抗滑桩在重庆云开公路滑坡整治工程中的应用

根据某工程实例,分析了滑坡的成因及影响因素,对滑坡稳定性进行计算和分析,采用后缘清方减载加坡脚附近设置抗滑桩治理该滑坡是安全、合理、经济的方案。为以后的工程提供一定的借鉴。     

Dynamic analysis and control of an anti-lock brake system for a motorcycle with a camber angle

This paper analyses the dynamic response of a motorcycle with an anti-lock brake system (ABS) and camber or steering angle. Most studies have assumed that motorcycles brake in a straight line – that is, without a steering or camber angle. In this work, the performance of an ABS modulator is designed and analysed at first. Then, a controller is designed for motorcycle turning. The controller uses angular acceleration and the pressure value in brake calipers on the front and rear wheels, camber angle and lateral acceleration as commands to control brake pressure on each wheel to prevent wheel locking. The equation of motion for a motorcycle is based on Weir's equations. This motorcycle model combines a mathematical equation of the ABS modulator, tyre model and controller in simulations.     

轿车外流场及气动噪声的建模与仿真

汽车高速运行时会产生空气动力学噪声,这对汽车乘坐的舒适性、车内乘客的相互交流都会有十分不利的影响。通过CFD手段,采用大涡模拟方法和Lighthill理论,对汽车外流场进行了计算和声学分析。结果表明,CFD不仅可以提供该车气动噪声特性,而且指出前挡风玻璃与车顶连接处、后视镜的造型、车门把手存在优化可能,这为进一步降低该车的风噪提供方向性指导。     

PALIO后桥应变疲劳分析

为解决PALIO后桥国产化过程中寿命达不到要求的问题，采用电测法测得了进口件和几种工艺条件下的国产件PALIO后桥在扭转台架疲劳试验中的主应变幅度。当取有效应变集中系数为1.3时，根据Coffin-Manson公式，运用PALIO后桥用钢的应变疲劳性能计算得到的疲劳寿命与实际台架疲劳寿命相符。     

微型电动汽车后悬架设计

在当今社会,汽车已经发展成人们日常生活中的代步工具,更快更舒适成为了今后汽车的研究方向,因此悬架系统成为了人们首要的研究目标。本设计以两座电动汽车后悬架为研究对象,通过对两种类型的悬架的优缺点进行对比,选取最适合两座电动汽车后悬架的悬架类型,采用非独立悬架以达到制造简便、方便维修且结构简单的目的。对后悬架的弹性元件和减震器进行计算,确定其弹性元件和减震器等零部件的具体数值并进行校核,确保计算所得的数据符合设计要求,并运用CATIA建模。     

追尾碰撞主动头枕的控制策略研究

追尾碰撞事故导致挥鞭伤,造成了很大的社会经济支出。根据生物力学的研究成果,在追尾碰撞发生时,减小头枕与头部的水平距离可以降低挥鞭伤的程度。为了弥补传统纯机械主动头枕响应滞后的不足,采用机电结合的方法,根据自主巡航系统提供的信息,提前判断并启动头枕,从而保护乘员。分析了追尾碰撞中颈部的保护策略,研究了追尾防撞和预警算法,根据基于安全间距的追尾防撞模型和安全度评定算法编写了可视化的判断算例。算例具有如下功能:根据输入的跟车信息判断安全度;追尾碰撞NIC值的估算;碰撞后两车的运动追踪。     

中型客车后视镜抖动的分析与改进

针对某中型客车后视镜在怠速工况下抖动大的问题,采用CAE仿真与试验分析相结合的方法。分析表明,后视镜的1阶和2阶模态频率分别与发动机的1阶和2阶激励频率很接近,后视镜的抖动是由发动机的1阶和2阶激励引起共振。最后对后视镜骨架进行优化改进,顺利解决了怠速工况后视镜振动大的问题。     

Automobile aerodynamics influenced by airfoil-shaped rear wing

Computational model is developed to analyze aerodynamic loads and flow characteristics for an automobile, when the rear wing is placed above the trunk of the vehicle. The focus is on effects of the rear wing height that is investigated in four different positions. The relative wind incidence angle of the rear wing is equal in all configurations. Hence, the discrepancies in the results are only due to an influence of the rear wing position. Computations are performed by using the Reynolds-averaged Navier-Stokes equations along with the standard k-ε turbulence model and standard wall functions assuming the steady viscous fluid flow. While the lift force is positive (upforce) for the automobile without the rear wing, negative lift force (downforce) is obtained for all configurations with the rear wing in place. At the same time, the rear wing increases the automobile drag that is not favorable with respect to the automobile fuel consumption. However, this drawback is not that significant, as the rear wing considerably benefits the automobile traction and stability. An optimal automobile downforce-to-drag ratio is obtained for the rear wing placed at 39 % of the height between the upper surface of the automobile trunk and the automobile roof. Two characteristic large vortices develop in the automobile wake in configuration without the rear wing. They vanish with the rear wing placed close to the trunk, while they gradually restore with an increase in the wing mounting height.     

Performance and Safety Requirements for Auxiliary Steering Equipment Explained by Means of the Example of BMW's Active Rear-Axle Kinematics (ARK)

SUMMARY

Since the end of 1991 BMW produces a new chassis control system for its 8 series coupé, called Active Rear-axle Kinematics (ARK). It is an electrohydraulic rear axle steering system with a speed-dependent transfer function for rear axle steering angle. It improves driving safety in severe steering maneuvers and reduces driver's stress in everyday driving. Its technology includes a comprehensive fail-safe concept which basically constitutes a dual channel design and monitors the proper system operation in a multi-stage comparison starting at the system inputs and ending at its output.     

后举门气弹簧变形验证方法

在诸多影响后举门尺寸状态的因素中,气弹簧力导致的后举门变形糅合了举门位置的整体移动以及举门本身的局部变形,成为影响后举门尺寸状态的一大难点.文章在综合已有的后举门气弹簧变形验证方法的基础上,结合扫描技术,研究了一种新方法,借助于软件,可以有效地将局部变形和整体变形分离开来,为零件的调整和优化提供了可靠依据.     

汽车后视镜后视野要求及测试方法探讨

汽车后视镜的后视野对于行驶安全具有十分重要的作用，本对欧洲，美国，日本及中国关于后视镜的后视野法规和标准进行了分析和比较，详细地探讨了后视野中眼点的确定确定方法，结合实际工作情况，总结了四种后视野测试方法。     

Rear wheel torque vectoring model predictive control with velocity regulation for electric vehicles

In this paper we propose a constrained optimal control architecture for combined velocity, yaw and sideslip regulation for stabilisation of the vehicle near the limit of lateral acceleration using the rear axle electric torque vectoring configuration of an electric vehicle. A nonlinear vehicle and tyre model are used to find reference steady-state cornering conditions and design two model predictive control (MPC) strategies of different levels of fidelity: one that uses a linearised version of the full vehicle model with the rear wheels' torques as the input, and another one that neglects the wheel dynamics and uses the rear wheels' slips as the input instead. After analysing the relative trade-offs between performance and computational effort, we compare the two MPC strategies against each other and against an unconstrained optimal control strategy in Simulink and Carsim environment.     

FSAE赛车悬架系统结构设计

为配合建立中国大学生方程式汽车大赛(FSAE)赛车的虚拟样机模型,根据FSAE赛事规则要求,对赛车悬架系统进行了结构设计。根据设计思路对轮辋、轮距及前后悬架立柱等相关部件进行了选择与设计,在确定采用不等长双横臂式悬架类型的基础上对弹性元件、减振器和导向机构的主要结构尺寸进行了设计计算,并应用软件Pro/E进行了三维建模设计,同时在SolidWorks环境下对前后摇块进行了强度校核。结果表明,前后摇块的最大合位移分别为4.260×10-3,2.838×10-2mm,最大变形均很小,设计的FSAE赛车悬架系统能够满足参赛要求,为进一步的实车研制提供了参考依据。     

多连杆后悬副车架结构及衬套优化设计

结合某车型开发工作,针对该车型所采用的新型四连杆后悬架系统,采用先进的多学科优化技术对后桥结构及衬套刚度进行全面优化设计,并对遗传算法、模拟退火及混合多梯度探测等多目标优化算法在该系统中的应用进行了详细的对比论证。     

轿车后桥疲劳寿命的数字化预测研究

以某轿车后桥为例,介绍了疲劳寿命计算的理论基础和建立后桥精确有限元模型的方法。分别应用准静态法和随机振动法计算了后桥的疲劳寿命,讨论了频响分析带宽对振动疲劳分析方法的影响以及两种不同疲劳计算方法的区别和应用范围。结果表明,应用有限元仿真和试验相结合的方法可以有效地预测轿车关键零部件的疲劳寿命。     

T-car后桥台架疲劳试验研究

采用台架疲劳试验模拟了T-car后桥在道路试验中的受力状态。通过对T-car后桥进行的总成扭转试验、总成单侧侧向力试验和总成单侧纵向力试验,测得了各测点在疲劳循环中的应变幅、主应变幅度,并采用Coffin-M anson公式估算了寿命。试验表明,台架疲劳试验能反映路试时的疲劳损伤,根据T-car后桥用钢的应变疲劳性能估算得到的疲劳寿命与实际路试结果相符。     

基于实际载重的汽车前后轴制动力分配系统设计

汽车在生活和生产中日益变得不可或缺,对汽车安全性又提出了更高的要求。汽车前后轴制动力分配对汽车安全性具有重大影响。针对前后轴制动力分配的问题,分析比较了目前各种分配方式的不足,并建设性地提出了基于实际载重的汽车前后轴制动力分配的控制方法。建立并详细阐述了该控制方法的理论模型及相关的约束条件。对该控制方法进行了实例计算分析和仿真实验,并对实验结果做了说明和总结。     

电驱动桥开发设计流程的研究

电驱动后桥作为集成化的设计可以减少整车空间体积的占用,为整车电池、电机控制器等零部件的布置提供更多的空间,在纯电动商务车中有着很大的优势,文章阐述了一种电驱动后桥开发设计流程的研究方法,为电驱动后桥的开发设计提供更多的研究方法。     

A methodology to increase driver trust in rear-obstacle warning systems with imperfect sensing results — Proposal for a warning system using sensor reliability information

Driver's workload tends to be increased during driving under complicated traffic environments like lane-changing operation. In such cases, rear collision warning is effective for reduction of cognitive workload. On the other hand, it is pointed out that false alarm or missing alarm caused by sensor errors leads to decrease of driver trust in the warning system and it can result in low efficiency of the system. Suppose that sensor reliability information is provided in real-time. In this paper, we propose a novel warning method to increase driver trust in the system even with low sensor reliability by utilizing sensor reliability information. We investigate the effectiveness of the warning methods in high and low workload situations by driving simulator experiments.     

基于ADAMS-Car的汽车建模与仿真研究

为了有效应用多体动力学软件ADAMS/Car进行车辆动力学研究,介绍并建立了包括汽车底盘、车身、转向、前后悬架、轮胎、动力总成等分系统的汽车整车模型,将整车系统简化为单自由度的质量-刚度-阻尼系统,建立微分方程,分别应用Matlab/Simulink和ADAMS/Car两种仿真方法,对整车模型进行了正弦激励输入下的仿真,比较计算结果可知达到稳态后的车身响应曲线非常吻合。研究表明:基于ADAMS/Car建立的整车多体动力学模型准确,可以用于实际车辆的仿真研究。