Numerical modeling and dynamic simulation of automotive power window system with a single regulator

Door glass position errors that occur when an automobile door glass goes up and down not only reduce the basic performance of the door glass in terms of sound- and water-proofing, but also decrease the life span of the glass run and belt. Thus, there is a need for understanding the dynamic behavior of a door glass in order to reduce these errors. In this research, we analyzed the door glass behavior by developing a dynamic numerical analysis model for a single rail regulator type of door glass lifting system. We modeled the glass run and belt lip load as a non-linear spring-damper system to reflect changes in the lip load caused by door glass position errors in the analysis. We also introduced local coordinate systems to find door glass position errors during the lifting process. By using our model, the time spent on the up and down motions, the current, and the lifting resistance could be predicted with 4 %, 11 %, 3 % and 4 % of error, respectively, comparing with the test data. We confirmed the effects of imbalances and boundary conditions in the load and moment which occur during the door glass lifting process. We also found that the lip reaction force, coefficient of friction, overlap length and position of the lift line cause door glass position errors.     

Vibrational characteristics of automotive transmission

A mathematical model of an automotive transmission is developed, that considers the flexibility of the shafts, bearings, and gear teeth, and gyroscopic effects of geared rotors. The transverse, torsional, and axial motions are strongly coupled due to helical gearing. The excitation forces acting on the automotive transmission are classified into first, second, and third grades, based on the magnitudes of the forces that are determined by the perturbation method. The excitation forces are caused by the mass imbalances among gears, misalignment of shafts, clearance and non-linear deformation of bearings, transmission errors, and the periodic variation of the gear mesh stiffness. A bench test on loading conditions is carried out for the third speed of the automotive transmission. The experimental results of vibration characteristics are compared with those from theoretical analysis. The results show good agreement, i.e., within a tolerance of 3.3%.     

Experimental study of the flow characteristics in an automotive HVAC system using a PIV technique

Air flow inside an automotive HVAC module was visualized using a high-resolution PIV technique with varying temperature control modes. The PIV (particle image velocimetry) system used for the experiment consisted of a 2-head Nd:YAG laser (125 mJ), a high-resolution CCD camera (2 K × 2 K), optics and a synchronizer. A real automotive HVAC module was used as a test model, and some of its casing parts were replaced with transparent windows to capture the flow images of the laser-light-sheet illumination. In addition, instant velocity fields were measured for three different temperature control modes by adjusting the temperature baffle. Characteristics of the air flow inside the automotive HVAC were then evaluated based on the time-averaged PIV data. Results from the experiment showed that flow for the warm mode loses more momentum due to its complicated flow path. Thus, the present PIV data can be used to validate numerical prediction and to improve the performance of HVAC modules.     

Study on lateral dynamic characteristics of vehicle/turnout system

Based on Chinese No. 12 high speed, single-way swing nose rail concrete sleeper turnout, a comprehensive vehicle/turnout system coupling dynamic model has been established in this paper, and the lateral and vertical dynamic characteristics of vehicle/turnout systems have been simulated while the car passes through the turnout zone on divergence. These dynamic characteristics show that the lateral impact and vibration of the systems caused by the wheel/rail contact and irregularity are very intensive, especially at the switch zone and nose area of the turnout, and the lateral dynamics of the turnout system, such as lateral stability, vibrating responses, impacting and the allowable passing velocity force between the wheelsets and the switch rails are much more complicated than that of the vertical ones.     

Study on lateral dynamic characteristics of vehicle/turnout system

Based on Chinese No. 12 high speed, single-way swing nose rail concrete sleeper turnout, a comprehensive vehicle/turnout system coupling dynamic model has been established in this paper, and the lateral and vertical dynamic characteristics of vehicle/turnout systems have been simulated while the car passes through the turnout zone on divergence. These dynamic characteristics show that the lateral impact and vibration of the systems caused by the wheel/rail contact and irregularity are very intensive, especially at the switch zone and nose area of the turnout, and the lateral dynamics of the turnout system, such as lateral stability, vibrating responses, impacting and the allowable passing velocity force between the wheelsets and the switch rails are much more complicated than that of the vertical ones.     

车用三效催化转化器排放特性的数值模拟

将催化转化器的几种化学反应机理与控制方程结合在一起建立了转化器的数学模型，对其进行数值求解，结果与实验值吻合较好，验证了模型的正确性，为以后进一步提出更加准确的数学模型提供了一种可靠的方法，具有重要的应用价值。     

美国劳工部关于汽车经销行业的调查报告

汽车经销商是汽车厂商和消费者联通的桥梁和纽带.据美国汽车经销商协会(NADA)数据表明,新车销售收入占据了新车特许经销商(轿车和卡车新车经销商)总收入的一半以上,汽车销售业为新车经销商的其它部门增加了盈利来源.通过新车销售,经销商可以从汽车后市场、维修和客户服务获得收入,并且也为未来二手车的回收和再销售提供了一定的保障.     

浅析企业标准化与汽车产品3C认证的关系

标准化工作是企业一项重要的基础工作,也是汽车产品3C认证中不可缺少的内容。汽车产品3C认证依据是产品标准,经认证机构确认并通过颁发认证证书和认证标志来证明某一产品符合相应标准,可增强市场竞争力。只讲标准化不能有力地推动标准实施,汽车产品3C认证能推动标准的实施。     

CFD analysis of the flow in an automotive headlamp

In order to predict water condensation in an automotive headlamp at an early stage of the development process, CFD analysis of the flow in the headlamp was attempted.First, CFD analysis was conducted on the headlamp unit removed from a vehicle. The result was similar to the experimental result, thus the validity of this analysis was confirmed. Furthermore, water condensation in the headlamp on the vehicle was studied, based on the CFD analysis and the experiment. The results show that the water condensation in the headlamp is not only influenced by the velocity and temperature distribution in and around the headlamp, but also by the absolute humidity near the headlamp vents.     

基于能量解耦的汽车动力总成悬置系统优化设计

为了解决某款车的动力总成悬置系统振动问题,结合多自由度系统振动解耦和固有频率匹配理论,应用ADAMS建立动力总成悬置系统模型进行仿真分析。同时以解耦率目标函数,通过MATLAB软件中的遗传算法对悬置系统进行了优化。结果表明,对悬置刚度进行优化能有效提高解耦率,改善系统的NVH性能。     

汽车交通事故现场勘查与再现技术探讨

随着汽车工业和交通运输业的高速发展,交通安全形势异常严峻,汽车交通事故现场勘查与再现技术成为交通安全研究领域的重要课题。本文对已运用到汽车交通事故现场勘测与再现中的摄影测量技术和计算机图像技术进行了分析研究,并提出了事故现场勘查与再现的新技术方案。     

基于神经网络的车用汽油机失火程度模糊诊断研究

提出了利用排气中ＨＣ、ＣＯ２和Ｏ２浓度诊断车用汽油机失火程度的诊断方法和描述汽油机失火程度的模糊评价指标，并建立了该评价指标与排气中ＨＣ、ＣＯ２和Ｏ２浓度间关系的神经网络模型。利用该模型对汽油机失火程度进行了诊断研究，并给出了部分诊断结果。     

Computational and experimental investigation of the unsteady flow structures around automotive outside rear-view mirrors

The unsteady flow field around two automotive outside rear-view mirrors is investigated. This study includes comprehensive experimental and computational approaches in order to characterize the complex flow structures in the wake of the mirrors. The experiments were carried out in a wind tunnel which included the measurements of the instantaneous and averaged velocity fields as well as mean and unsteady surface pressure distributions. The simulations were performed using Large Eddy Simulation (LES). The LES approach (particularly with the dynamic subgrid viscosity model) provided good agreements with the experiments for the velocity and the surface pressure distributions. The experimental and the computational results of this study will be used as a benchmark to validate the current and the future CFD development and the subsequent aero-acoustic computations.     

客车空调的正确使用和维护

炎热的夏季即将到来,为能达到舒适的乘车环境,驾驶员要对客车的空调进行一次全面的检查和保养.下面向大家介绍一下客车空调的正确使用方法和维护事项,以确保客车空调系统的正常使用,保证用户夏季的正常运营.……     

Analysis of an automotive ground system based on its steady-state model

As more electrical equipment is installed and larger currents are required in vehicles, the automotive ground system becomes more important to guarantee the stable operation of the equipment and efficient power consumption. In this paper, an automotive ground system is analyzed in a steady-state condition, and a simulation model for estimating its ground voltage distribution is described. The automotive ground system is divided into an engine compartment ground and a body ground, and it is modeled as an equivalent resistor network, which is suitable for simulation. By using the developed model, ground voltages are simulated and measurements are taken with a real car. A comparison of the simulation and measurement results shows good agreement, and the validity of the model is confirmed. Then, the factors that dominate the ground voltage level are discussed.     

Requirement-based testing of an automotive ECU considering the behavior of the vehicle

HILS (Hardware In the Loop Simulation) and RBT (Requirement-Based Testing) are widely used to evaluate the performance and reliability of automotive ECUs (Electronic Control Units). The HILS method is used to predict the behavior of ECU-installed vehicles and to evaluate the performance of ECU controllers. RBT evaluates whether the embedded system satisfies the pre-defined requirements. In this study, the behavior of a vehicle is regarded as a system requirement, and an embedded system test procedure that evaluates the system requirement is proposed. In particular, a new method is introduced, which integrates HILS with RBT. Using the proposed method, the behavior of an articulated vehicle equipped with an AWS (All Wheel Steering) ECU is evaluated with RBT software.     

论"汽车发动机可靠性试验方法"

在台架上考核发动机可靠性，采用强化试验方法，其运行范围分为限内，限外两种，前者使发动机所受应力及热负荷不超过使用工况，解决一般性可靠性的问题，后者属超过使用应力，旨在对某些零部件的可靠性作出快速判断，冷热冲击限外试验规范被录用标准；作者推出十条发动机可靠性评定原则。     

驾驶员动态视认特性初探

分析了动态条件下视野的变化规律,通过实车动态实验测定不同速度下标志汉字的视认距离。实验数据结果表明在120km／h以下时,速度对驾驶员的视认距离影响不显著,同时应用心理学与视觉理论对实验结果进行了分析。本研究可为后续交通标志视认性研究提供理论依据,对提高交通安全具有借鉴意义。     

汽车用永磁发电机综述

本介绍了汽车用永磁发电机的现状和市场前景，分析了该电机开发的技术核心，针对性地论述了永磁发电机的结构特点。     

New metal fitting geometry and optimization of the swaging parameters for an automobile power steering hose

To solve the power steering (PS) hose oil leakage problem in automobile applications, a new geometry design of the metal fitting is required, and the swaging conditions applied to the PS hose should be optimized. In this study, a new metal fitting geometry for the PS hose was proposed. A CAE simulation for both the proposed and the conventional metal fittings was conducted, and both the stress and the strain in the PS hose were compared. An experimental verification was also performed with these two different metal fittings. Additionally, the swaging conditions were optimized by the durability cycle time, which was measured in an impulse test of the swaged PS hose. For a more economical production, practical working conditions were also recommended and experimentally verified.