履带车辆地面力学仿真研究

ATV(ADAMS tracked vehicle)是基于虚拟样机分析软件ADAMS的一个专门分析履带车辆的工具箱。该文通过对土壤弹塑性力学本构关系的引入，对ATV中的三种车辆地面力学模型进行了研究，分析了三种地面模型的参数对车辆行驶性能的影响，得出了各个地面模型所适合的实际路面。最后，建立履带车辆模型，对三种地面模型进行了试验仿真分析，为后期的车辆行军试验仿真提供了路面依据。     

基于ATV的履带车辆悬挂系统仿真

研究履带车辆动态系统,使运动车辆缓和在路面行驶时受到的振动,使用ATV工具箱在ADAMS中建立了某履带车辆悬挂系统的动力学模型,应用多体动力学理论分析了车体、悬挂系统、负重轮、履带、路面之间的相互作用,给出了与各参数相对应的关系表达式,并描述了履带车辆运动学方程以及动力学方程.以标准梯形障碍物作为路面输入选取的各种参数进行了仿真,并将实车的车体固有频率、负重轮固有频率与计算得出的对应量进行比较,结果显示二者基本吻合,从而说明所建立的仿真模型是可信、有效的,可为设计提供参考.     

高速履带车辆轮履脱离机理分析与仿真研究

高速履带车辆履带脱轮问题是一项非常复杂的工程技术问题。为降低履带车辆在行驶过程中履带脱轮发生概率，以力学理论为基础，分析了履带脱轮时诱导齿与负重轮的相互作用关系，并以ADAMS软件为仿真平台建立了可测试履带从负重轮脱出难易程度的多体动力学模型。模型充分考虑履带、诱导齿及负重轮设计参数，利用正交试验设计方法开展履带刚度特性、诱导齿及负重轮设计参数对履带脱轮影响的仿真研究，仿真结果表明，不同的设计参数对履带脱轮影响的灵敏度不同。将试验数据进行神经网络拟合，对拟合后的表达式进行GA算法寻优，找到防止履带脱轮的因素最优值，使履带系统的运行稳定性得到了显著提高。     

基于弹簧振子理论的装甲车辆振动过程仿真

该文研究内容为车辆(轮式、履带)在不平路面行驶和通过障碍时的平顺性问题。利用状态方程法建立了包括随机和确定路面轮廓、三维车体等较为通用的车辆行驶平顺性模型，并针对行驶振动中车轮与悬架的碰撞建立了专门模型。对某型装甲车辆进行了计算机仿真和验证，对模型的精度和有效性进行检验和评估。结果证明所建立的车辆-地面系统模型是有效的。该模型和建模采用的方法为装甲车辆的系统设计和动力学分析提供了一条途径。     

履带车多刚体建模与仿真分析

首先以车辆地面力学理论为基础,分析了典型的履带与地面相互作用关系及其在RecurDyn/Track(LM)程序中的处理,分别定义了两种典型地面土力学参数,从而建立了基于Bekker理论与Janosi & Hanamoto理论的循环动载荷作用下履带与地面相互作用力学模型;同时分析了履带系统各部件之间的接触力学模型,定义各接触参数及约束关系,从而准确合理地建立了履带车多刚体模型,通过施加运动函数,实现模型在典型地面参数下的行走特性仿真分析,仿真结果与理论分析及实际情况相符合,互为验证,从而为进一步深入研究提供了理论依据与有效分析手段.     

高速履带车辆转向机理仿真

该文运用系统分析的方法,研究坚实地面条件下高速履带车辆转向过程的理论及其计算机仿真.以履带滑动转向理论为基础,考虑影响履带车辆转向的诸多因素(质心位置、负荷分布等),建立了履带车辆转向过程动力学模型.并且为求解模型中的微分-代数混合方程,编写相应程序进行了仿真计算,对高低速两种情况下高速履带车辆的转向过程进行了计算机仿真实验,仿真计算的结果与实车野外实验的结果呈现一致性.该文特别在分析履带车辆高速转向过程中研究了离心力通过履带接地压力而对履带车辆转向过程的影响.     

基于RecurDyn的滑转对履带车辆加速性能影响研究

采用多体动力学仿真软件RecurDyn的履带车辆子系统Track(HM),建立履带车辆多体动力学模型,并在MATLAB/Simulink下建立了整车动态系统仿真模型。对履带车辆在硬、软两种地面的加速过程进行动力学仿真和对比分析,着重讨论在不同滑转的条件下履带车辆的加速性能以及滑转率对加速性能的影响,为履带车辆加速性能的研究与滑转的控制提供指导。     

电传动履带车辆转向行驶性能仿真分析

该文首先采用一种优选电传动方案建立了新的电传动履带车辆模型。然后在对电传动履带车辆转向行驶基本理论分析的基础上，对电传动履带车辆的转向行驶性能进行了仿真分析。结果表明：履带车辆采用电传动在转向性能方面具有很大的优势，可以实现小半径甚至是原地中心转向，转向为无级的，且转向的灵活性和快速性很好。再生转向时产生的再生能量很大，可以通过控制充分利用再生能量。为在不同的地面情况下提高转向的灵活性和快速性，应尽量在转向前降低车速，使驱动电机在低速大扭矩下工作，由于低速时车辆实现的转向半径可以很小，转向角速度可以很大，从而实现快速、灵活转向。     

履带车辆高速转向动力学仿真

采用多体动力学仿真软件MSC Adams 的履带车辆工具箱ATV,建立某型履带车辆三维动力学模型,对履带车辆在硬、软两种地面的高速转向过程进行动力学仿真和对比分析,着重讨论履带车辆在软地面高速转向的动力学特性,为履带车辆转向性能的研究与高速转向的正确操作提供指导.     

履带车辆软土通过性能影响因素仿真

研究履带预张力对车辆软土通过性能的影响规律. 采用MSC Adams软件的ATV工具箱建立履带车辆与地面的相互作用模型. 仿真结果表明,适当增加履带预张力可有效降低车辆的平均最大压力并提高其挂钩牵引性能. 该结论对履带车辆的设计者和使用者有一定的指导意义.     

Vehicle Dynamics Modeling and Electronic Stability Program/ Active Front Steering Sliding Mode Integrated Control

Chassis integrated control can significantly improve vehicle handling stability and comfort. Because of the complexity of the problem, it has attracted significant research attention. We built a vehicle nonlinear dynamic model with multi‐degree freedom, including body movement, wheel movement, and electronically controlled hydraulic power steering system. We compared the magic formula tire model, Dugoff tire model, brush tire model, and LuGre dynamic friction tire model and steady model. The precision of the model was verified by a comparison between simulation results and the real vehicle test results. Then, based on the vehicle dynamics model, an AFS (active front steering) controller was designed based on sliding mode variable structure control, and an AFS and ESP (electronic stability program) integrated coordination controller was proposed. Finally, based on the nonlinear tire model and multi‐DOF (degree of freedom) vehicle model, sinusoidal and step steering angle input simulation analysis was proposed on different road friction coefficients. The results show that the vehicle has better response characteristics with coordinated control strategy when compared with AFS and ESP only control. The evidence suggests that the proposed integrated control system in this paper can improve vehicle stability and safety.     

基于计算机虚拟样机技术的轿车悬架性能研究

采集广德试车场操纵性与平顺性试验环路的道路载荷谱,利用nCode软件对道路载荷谱进行编辑与处理,得到随机短波路、沥青振动带等多种不同路面的道路载荷,导入ADAMS中进行悬架动态仿真。因为传统的基于静态K&C特性分析的系统参数设计不足以满足复杂工况下整车对悬架的性能要求,而动态K&C试验具有更精确的响应结果,更能反应悬架的实际使用状态。最终在动态K&C试验台进行试验,对比动态、静态与台架试验的结果,验证了动态K&C仿真与试验结果更加接近,具有更精确的仿真结果。所以,对汽车悬架的动态特性研究对工程应用具有一定的帮助作用。     

车辆避障驾驶控制方法研究

受机器人基于人工势场的路径控制方法的启发,在吴镜开等提出方法的基础上,提出了车辆避障控制机制。定义了基于停车视距的车辆行驶动态目标位置;依据人工势场建模原理构建道路和障碍物势场;为了平滑车辆行驶路线,采用了贝塞尔（Bezier）曲线车辆轨迹拟合的方法;针对车辆系统是典型的非完整控制系统,将车辆运动学模型转换为链式系统模型,实现相对简化系统控制设计目的。仿真控制实验说明这种方法对车辆避障控制具有较好的轨迹跟踪效果和全局稳定性。     

An analytical investigation of isolation systems for cab ride

The dynamic performance capabilities of heavy duty trucks with suspended cabs are identified using a linearized model of heave-fore-aft-pitch dynamics. Cab acceleration levels and dynamic deflections are determined for vehicle performance on a randomly irregular road surface. The important trade-offs that limit the overall design are illustrated.     

基于ADAMS的脉冲路面输入平顺性仿真分析

以某皮卡车为研究对象。利用ADAMS／VIEW软件建立了包括前后悬架、轮胎、车身、转向系和人-椅系统等在内的整车多刚体动力学模型,并对建模中的若干关键问题进行了详细的论述。运用ADAMS软件对建立的整车多体动力学模型成功地实现了脉冲路面输入下的平顺性仿真分析。将仿真所得结果与该车试验所得结果进行了对比,结果表明数据吻合较好,从而认为整车模型建立准确。并为进一步对该车做设计分析打下了良好的基础。     

Calculating road input data for vehicle simulation

Multibody system simulation is an important tool in the development process in vehicle engineering. Without much effort, different vehicle variants and designs can be simulated, analyzed, and optimized. This is of particular relevance in an early stage of development, when no physical prototypes are available yet. In order to simulate the vehicle models under realistic conditions, suitable input data is needed for the simulation. We present an approach to derive a virtual road profile based on a tire-surrogate model, measured spindle forces, and a multibody system model of the measurement vehicle. In contrast to the measured spindle forces, the road profile together with the tire-surrogate model can be used to simulate other vehicle variants, for which no measurements are available. The road profile is derived by solving an inverse control problem. We formulate this inverse problem in the context of system simulation and provide a short mathematical analysis. Additionally, we discuss a solution approach, the method of control-constraints, which is also applied in a numerical simulation study to compute a virtual road profile.     

Reality of virtual damage identification based on neural networks and vibration analysis of a damaged bridge under a moving vehicle

Presented here is a reality of virtual damage detection and vibration behaviour study of a discrete beam-like bridge with one or several non-propagating edge cracks subjected to a moving vehicle. In this model, the simply supported beam elements are replaced by a range of rigid bars, which are connected by transverse and rotational springs, while the mass and rotational moment of inertia may be lumped at various points along the beam. The adopted vehicle model here is a four degrees-of-freedom, two axes half-vehicle model with tires flexibility and linear suspensions. Damage can be modelled by altering the spring stiffness equation at the crack position according to predictions, which allows the inclusion of simple or complex damage. To simplify, damage is represented here by an open crack, and stiffness of a given element with damage is calculated by fracture mechanics. Both the discrete element and finite element methods are used to investigate vibration analysis of a discrete beam model subjected to a moving vehicle to confirm model feasibility in vibration analysis under a moving vehicle. Besides, some dynamic response laws are obtained. Considering an irregular road profile, the effects of the moving vehicle velocity, the moving vehicle mass, the crack location and the crack depth on dynamic response of a beam-like bridge are analysed by a numerical example, combining a vehicle–bridge coupled vibration MATLAB program with ANSYS. In addition, the neural network is used to identify the damage of the structure. Numerical results of the numerical model predictions, compared with those obtained from the continuous elements beam, support the accuracy of the discrete elements beam model in both cases of undamaged beam and damaged one. The evidence for condition assessment and damage identification of bridge is obtained from this simulation as obtaining the vibrational characteristics of the damaged beam structure subjected to a moving vehicle. And the inversion results show that the neural network method can identify the injury location and injury size of the structure accurately.

     

基于虚拟仿真技术的车架动态响应特性分析

采用ALGOR有限元分析软件对车架进行模态分析,得出了前10阶振型及固有频率。运用二自由度汽车振动模型,建立了系统的运动微分方程并利用Matlab中的Simulink模块对车架的振动情况做出了仿真。利用路面谱仿真得到的路面激励信号作为输入,对车架进行动力响应模拟,得到了车架在典型路面上的动态响应特性,为车架的结构优化提供了理论依据。     

基于有限元仿真的特种越野车结构疲劳寿命预测

为缩短新车开发周期、节约样车制造费用,给车辆轻量化设计提供参考,在计算机仿真环境下预测了某特种越野车关键部件的疲劳寿命。基于该车结构有限元模型动力学计算的频响结果,对计算模型施加不同车速下等级路面位移谱,得到了不同车速不同级别路面下该车关键部件的应力响应谱,并在此基础上运用随机疲劳理论预测了该车的疲劳寿命。所研究的内容为车辆的疲劳寿命预测提供了较为可靠的流程和方法,所预测寿命结果在合理范围内,并提供了关键部件疲劳寿命的薄弱位置。     

车辆线控转向路感模拟控制研究

针对车辆线控转向路感模拟控制受外界扰动大、建模困难等问题,基于线性自抗扰控制(LADRC)技术设计了一种车辆线控转向路感模拟控制算法.建立了线控转向路感控制仿真模型,包括驾驶员模型、线控转向系统模型、两自由度车辆模型、轮胎模型及控制器模型等,在给定道路函数条件下进行了系统仿真验证.结果表明,所设计的线性自抗扰控制器可以...