混凝土搅拌运输车水平道路转向侧翻稳定性计算

根据国家特种车辆设计标准,选取混凝土搅拌运输车侧翻稳定性计算的各项参数,对水平路面不同转向和旋向车辆的侧翻稳定性进行计算,得到控制混凝土搅拌运输车转向侧翻的最高行驶车速,为规范二类通用底盘型混凝土搅拌运输车安全行驶车速提供了理论依据。     

混凝土搅拌运输车运营安全管理之研究

混凝土搅拌运输车今年以来发生多起行驶中侧翻事故，造成交通严重堵塞。通过对该车结构特点、运营使用特性研究以及稳定性影响因素的分析计算和试验检验，结果表明：该车重载与普通货车相比，有明显不同特性，行驶途中由于搅拌或搅动作业，对车辆行驶稳定性产生较大影响。分析结果为该车辆运行安全管理，提供了科学依据。     

混凝土搅拌运输车操纵稳定性测试分析与评价研究

随着JT/T 1178.1-2018《营运货车安全技术条件第1部分:载货汽车》的发布与实施,混凝土搅拌运输车需要进行操纵稳定性试验,主要包括蛇形试验、稳态回转试验以及抗侧翻试验。主要测量了车辆的瞬态行驶稳定性、不足转向度和抗侧翻稳定性,通过对不同车型混凝土搅拌运输车的试验数据进行对比,分析影响操纵稳定性的主要因素并提出解决方法。与此同时,对混凝土搅拌运输车的操纵稳定性试验的注意事项进行了归纳。     

乘用车双离合器式自动变速器坡路模式换挡规律标定的研究

通过理论计算和实车验证分析双离合器自动变速器车辆在坡路行驶时产生的换挡循环、换挡频繁、动力不足等问题。为获得更好的驾驶性,根据上坡模式的基本设定原则和零加速度点的计算方法,制定一种针对坡路模式的换挡规律,并进行实车试验。试验结果表明,在坡路上行驶时使用坡路模式换挡规律的车辆动力性明显增强,换挡次数明显减少,在保证经济性的情况下提高了车辆在坡路上的驾驶性。     

一种多轴车辆的测功试验台转向行驶模拟方法

本文中提出了一种适用于在测功试验台上进行的多轴车辆转向行驶模拟方法,提出了一种由行驶模型、转向模型和转向控制策略3部分组成的车辆模型。首先根据车辆的行驶情况,通过车辆转向控制策略和转向模型获得当前时刻的多轴车辆各轴转向角与车辆的转向状态。然后通过车辆行驶模型计算得到多轴车辆各轴当前时刻的运动状态。最后通过测功机对车辆各驱动轴进行加载,并采用电惯量模拟技术对系统不足的惯量进行补偿,使测功系统中各轴的运动状态跟随模型计算结果而变化,以实现在测功试验台上的多轴车辆转向行驶模拟。一辆多轴车辆在等速转向、加速转向、减速转向等行驶状态下进行仿真的结果,初步验证了该方法的可行性。     

人工神经网络在车辆行驶称重技术中的应用

车辆行驶称重技术是通过测量分析车辆轮胎与路面作用力,从而计算车辆的静态载荷和静态轴载等相关参数的车辆载荷检测技术。基于人工神经网络综合分析了影响轮胎作用力的各个因素的影响关系,通过自行研制的油管传感器式车辆行驶称重仪进行了相关试验验证,达到了预定的精度和实用要求。     

车辆自适应车道偏离识别算法研究

针对车辆在行驶时由于车道线检测方法单一,导致对直道线和弯道线检测效果不一致,从而影响车道偏离识别效果的问题,基于摄像头采集到的图像信息,提出了1种自适应车道偏离识别算法。该算法对车辆在直道行驶时采用偏离判断基准线法,而在弯道行驶时采用基于触线时间阈值法,分别对行驶状态进行车道偏离判断,该算法既保证了计算速度,又保证了结果的准确性。为了验证所提出方法的有效性,采用仿真的方法,使用车道偏离识别算法获取的数据,通过比例-积分-微分(PID)算法对车辆行驶状态进行控制,得到车辆在预期车道内的行驶状况,以此证明了所提出的车道偏离识别算法的有效性。     

基于超声波的高速公路防倒车作弊装置设计

高速公路无人值守自动发卡系统存在缺陷,作弊车辆有机会盗取通行卡。文中分析了现有设计的不足,针对取卡车辆倒车装置重复取卡的作弊方式,设计了一种基于2个超声波测距传感器的车辆行驶方向检测装置。该装置通过单片机判断传感器信号变化的时序检测车辆的行驶方向;通过继电器与串口接入发卡系统,对原有系统改动极小。试验结果显示该装置可有效检测车辆行驶方向,阻止倒车作弊行为。     

车辆行驶跑偏试验方法研究与分析

车辆保持直线行驶的能力是汽车行驶稳定性的一个重要评价项目,为测量车辆行驶跑偏量,国家颁布了相应法规,规定了相应的试验方法。文章详细介绍了车辆行驶跑偏试验方法,针对标准要求搭建检测系统并进行相关试验。由于标准要求定位精度过高,因此提出了一种简化的试验设备测试方法,通过试验结果比较,发现简化方法精度满足厘米级检测要求,适用于汽车制造商进行车辆跑偏检测工作,降低测试成本。     

智能驾驶小型电动车的设计

设计了一种智能引导和人工驾驶两用的小型电动汽车。该电动汽车利用超声波传感器和激光传感器作为障碍探测感知传感器,通过增量式旋转编码器测量车辆车速,采用PID算法实现车速调节控制。通过样车试验表明,所设计的小型电动汽车能够在特定区域沿墙行驶或沿预设地面黑线稳定的自主行驶,同时能够主动避障。     

Dynamics of Tracked Vehicles

This paper provides a brief review of the state-of-the-art of tracked vehicle dynamics, including mobility over soft terrain, ride dynamics over rough surfaces and manoeuvrability. It is found that considerable progress has been made in the development of analytical frameworks for evaluating and predicting tracked vehicle mobility over soft terrain, taking into account the characteristics of terrain response to normal and shear loading. Certain computer simulation models for tracked vehicle mobility have been gaining increasingly wide acceptance by industry and governmental agencies in product development and in procurement. It is also found that most of the research on tracked vehicle ride dynamics and manoeuvrability is confined to operations on rigid surfaces. To achieve a realistic evaluation and prediction of the dynamic behaviour of tracked vehicles in the field, the key is to have a better understanding of terrain response to dynamic vehicular loading, including its dynamic stiffness and damping. Challenges that face vehicle dynamicists in this emerging field are identified.     

Dynamics of Tracked Vehicles

SUMMARY

This paper provides a brief review of the state-of-the-art of tracked vehicle dynamics, including mobility over soft terrain, ride dynamics over rough surfaces and manoeuvrability. It is found that considerable progress has been made in the development of analytical frameworks for evaluating and predicting tracked vehicle mobility over soft terrain, taking into account the characteristics of terrain response to normal and shear loading. Certain computer simulation models for tracked vehicle mobility have been gaining increasingly wide acceptance by industry and governmental agencies in product development and in procurement. It is also found that most of the research on tracked vehicle ride dynamics and manoeuvrability is confined to operations on rigid surfaces. To achieve a realistic evaluation and prediction of the dynamic behaviour of tracked vehicles in the field, the key is to have a better understanding of terrain response to dynamic vehicular loading, including its dynamic stiffness and damping. Challenges that face vehicle dynamicists in this emerging field are identified.     

An investigation into the effect of suspension configurations on the performance of tracked vehicles traversing bump terrains

This is a theoretical investigation into the effect of various suspension configurations on a tracked vehicle performance over bump terrains. The model developed is validated using published experimental data of the modal characteristics of the vehicle. The desired performance is based on ride comfort via the mixed objective function (MOF), which combines the crest factor of bounce acceleration, bounce displacement, angular acceleration, and pitch angle. The optimisation process involves evaluating the MOF for different numbers and locations of dampers and under different rigid bump road conditions and speeds. The system responses of the selected suspension configurations in the time and frequency domains are compared against the undamped suspension. The results show that the suspension configurations have a significant effect on the vehicle mobility over bump road profiles. For a five-road–wheel half model of a tracked vehicle, the maximum number of dampers to use for ride comfort over these road bumps is three with the dampers located at wheel positions 1, 2 and 5. This confirms the current practice for many tracked vehicles with 10 road wheels. However, it is further shown that the suspension fitted with two dampers at the extreme road wheels offer the best performance over various rigid bump terrains.     

Analytical Wheel Models for Ride Dynamic Simulation of Off-road Tracked Vehicles

This paper outlines various analytical approaches of varying complexities to model the wheel in the ride dynamic formulation of off-road tracked vehicles. In addition to a proposed model, four analytical models available in the literature are compared to study their effectiveness in modeling the wheel/track-terrain interaction for ride dynamic evaluation of typical high mobility tracked vehicles. The ride dynamic model used in this study describes the bounce-pitch plane motion of an armoured personnel carrier (Ml 13 APC) traversing over an arbitrary rigid terrain profile at constant speed. The ride dynamic response of the tracked vehicle is evaluated with different wheel models, and compared against field-measured ride data. The relative performance of different wheel models are assessed based on the accuracy of response prediction and associated computational time. The proposed wheel model is found to perform very well in comparison, and is equally applicable for the case of wheeled vehicles.     

Haptic interface for intuitive teleoperation of wheeled and tracked vehicles

In this paper, a novel haptic interface is proposed for general teleoperation of wheeled and tracked vehicles. The new mechanism of the proposed haptic interface, shown in Figure 1, not only allows human operators to easily teleoperate various types of target vehicles, including car-like vehicles, mobile robots, and tracked vehicles, but also improves the operator??s perception of the target vehicle??s operating status and its environment by introducing a ??cornering feel?? to the field of vehicle teleoperation. In addition, the proposed interface enables human operators to give commands to (or drive) the target vehicle in a way that is traditionally carried out by direct control or driving. Experiments were completed to carefully evaluate and test the performance of the proposed interface. The results show that the developed haptic master device is sufficient and suitable for general wheeled and tracked-vehicle teleoperation.     

Performance of spade-less wheeled military vehicles with passive and semi-active suspensions during mortar firing

Many armies are replacing heavy slow tracked vehicles with their lighter wheeled counterparts for their high mobility and better shoot and scoot capabilities. These features make the vehicle hard to track and target in counter-battery fire. However, when firing high calibre guns, spades are needed to connect the vehicle chassis to the ground, so as to transmit parts of the large firing force directly to the ground. Use of spades hinders the vehicle mobility, while elimination of them paves the way for having quicker and more mobile wheeled vehicles. In this article, vibration response of a spade-less High Mobility Multi-purpose Wheeled Vehicle with a mounted mortar is studied and controlled using stock passive, optimised passive, and optimised semi-active dampers as primary suspensions. The spade-less vehicle with optimised passive and semi-active dampers has a better response in heave, pitch, and fore-aft motions and can fire with better accuracy compared to a spade-less vehicle with stock passive dampers. Simulation results indicate that the spades can be removed from wheeled military vehicles if the precautions are taken for the tyres.     

Experimental study on mobility of a vehicle with CTIS in soft soil

Recently, the domestic military vehicles currently being developed are installed with a central tire inflation system (CTIS) to control the pressure of tires to increase the contact area between the tires and the ground and improve mobility on soft soils. On the other hand, it is difficult to find technical data based on experiments for designing a CTIS. In this study, to obtain the technical data to set proper pressures according to road conditions a range of mobility tests were performed on soft soil roads, such as sand and clay, according to the CTIS operating modes to obtain the technical data to set proper pressures according to the road conditions. The characteristics of the mobility and its correlation with the tire pressures in each operating mode were analyzed. The results confirmed that a wheeled vehicle with a CTIS showed better performance on soft soil than a vehicle without a CTIS.     

横风下π型断面大跨桥上汽车气动特性风洞试验（双语出版）

准确获得车-桥系统气动力是评估强风作用下桥上车辆运行安全性和舒适性的基本前提，为此必须考虑车辆与桥梁间存在的显著气动相互干扰。以山区大跨桥梁常见的π型断面主梁和集装箱货车为研究对象，设计并制作了1：32几何缩尺比的桥梁和车辆刚性测压模型，通过风洞试验测试了典型车-桥组合工况下车辆表面的风压分布，分析了前、后车辆干扰作用、车辆横向距离和车道组合方式等对桥上汽车气动特性的影响，并进一步分析汽车表面的风压值分布，以探究汽车气动力系数变化的机理。研究结果表明：前、后车辆间的干扰、车辆横向距离的改变对汽车的侧向力系数、阻力系数和升力系数均有较大影响，但对汽车的力矩系数影响较小，且汽车的力矩系数具有一定的离散性；车道组合方式中测试车辆位置的改变对汽车气动特性的影响大于干扰车辆位置的改变对汽车气动特性的影响，且车辆组合方式的改变对汽车的力矩系数基本没有影响；受桥梁π型主梁断面的影响，汽车侧向力系数的变化趋势与Coleman规律下的变化趋势不同。     

高速公路事故现场隔离路锥布设车引导系统研究

目前高速公路交通事故现场隔离路锥自动收放车主要依靠驾驶员凭经验操作,路锥布设车需要实现智能引导并完成路锥的最优化布设隔离.对路锥布设车的智能引导需求进行分析,基于高速公路事故现场隔离规范设计了引导系统规则.建立基于车速反馈的路锥布设时机控制策略,实现路锥纵向布设时机控制.基于路锥布设车平台开发了布设引导系统,并开展实车实验.结果表明,当路锥车速度分别为5 km/h和10 km/h时,相比于布设引导系统启动前,启动布设引导系统后的布设间距误差平均值分别同比下降72.46%和72.90%,累计布设距离误差分别同比下降72.62%和73.15%.一定程度上提高了路锥自动收放车的智能化和信息化,并为未来路锥车自动驾驶引导系统研究提供参考.      

Lateral dynamics of single unit skid-steered tracked vehicle

In the design and development of high-speed tracked vehicles, it is necessary to have an understanding of the interrelationship between the terrain factors and the vehicle characteristics during steering. The handling behavior of skid-steered tracked vehicles is more complex than that of wheeled vehicles because of non-linear characteristics arising from the sliding interface between the track and the ground. In the present work, a five degree-of-freedom (DOF) steering model of a tracked vehicle is developed, and the handling behavior during non-stationary motion is studied when operating at high and low speeds. It is demonstrated that the inclusion of roll and pitch DOF changes the steering response when compared to the response from three DOF models proposed earlier by several researchers. This is due to the strong coupling between the pitch and yaw motions. The effect of the initial forward velocities on the trajectory of the vehicle during non-stationary motion is also studied. It is observed from the results that the stability is influenced by the type of steering input, steering ratio and vehicle forward speed.