新一代机车控制柜功能测试台

描述了一种用于电力机车电子柜和微机柜进行系统级功能测试的试验设备,对其功能、系统组成和软硬件设计特点进行了说明.该测试台已完成样机试验,在测试精度和响应速度方面有很大提升.     

基于RFID技术的混凝土搅拌站车辆管理系统

混凝土搅拌站运输车大流量运输作业过程中,传统的人工管理计数、统计、调度、监控等环节的工作十分繁琐,且效率低下。针对人工管理模式的缺陷进行信息化管理模式的改进,将RFID(无线射频识别)技术与计算机软件技术相结合,对进出搅拌站的运输车辆实行无人值守的管理,克服了传统方法的弊端。设备安全耐用,使用方便,系统灵敏可靠,提高了工作效率和经济效益,具有很强的实用性。     

网联车辆并线预测与巡航控制的研究

为检测旁车道车辆驾驶员的并线意图,提升网联车辆巡航跟车的主动安全性,提出了一种基于NAR神经网络学习的迭代循环预测算法。NAR神经网络的训练样本由实际交通环境中的车辆并线数据获得,通过训练的网络预测未来一段时间内旁车的横向行驶轨迹,并根据划定的监控区域计算旁车的切入概率。同时,提出了一种考虑并线概率的跟车距离策略,并应用到网联车辆CACC系统中。结果表明,所提出的并线预测算法能精确计算出旁车的横向换道轨迹,所提出的跟车策略可提升车辆的跟车安全性。     

灰铸铁飞轮疲劳失效分析

大马力飞轮是商用车一款大马力发动机的零部件,其搭载大马力发动机为商用车提供动力总成。飞轮在工作期间,因经常与离合器摩擦,售后市场出现离合器打滑,起步困难、抖动较大等整车问题,拆解后发现,飞轮表面出现磨损不平、表面微裂纹为主要的失效形态的现象。     

Optimal roll control of an articulated vehicle: theory and model validation

This paper investigates optimal roll control of an experimental articulated vehicle. The test vehicle and the mathematical model used to design the control strategies are presented. The vehicle model is validated against experimental data from the test vehicle in passive configuration. The initial controller design, performed by Sampson (Sampson, D.J.M. and Cebon, D., 2003a, Achievable roll stability of heavy road vehicles. Proc. Instn. Mech. Engrs, Part D, J. Automobile Engineering, 217(4), 269–287), is reviewed and adapted for the experimental vehicle. The effect of not controlling all the axles on the vehicle is investigated and a variable vehicle speed controller is designed by interpolating between constant speed controllers. Substantial reduction in normalized load transfer is achieved for a range of manoeuvres, both in steady-state and transient conditions.     

Roll- and pitch-plane coupled hydro-pneumatic suspension

Passive fluidically coupled suspensions have been considered to offer a promising alternative solution to the challenging design of a vehicle suspension system. A theoretical foundation, however, has not been established for fluidically coupled suspension to facilitate its broad applications to various vehicles. The first part of this study investigates the fundamental issues related to feasibility and properties of the passive, full-vehicle interconnected, hydro-pneumatic suspension configurations using both analytical and simulation techniques. Layouts of various interconnected suspension configurations are illustrated based on two novel hydro-pneumatic suspension strut designs, both of which provide a compact design with a considerably large effective working area. A simplified measure, vehicle property index, is proposed to permit a preliminary evaluation of different interconnected suspension configurations using qualitative scaling of the bounce-, roll-, pitch- and warp-mode stiffness properties. Analytical formulations for the properties of unconnected and three selected X-coupled suspension configurations are derived, and simulation results are obtained to illustrate their relative stiffness and damping properties in the bounce, roll, pitch and warp modes. The superior design flexibility feature of the interconnected hydro-pneumatic suspension is also discussed through sensitivity analysis of a design parameter, namely the annular piston area of the strut. The results demonstrate that a full-vehicle interconnected hydro-pneumatic suspension could provide enhanced roll- and pitch-mode stiffness and damping, while retaining the soft bounce- and warp-mode properties. Such an interconnected suspension thus offers considerable potential in realising enhanced decoupling among the different suspension modes.     

Influence of polygonal wear of railway wheels on the wheel set axle stress

The coupled vehicle/track dynamic model with the flexible wheel set was developed to investigate the effects of polygonal wear on the dynamic stresses of the wheel set axle. In the model, the railway vehicle was modelled by the rigid multibody dynamics. The wheel set was established by the finite element method to analyse the high-frequency oscillation and dynamic stress of wheel set axle induced by the polygonal wear based on the modal stress recovery method. The slab track model was taken into account in which the rail was described by the Timoshenko beam and the three-dimensional solid finite element was employed to establish the concrete slab. Furthermore, the modal superposition method was adopted to calculate the dynamic response of the track. The wheel/rail normal forces and the tangent forces were, respectively, determined by the Hertz nonlinear contact theory and the Shen–Hedrick–Elkins model. Using the coupled vehicle/track dynamic model, the dynamic stresses of wheel set axle with consideration of the ideal polygonal wear and measured polygonal wear were investigated. The results show that the amplitude of wheel/rail normal forces and the dynamic stress of wheel set axle increase as the vehicle speeds rise. Moreover, the impact loads induced by the polygonal wear could excite the resonance of wheel set axle. In the resonance region, the amplitude of the dynamic stress for the wheel set axle would increase considerably comparing with the normal conditions.     

舰船智能化组合式电子互感器研究

随着舰船电力系统容量的不断增长,舰船额定电流和故障电流都成数量级增长,原有的互感器已逐渐不能满足应用的要求了,通过介绍新型船用电子互感器的一种类型-智能化组合式电子互感器,提出以Rogowski为电流互感元件并简要分析了Rogowski线圈的结构原理和数学模型,电压传感部分和电源部分设计方案,对信号集中处理电路模块作了详细的分析.该互感器集电流、电压、功率方向等电网运行参量的测量于一体,同时提供与继电保护设备以及远程控制计算机的CAN总线通信接口,符合未来舰船智能化监控系统改装的要求.     

Full vehicle simulation using thermomechanically coupled hybrid neural network shock absorber model

In the case of full vehicle models, the technique of multi-body simulation (MBS) is frequently used to study their highly non-linear dynamic behaviour. Many non-linearities in vehicle models are induced by force elements like springs, shock absorbers, bushings and tires. Commonly, spline functions are used to represent the force responses of these components. If the non-linear relationships are more complicated, the spline approximations are no more accurate. An alternative approach is based on empirical neural networks which are based on the mathematical approximation of measured data. It is well known that neural networks are able to represent and predict complex component responses accurately. The aim of this paper is to perform a dynamic full vehicle simulation using a thermomechanically coupled hybrid neural network shock absorber model. In this shock absorber model, the spline approach is combined with a temperature-dependent neural network. Based on a displacement-controlled excitation on a four post test rig in the ADAMS/Car MBS software, a rugged test track is simulated. In this way, the front and rear shock absorbers are dynamically loaded with comfort-relevant frequencies in the range of 0.75-30 Hz and velocity amplitudes up to 2 m/s. By the simulation, stability of the hybrid neural network model is demonstrated. Furthermore, the damping force, the vertical acceleration of the chassis and the required simulation times are compared. The standard spline approach is used as a reference.     

高速铁路电力远动技术的应用和思考

目前,电力远动技术在高速铁路中得到广泛的应用,并在功能上得以增强,对确保运输安全供电及快速抢修起到积极的作用。本文以郑西高速铁路电力远动系统为例,介绍其构成、功能及应用情况,并结合现场实际,对电力线路故障点判断提出建议。