Active Steering of a Rail Vehicle with Two-Axle Bogies Based on Wheelset Motion

Summary This paper deals with a basic study on the actively steered rail vehicle with two-axle bogie trucks, which employs a control law based on the self-steering ability of wheelset. However, this control law not only helps the steering performance, but also tends to lower the running stability. Two methods are proposed to improve the stability. The first method is to add a feedback of wheelset lateral velocity, the second one is to give some time lag to the control force, and both are proved to be affective. Here, the latter is more practical method and the delay of control due to the time lag does not deteriorate the steering performance.     

Active Steering of a Rail Vehicle with Two-Axle Bogies Based on Wheelset Motion

Summary This paper deals with a basic study on the actively steered rail vehicle with two-axle bogie trucks, which employs a control law based on the self-steering ability of wheelset. However, this control law not only helps the steering performance, but also tends to lower the running stability. Two methods are proposed to improve the stability. The first method is to add a feedback of wheelset lateral velocity, the second one is to give some time lag to the control force, and both are proved to be affective. Here, the latter is more practical method and the delay of control due to the time lag does not deteriorate the steering performance.     

Validation of a MATLAB Railway Vehicle Simulation Using a Scale Roller Rig

SUMMARY

A 1/5 scale roller rig has been constructed for use in analysing the dynamic behaviour of railway vehicles. The roller rig includes a servo hydraulic system to allow a realistic input of track irregularities at the rollers and instrumentation is fitted to allow measurement of the position and acceleration of the bodies. This paper reports on the first stage in validating the behaviour of the roller rig using a relatively simple, linear computer model constructed in MATLAB. Initial results show good correlation between the behaviour seen on the roller rig and that predicted by the model.     

Parametric Excitation of a Single Railway Wheelset

This paper presents the results of analytical, numerical and experimental investigations of a single railway wheelset. Periodic parametric excitation is added to one of the simplest linear mechanical models. This extended model describes, for example, the geometric deviations often experienced on roller rigs. Above a certain critical speed, the stationary running of the wheelset loses its stability. To verify the analytical and numerical results for the critical speed, experiments were carried out on a simple roller rig having a large ratio of the radii of the roller and the railway wheel.     

Flange Force Effects on the Motion of a Train Wheelset

The motion of a train wheelset is investigated using Hopf bifurcation theory. The method takes full account of the nonlinear effects of the flange-rail contact forces which are incorporated in the model; The numerical solution is obtained over a wide range of forward speeds by transforming the bifurcation problem into a regular nonlinear boundary value problem, which is solved by standard methods. This solution is shown to be orbitally, asymptotically stable. The algorithm supplies complete information on the lateral and yaw motions and on the period of oscillation, even for very high forward speeds.     

Parametric Excitation of a Single Railway Wheelset

This paper presents the results of analytical, numerical and experimental investigations of a single railway wheelset. Periodic parametric excitation is added to one of the simplest linear mechanical models. This extended model describes, for example, the geometric deviations often experienced on roller rigs. Above a certain critical speed, the stationary running of the wheelset loses its stability. To verify the analytical and numerical results for the critical speed, experiments were carried out on a simple roller rig having a large ratio of the radii of the roller and the railway wheel.     

儿童约束系统翻转试验台设计

为克服现有技术的不足而提供一种通用性强、操作简单、整体轻便、移动方便、功能完善、安全性高、故障率低的儿童约束系统翻转试验台。本文首先对儿童约束系统翻转试验台的设计要求进行了分析,其次对该试验台的机械结构与电控系统进行了设计,最后通过实际试验,验证了该试验台设计的正确性及其工作的可靠性;并总结出了此试验台的创新点,对同类型试验台的设计具有很好的参考价值。     

主题导引下压路机造型设计方法研究

探讨了一种适合压路机的造型方法,通过实例及发展趋势分析得出设计主题,应用感性工学原理及实例推导将产品概念具象化,构建了压路机的造型库。此方法可以方便、快速、高效地对产品的造型进行设计．缩短了产品设计周期,为产品迅速占领市场提供了基础。     

A Note on the Lyapunov Stability Analysis of a Linear Railway Wheelset

In this paper a Lyapunov function is generated for the linearized equations governing a steel wheelset on steel rails. Thus the authors attack the asymmetric problem, and successfully apply Ingwerson's method for constructing Lyapunov functions. The stability criteria applied to this function yield a closed-form expression for the critical forward speed of the wheelset. Thus the authors retain the advantage of Lyapunov's direct method by obtaining an explicit solution for the critical speed. And, although this linearized result has been obtained by other methods, the result is provocative because it suggests that a similar attack on the intractable nonlinear problem (currently being mounted by the authors) may indeed bear fruit.     

基于机群智能化施工要求的智能压路机设计

通过分析机群智能化施工对压路机智能化的要求,开发出了可实现无级变频变幅的激振器。在此基础上设计了能自动检测与控制自身技术状态、运行参数、作业质量,并可与机群智能化施工控制中心及其他相关机械进行无线通讯联系的智能压路机。     

国外振动压路机设计的发展趋势

简要介绍了一些国外振动压路机在振动技术、自动化、智能化、人性化以及满意性设计、绿色环保设计等方面的思路和发展趋势。     

滩涂修井机机动性能设计计算

详细论述了滩涂修井机的机动性能指标的计算过程,为最大限度发挥滩涂机的良好越野性能提供计算依据.     

新型两轮压路机设计方案

介绍了一种新型双钢轮压路机的设计思想、传动方案及主参数设计，并认为这是一个性能较好，使用可靠，成本较低，用户易接受的经济机型。     

智能压路机行走控制系统设计

在分析智能压路机行走控制系统控制要求的基础上，采用闭环控制理论和机电液一体化技术，进行了智能压路机行走控制系统的软、硬件设计，构建了基于CAN总线的数字控制系统，实现了要求的控制功能。通过现场调试证明了智能压路机行走控制系统软、硬件系统设计的正确性以及良好的协调性，达到了预期的控制目标。     

Design of an Active Unilateral Brake Control System for Five-Axle Tractor-Semitrailer Based on Sensitivity Analysis

SUMMARY

This paper presents the results of a parametric sensitivity analysis of a five-axle tractor-semitrailer vehicle combination using 3-DOF linear yaw/plane model. The first order logarithmic sensitivity functions are derived with respect to several vehicle design parameters. For stabilization of the vehicle's directional behaviour a fairly new control concept called “Active Unilateral Braking Control (AUBC)” acting on the tractor rear wheel's in order to produce a stabilizing yaw torque is investigated. The AUBC system improves not only the directional stability, but also affects the roll dynamics of the vehicle. The sensitivity of the controlled vehicle system with linear quadratic controller (LQR) is also examined, a robust controller design procedure is proposed as a result of the sensitivity analysis. The robustness of this controller in the presence of both internal (including parametric uncertainties, non-linear dynamics) and external disturbances (such as road irregularities and side wind) allows its implementation with confidence with a non-linear vehicle model. The applicability of this control system to a non-linear vehicle model is tested using a 34 DOF, non-linear vehicle model of the tractor-semitrailer combination.