气缸盖垫压力传感器在柴油机中的应用

发动机管理系统的开发在现代发动机开发工作中起着核心作用。一种带有集成于其中的缸内压力传感器的气缸盖垫将会对此作出决定性的贡献。埃尔灵·克林格(ElringKlinger)公司和奇士乐(Kistler)仪器公司正在共同致力于开发这样一种气缸盖垫。其目的在于为汽车工业提供一种能够对燃烧过程进行最佳     

车市低迷诸种变局多

车市低迷，汽车市场、汽车人事、汽车企业变局多，可能本是平常事，但某些传媒一放大，成为汽车重大新闻，颇为引人入胜．其中不乏缺少理智的成分。     

2006年售后服务业将成为汽车市场争夺的焦点

随着我国汽车工业的高速发展，家庭轿车的逐步普及，社会汽车保有量的快速增长，给汽车售后服务业带来了极大的商机和丰厚的利润。如果把整车销售作为汽车市场的“车前市场”，那么维修保养、配件供应、汽车美容、汽车改装等服务都可以称为是汽车后市场。在美国，汽车售后服务业是有名的黄金产业，美国汽车售后服务业协会公布的数据显示：1999年美国汽车售后市场的规模为2582亿美元，从业总人数约370万人，经营场所约49．5万个，汽车维修业的利润达到27％。据统计，     

大型汽车服务企业管理中存在的问题

随着汽车工业的飞速发展，带动了一大批汽车服务企业，其中一部分已经成为当地汽车服务行业的大型汽车服务企业。当然与制造行业中的大型汽车服务企业相比较，这些大型汽车服务企业仍然属于小企业，但是在汽车服务行业中，这些企业却是行业的大鳄和领头兵。本文所讨论的大型汽车服务企业，就属于这个范畴。它包括大型汽车服务集团、大型汽车销售公司、大型汽车服务连锁店、大型汽车4S店、大型汽车维修服务企业等等。     

后汽车与后汽车工程

基于对汽车演变历史的分析和前瞻汽车的发展前景，提出了三个汽车时代、后汽车和后汽车工程的概念。论述了可持续发展是后汽车的特征形态，实现汽车可持续发展是后汽车工程的特征，分析了后汽车工程成为国家工程的原因。     

汽车故障的分段排除法

随着汽车工业的日新月异，传统的汽车维修方式已远远不能满足现代汽车的要求。在针对现代汽车的维修，特别是在高级轿车的维修过程中，汽车零部件的维修已不再是汽车维修的主要工作（因为现代汽车的许多部件不可修复，损坏之后更换新件即可），而准确判断引发汽车故障的原因则成为汽车维修的关键。     

浅解我国汽车过剩

我国的汽车制造业现在正处于飞速发展时期。从目前来看，我国的汽车增加量已超出了我国居民对汽车的需求量，造成了汽车产能过剩。但是，同时我国又是一个发展中国家，汽车的拥有量远远低于发达国家，甚至低于一部分发展中国家。造成我国目前汽车过剩的原因是多方面的，文章就其中的一些方面加以分析，并提出一些对策。     

德国汽车报废管理制度

作为汽车流通体系的最后一个环节，汽车报废处理是实现报废汽车资源回收和循环利用的必然途径，在整个汽车市场和汽车使用循环中占有重要地位。在自然资源日益紧张的今天，完善的汽车报废管理制度不但有利于促进汽车工业和汽车市场的健康可持续发展，而且对保护环境、维护交通安全等也具有重要意义。作为目前世界第二大汽车消费市场，随着中国汽车保有量的迅速增加，每年的报废量也随之增加，因此报废车的处理以及再生利用问题也越来越重要。     

影响我国汽车消费因素的分析

最近几年，出于我国经济发展的需要，国家出台了一系列鼓励汽车消费的政策，一时间汽车成为我国继住房之后又一消费热点，汽车产销量大幅增长，私人汽车消费在汽车总销量中所占比重逐年提高。但另一个不可否认的事实是，我国过高的汽车价格、沉重的税费负担、恶劣的汽车消费环境等在一定程度上也束缚了我国汽车消费的增长，延缓了我国汽车进入家庭的步伐，现简要分析如下。     

汽车维修企业发展策略之我见

随着我国经济的迅猛发展，汽车工业和汽车服务业得到了飞跃的成长和发展。快速增长的汽车保有量为汽车维修行业的发展奠定了坚实的基础，给汽车维修行业带来了巨大的商机。与此同时，激烈的市场竞争，也向汽车维修业提出了新的要求和挑战，汽车维修企业已不能再凭借传统的经验和方式来投资和经营。因此，汽车维修企业如何顺应时代潮流和调整自己的发展战略，是企业生存的关键。     

A vehicle type-based approach to model car following behaviors in simulation programs (case study: Car-motorcycle following behavior)

Traffic simulation models often neglect the important role of motorcycles and assume a flow of various combinations of cars. This paper addresses how much different would be the behavior of a car driver while following a motorcyclist compared to cases in which a car follows another car, along with a segment of an urban highway in the non-congested flow. Recognition of such a difference might help to develop existing simulation models and to improve the behavior of car drivers in such a way to lead to lower accidents with motorcycles. To reach the goal, a GHR (Gazis-Herman-Rothery) model for car following is applied and data have been collected by video cameras during 15?min time intervals in three different days. Analysis of 198 car-motorcycle and 374 car-car following observations has indicated that when a car driver follows a motorcycle, keeps a higher headway (about 10?m in the low speed) with a lower acceleration/deceleration in comparison with the situation in which car driver follow another one. It means that the behavior of the follower car driver would be more cautious compared to situations in which a car driver follows another one, especially in space headways <10?m. In addition to main findings of the paper for developing a more realistic simulation program, the paper also addresses that in cases when the required safe space between a car and a motorcycle would be endangered, a warning message could be generated for the car driver (by implementing an in-veh ITS technology) to warn driver about keeping a safe distance.     

Real-time implementation of a traction control algorithm on a scaled roller rig

Traction control is a very important aspect in railway vehicle dynamics. Its optimisation allows improvement of the performance of a locomotive by working close to the limit of adhesion. On the other hand, in case the adhesion limit is surpassed, the wheels are subjected to heavy wear and there is also a big risk that vibrations in the traction occur. Similar considerations can be made in the case of braking. The development and optimisation of a traction/braking control algorithm is a complex activity, because it is usually performed on a real vehicle on the track, where many uncertainties are present due to environmental conditions and vehicle characteristics. This work shows the use of a scaled roller rig to develop and optimise a traction control algorithm on a single wheelset. Measurements performed on the wheelset are used to estimate the optimal adhesion forces by means of a wheel/rail contact algorithm executed in real time. This allows application of the optimal adhesion force.     

Les systèmes de vélos en libre-service expliquent-ils le retour du vélo en ville ?

Many French and European cities have developed a bike sharing system since 2005. This policy may be explained in a great part by the success of the Velo??v in Lyon, which contributed to improve the image of cycling in the city. If bicycles, however, appear to find a new place in the city, one can wonder whether this is really due to bike sharing systems? What are the real uses of bicycles in contemporary cities, with or without such a system? To answer these questions, the paper starts with a literature review on bicycle in the city, to draw lessons from recent experiences of bike sharing systems. It then discusses the two cases of Lyon and Lille, which never had a bike sharing system on its own. The evolution of bicycle use is measured with a comparison of household transportation surveys in Lyon (1995 and 1998) and Lille (1998 and 2006). In both cities, the analysis reveals a rise in the proportion of healthiest citizens among urban bikers, as well as a return of bikes in dense areas. Bike sharing systems are part of such tendencies. They support them, but should not become a panacea for policies supporting bike use in the city.     

On the Performance Capabilities of Active Automobile Suspension Systems of Limited Bandwidth

Using methods established in earlier work, calculations are carried out to reveal the influence of actuator bandwidth on the performance capabilities of a class of active suspension system for automobiles. The suspension consists of an actuator in series with a spring, the combination being in parallel with a passive damper, and the system is modelled as a single wheel station traversing a random road. The results indicate that a system with a 3 Hz bandwidth actuator and variable damping will have excellent ride performance qualities over a wide range of road roughness conditions. Since such a system can be expected to be easily adaptable to the running conditions, to provide good static and dynamic attitude control, to be capable of contributing to good steering control responses and to be inexpensive in terms of capital and energy consumption costs compared with most of the active systems which have previously been discussed, it is suggested that it is a prime candidate for further study and practical development.     

Factors influencing crash involvement during early years of owning a new vehicle

Though automobile manufacturers are investing efforts to make newer vehicles safer to drive, an element of uncertainty with the new vehicle seems to persist with the drivers during the early years of ownership. This could be due to a lack of familiarity of the vehicle's power, dimensions or available technologies/features. While the uncertainty in itself is a potential cause of a crash, it is important for the policy-makers, practitioners, and automobile manufacturers to understand the factors that could further aggravate the problem. This research focuses on identifying the factors influencing the likelihood of getting involved in a crash and its severity when driving a new vehicle. Crash data for North Carolina for the years 2013 to 2018 (six years) was used develop partial proportionality odds models, compute the odds ratios, analyze the effects of explanatory variables, and identify factors influencing crashes by the age of the vehicle. The likelihood of getting involved in a severe or moderate injury crash when driving a new vehicle is less for drivers in the age group ≤19 years. Erratic driving behavior (like making wide turns, weaving and swerving in traffic, driving with headlights off, driving on center-line or lane-line, etc.) and speeding increase the risk of getting involved in a moderate injury crash when driving a new vehicle. Likewise, the odds of getting involved in a crash are high on weekends and in adverse weather conditions when driving a new vehicle. They are higher when driving a new motorcycle, heavy vehicle or farm machinery. The findings help policy-makers and practitioners formulate strategies to educate drivers on factors influencing crash risk when driving a new vehicle. Further, automobile manufacturers can establish guidance programs and documentation that explain what to expect when buying and driving a new vehicle.     

Using machine leaning techniques for evaluation of motorcycle injury severity

There is a growing interest in the application of the machine learning techniques in predicting the motorcycle crash severity. This is partly due to a progress in autonomous vehicles technology, and machine learning technique, which as a main component of autonomous vehicle could be implemented for traffic safety enhancement. Wyoming's motorcycle crash fatalities constitute a concern since the count of riders being killed in motorcycle crashes in 2014 was 11% of the total road fatalities in the state. The first step of crash reduction could be achieved through identification of contributory factors to crashes. This could be accomplished by using a right model with high accuracy in predicting crashes. Thus, this study adopted random forest, support vector machine, multivariate adaptive regression splines and binary logistic regression techniques to predict the injury severity outcomes of motorcycle crashes. Even though researchers applied all the aforementioned techniques to model motorcycle injury severities, a comparative analysis to assess the predictive power of such modeling frameworks is limited. Hence, this study contributes to the road safety literature by comparing the performance of the discussed techniques. In this study, Wyoming's motorcycle crash injury severities are modeled as functions of the characteristics that give rise to crashes. Before conducting any analyses, feature reduction was used to identify a best number of predictors to be included in the model. Also to have an unbiased estimation of the performance of different machine learning techniques, 5-fold cross-validation was used for model performance evaluation. Two measure, Area under the curve (AUC), and confusion matrix were used to compare different models' performance. The machine learning results indicate that random forest model outperformed the other models with the least misclassification and higher AUC. It was also revealed that a dichotomous response variable, with fatality and incapacitation injury in one category, along with all other categories in another group would result in a lower misclassification rate than a polychotomous response variable. This might result from the nature of motorcycle crashes, lacking a protection compared with passenger cars, preventing machine learning technique to get trained properly. Moreover, the most important variables identified by the random forest model are those related to the operating speed, resentful other party, traffic volume, truck traffic volume, riding under the influence, horizontal curvature, wide roadway with more than two lanes and rider's age.     

OH-radical behavior of unsteady lifted flame based on instantaneous change of the equivalence ratio

In an earlier study, the current authors showed that an unsteady-state lifted flame generated by an equivalence ratio conversion system for a given fuel, was similar to a steady-state lifted flame in terms of the change characteristics from a premixed flame to a critical flame and then to a triple flame with a diffusion flame positioned in the middle according to the concentration difference. Therefore, this study used an OH-PLIF method to investigate the characteristics of a steady-state lifted flame and an unsteady-state lifted flame created under conditions identical to the flames in the preceding study. PLIF (Planar laser induced fluorescence) is practically effective for visualizing the concentration fields within a flame. The resulting OH-radical measurements showed that an unsteady-state lifted flame created under the specific conditions used in this study showed similar tendencies in terms of OH-radical distribution, fluorescence intensity, and liftoff height, to a steady-state lifted flame, thereby confirming that the behavior of an unsteady-state lifted flame can be effectively predicted based on the behavior of a steady-state lifted flame.     

A list of accident scenarios for three legs skewed intersections

The term ‘scenario’ is used in the safety field to designate a prototype or a model of an accident process characterised by chains of facts, actions, causal relations and consequences in terms of damage to people and property. The prototypical scenarios, properly realized, provide a basis on which to consider the action to be taken, but also a concrete backup for accident information for use in information campaigns or training. The objective of this study is to define the prototypical accident scenarios for a particular configuration of road intersection: the skewed intersection. Limited sight distance at skewed intersections leads to safety issues. A non-skewed intersection provides the best operating conditions as drivers can easily sense the direction in which they are travelling, estimate the speeds of the opposing traffic and smoothly complete a maneuver in shorter time. In skewed intersections, instead, the ability of drivers to recognize any conflicting vehicles diminishes in comparison to right-angle intersections. The logical-deductive approach used in this paper for the determination of accident scenarios is based on an analysis of a large database of incidents, which occurred on several roads in eastern Sicily on 35 skewed intersections at three-legs. The skew angle of the minor leg of all the intersections studied is between 15° and 20°. This research allowed to develop accident scenarios related to particular configurations of intersections, compatible with the Italian rules. Prototypical scenarios are constructed using samples of accidents occurring on a particular type of study area, especially when they are based on files from in-depth investigations. The method used is an inductive approach, based on an examination of each case, grouping together similar cases and building a prototypical scenario using this case grouping. From the in-depth analysis of database accidents 9 prototypical accident scenarios have been identified for the skewed intersections.     

Integrated approach to an optimal automotive timing chain system design

Ensuring engine efficiency is a crucial issue for automotive manufacturers. Several manufacturers focus on reducing the time taken to develop and introduce brand new vehicles to the market. Thus, a synergic approach including various simulations is generally adopted to achieve a development schedule and to reduce the cost of physical tests. This study involved proposing a design process that is very useful in the preliminary development stage through effective support from simulations. This type of simulation-based design process is effective in developing timing chain drives; the use of this process, based on results from multiple trials, showed improvements in performance including low friction and vibration, improved durability, and cost-effective part design when compared to conventional processes. This study proposes an integrated approach to the preliminary design of an automotive timing chain system. The approach involves structural and dynamic analyses. The details of the design process are described by using the case of a virtual engine. This study conducted and summarized a dynamic and structural analysis as well as topological optimization to describe a process to obtain optimal results. The results of this study indicated the following improvements in overall performance factors: 12.1 % improvement in transmission error, 10.1 % reduction in chain tension, 46 % reduction in tensioner arm weight, and 11 % reduction in transversal displacement.     

聚脲润滑脂在汽车行业的应用

聚脲润滑脂具有较宽的温度使用范围，优良的氧化安定性和胶体安定性，耐高温、耐腐蚀、抗水淋、抗不良介质的影响，尤其是在高温下具有较长的使用寿命，是一种多效、通用的高档润滑脂。介绍了该润滑脂在国外汽车行业的应用情况，指出，为适应我国汽车工业的发展，应大力发展和推广应用。