated CG locations are close to the actual ones, and that the deceleration can be maximized by the ideal brake force distribution.     

车辆实时监控系统中车载单元的设计与实现

车辆实时位置的确定和定位及状态信息的无线数据传输是车辆监控系统中的关键技术，其中包括GPS技术、GIS技术、无线数据通讯技术、信息融合技术等多种现代科技手段。为银行运钞车开发的车辆监控系统利用了Motorola 800MHz集群智慧网，自行开发了专用调制解调器，从而实现了GPS定位信息和控制信息的实时传输；车载定位单元采用惯性技术，可以有效克服个别地段GPS无法正常定位的缺陷；实施节能方案，可有效保障车载单元及车辆的正常运行。     

Modelling of Driver/Vehicle Directional Control System

Different driver models and driver/vehicle/road closed-loop directional control systems are reviewed and compared. Evaluation methods of vehicle handling quality based on closed-loop system dynamics, stability of the closed-loop system, and optimization of vehicle design are discussed.     

Modelling of Driver/Vehicle Directional Control System

Abstract

Different driver models and driver/vehicle/road closed-loop directional control systems are reviewed and compared. Evaluation methods of vehicle handling quality based on closed-loop system dynamics, stability of the closed-loop system, and optimization of vehicle design are discussed.     

车联网埋点数据测试的问题研究

车联网作为物联网在汽车领域的一个重要应用,在智慧运输、智能交通建设等方面发挥着至关重要的作用,车联网用户行为数据的采集,是用户行为分析中一个非常重要的环节.而"埋点"是数据采集(尤其是用户行为数据采集)的常用方法.埋点数据的准确性直接影响了车企对用户行为数据收集的准确率,测试数据的准确性变得尤为重要,本文着重从车联网的...     

纯电动汽车嵌入式控制系统的开发实践

纯电动汽车的控制系统任务多,如前进、倒车、制动、制动能量回收等,而且因汽车的安全性直接关系到乘坐人员的生命安全,所以对实时性和稳定性要求非常高。根据纯电动汽车控制系统的特点和DSP2407内部的丰富资源,如AD模块、CAN总线、看门狗等和实时操作系统UC/OS-Ⅱ出色的稳定性,本文开发出基于DSP2407和实时操作系统UC/OS-Ⅱ的纯电动汽车多任务控制系统。     

Railway Vehicle Modelling by the Constraint Equation Method*

A method for the dynamic analysis of railway vehicles is proposed. The method is based on both the using of constraint equations, and on the building of the mathematical model by means of the initial data.

The calculation models are nonlinear, due both to the connecting elements, and to the wheel-rail contact modelling. Solving of differential equations is achieved by time step integration. The method has been applied to the analysis of a freight wagon and a train unit.     

整车模态分析中焊点模拟方法的研究

针对整车有限元模态分析中,采用刚性梁单元模拟焊点时刚度无法控制和严重依赖网格的弊端,提出采用弹塑性梁单元模拟焊点的方法.以某轻型客车为例,建立整车有限元模型,分别采用上述两种单元模拟焊点进行模态分析.与试验结果的对比表明,整车模态分析中采用弹塑性梁单元模拟焊点的方法更接近试验结果,即更为准确、有效.