Modelling minimum-time manoeuvering with global optimisation of local receding horizon control

In this paper, we explore the notion that a human driver uses a receding horizon model predictive control (MPC) scheme for minimum-time manoeuvering. However, MPC is an inherently sub-optimal control scheme because not all future information is incorporated into its finite preview horizon. In many practical applications, this sub-optimality is tolerated as the solution is sufficiently close to optimal. However, it is known that professional drivers have the ability to learn driving circuits and exploit its features to minimise their global manoeuvering time. In this paper, we will model their process with a cascaded optimisation structure. Therein, the inner-loop features a local MPC scheme tasked with finding the control inputs that achieve a blended objective of minimising time and maximising velocity in each preview horizon/distance. The outer loop of this cascaded structure computes the best set of weights for the two components of the local objectives in order to minimise the global manoeuvering time. The proposed cascaded optimisation and control approach is compared against a straight-forward fixed-cost time optimal MPC applied to minimum-time manoeuvering over two well-known race courses. The paper also includes an extended literature review and details of the computational formulation of the model approach.     

Physical processes in wheel–rail contact and its implications on vehicle–track interaction

Friction within the wheel–rail contact highly influences all aspects of vehicle–track interaction. Models describing this frictional behaviour are of high relevance, for example, for reliable predictions on drive train dynamics. It has been shown by experiments, that the friction at a certain position on rail is not describable by only one number for the coefficient of friction. Beside the contact conditions (existence of liquids, solid third bodies, etc.) the vehicle speed, normal loading and contact geometry are further influencing factors. State-of-the-art models are not able to account for this sufficiently. Thus, an Extended-Creep-Force-Model was developed taking into account effects from third body layers. This model is able to describe all considered effects. In this way, a significant improvement of the prediction quality with respect to all aspects of vehicle–track interaction is expected.     

考虑船体变形耦合作用的船舶推进系统建模与控制

提出考虑船体变形耦合作用的船舶推进系统仿真建模设计方法与系统框架,通过船体变形与动力装置振动烈度间的量化关系体现耦合作用对模型的影响;研究适合推进系统的先进控制技术,通过对简化后的船舶推进系统不确定模型进行仿真试验,结果表明,具有强自适应能力的神经网络控制和模糊控制技术能够满足系统对不确定性及时变非线性控制的要求,具有良好的控制效果。     

基于CRUISE软件的车辆性能分析与优化

本文以某款牵引列车的动力匹配为主线,分析该车的动力性能和燃油经济性能,建立这种牵引车的优化匹配框架,为其他牵引车的匹配提供参考。主要是对动力传动系统的调整,包括发动机、变速器、驱动桥主传动比,配合对用户实际用车环境的数据采集及分析,使用户的车辆在满足动力性能的情况下获得较为完美合理的经济性能。     

港口专用重型牵引车拖盘支腿自动化改造

为解决港口专用重型拖盘车支腿收入和伸出动作缓慢且浪费人力的问题,对港口专用重型拖盘车支腿进行自动化改造。分析多种方案并确定最佳方案。介绍根据方案实施改造的做法。改造取得客观的经济效益和社会效益。此项改造成果颇具推广价值。     

集装箱码头专用牵引车“一拖双挂”技术应用及推广

为提高设备运行效率,节约人力成本,一些集装箱码头开创了"一拖双挂"技术。介绍集装箱码头牵引车"一拖双挂"技术项目背景和发展情况。分析该项目节能原理,阐述车型选定、实施方案、技术创新点等。该项目取得良好节能效益、经济效益、社会效益。     

Vehicle dynamics control of an electric-all-wheel-drive hybrid electric vehicle using tyre force optimisation and allocation

ABSTRACT

Hybrid Electric Vehicles (HEV) offer improved fuel efficiency compared to conventional vehicles at the expense of adding complexity and at times, reduced total power. As a result, HEV generally lack the dynamic performance that customers enjoy. To address this issue, the paper presents a HEV with electric All-Wheel-Drive capabilities via the use of torque vectoring electric rear axle drive (TVeRAD) to power the rear axle. The addition of TVeRAD to a front wheel drive HEV improves the total power output. To improve the handling characteristics of the vehicle, the TVeRAD provides torque vectoring at the rear axle. A bond graph model of the drivetrain is developed and used in co-simulation with CarSim. The paper proposes a control system which utilises control allocation to optimise tyre forces. The proposed control system is tested in the simulation environment with a high fidelity CarSim vehicle model. Simulation results show the control system is able to maximise vehicle longitudinal performance while avoiding tyre saturation on low mu surfaces. More importantly, the control system is able to track the desired yaw moment request on a high speed double lane change manoeuvre through the use of the TVeRAD to improve the handling characteristic of the vehicle.     

普通半挂牵引车驾驶室舒适性评价

由于传统半挂牵引车驾驶室采用的是半悬浮被动悬置,减振效果不好,对于经常进行中长途运输的半挂牵引车司机而言,连续较长时间的驾驶会使司机暴露于机械性全身振动(WBV)之中。由于目前还没有确凿的证据证明半挂牵引车司机的腰痛等职业病与全身振动有直接关联,故为探索有关驾驶半挂牵引车的健康风险程度进行了试验验证。对同一辆试验车在不同路面、载荷和车速的多工况下进行了研究,并将试验结果与标准GB/T 13441.1-2007附录B中的健康指南警告区域进行了对比。研究表明,在当前的行驶条件下,我国半挂牵引车司机每天的连续驾驶时间最多不应超过5.5 h。     

Analysis of lateral tyre friction dynamics1

The tyre friction model is a key part of the overall multi-body tyre dynamics model. The LuGre dynamic tyre friction model is analytically linearised for pure cornering conditions. The linearised model parameters are conveniently expressed as functions of static curve slope parameters. The linearised lateral force and self-aligning torque submodels are described by equivalent mechanical systems. The linearised model and equivalent system parameters are analysed for different slip angle and wheel centre speed operating points. An example of the application of linearised tyre friction model to tyre vibration analysis is presented as well.     

Book reviews

THE SEVENTH AUSTRALIAN TRANSPORT RESEARCH FORUM, by K. W. Ogden.

AIRLINE PLANNING: CORPORATE, FINANCIAL AND MARKETING by Nawal K. Taneja. Lexington, Mass., Lexington Books, 1982. 207 pp. (£19.50)

SOLVING LOCAL GOVERNMENT PROBLEMS: PRACTICAL APPLICATIONS OF OPERATIONS RESEARCH IN CITIES AND REGIONS, by Charles E. Pinkus and Anne Dixson. George Allen and Unwin, London, 1981. (Hardback £20.00; paperback £8.95)

SCIENTIFIC MANAGEMENT OF TRANSPORT SYSTEMS, edited by N. K. Jaismal. Published by North‐Holland Publishing Company (U.S. $58.50)

TRANSPORTATION AND TRAFFIC ENGINEERING HANDBOOK (Second Edition), edited by W. S. Homburger, Englewood Cliffs, N.J., 1982. Prentice Hall, pp. 883.

ECONOMICS OF PUBLIC TRANSPORT, by C. A. Nash. Longman, London, pp. 194. (£6.95).