企业与市场

正斯堪尼亚全新Streamline国内多地同步上市2014年2月28日,斯堪尼亚全新Streamline在深圳、北京、上海等国内7个城市同步上市,来自全国各地的运输行业从业者共同见证。换代后的斯堪尼亚全新Streamline系列拥有更加卓越的燃油经济性(提升7%),拥有最高的出勤率和优异的性能。此次全国范围的上市推广活动,内容丰富多彩。现场不仅举行了斯堪尼亚全新Streamline的车辆交付仪式,与此同时,还包括"行驶里程超过225万km车主现场授勋","新老Streamline同台亮相"等环节,全面     

改变的不只是面孔——斯堪尼亚全新Streamline广州首秀

近日,斯堪尼亚在广州发布了全新Streamline长途运输车系列,该系列产品具有出色的扭矩功率比,在考虑尿素使用成本的情况下,普通驾驶员的燃油经济性提升率则最高可达7%。同时,由于采用了模块化设计,全新Streamline系列能够在斯堪尼亚所有服务网络得到相关服务,该系列将于2014年初在中国市场正式销售。     

斯堪尼亚全新Streamline在国内七城市同步上市

<正>2月28日,斯堪尼亚全新Streamline在深圳、北京、上海等国内7个城市同步上市,来自全国各地的运输行业引领者共同见证了这一盛事。换代后的斯堪尼亚全新Streamline系列拥有更加卓越的燃油经济性,最高的出勤率和优异的性能。     

斯堪尼亚全新Streamline系列登陆中国市场

近日，斯堪尼亚揭开专为中国市场精心配置的全新Streamline长途运输车系列的神秘面纱，树立燃油经济性新标准。斯堪尼亚曾推出的欧Ⅱ系列是节能方面的市场领先产品，而与之相比。     

Streamline,既是传承,也是创新——访斯堪尼亚销售(中国)有限公司售前总监崔蕊

近日,斯堪尼亚(中国)售前总监崔蕊向本刊记者进一步阐释了全新Streamline系列在配置、设计及性能方面的改变。全新Streamline不仅是对第一代的传承,也是对斯堪尼亚持续改进产品理念的展示。同时,针对中国市场,全新Streamline也做出了个性化的创新。     

镁合金压铸技术在高性能发动机油底壳上的应用

随着对汽车燃油经济性的要求不断提高，对车辆轻量化的需求也进一步提高，能减轻零部件质量的镁合金压铸技术已引起广泛关注。介绍将镁合金压铸技术应用于发动机油底壳时的基本设计理念，以及在可靠性、可铸性方面的技术开发概况，同时也介绍了一些实际应用成果。     

整车质量对行驶阻力和燃油消耗量的影响分析

目前汽车轻量化已成为国内外汽车行业的研究热点,降低整车质量可有效减少车辆行驶阻力和整车燃油消耗量。文中通过调整整车质量进行道路阻力功率滑行来获得整车实际行驶阻力,在底盘测功机上进行Ⅰ型排放试验,测试整车燃油消耗量;同时采用法规推荐阻力测试整车燃油消耗量,进一步分析车辆在不同加载方式下(滑行法和查表法)整车质量对车辆行驶阻力和整车燃油消耗量的影响。     

车型北京现代朗动轿车

故障现象车辆加油后，燃油表无显示。检查分析验证故障现象，发现车辆加满油后，燃油表显示燃油箱内无燃油，仪表盘上燃油量过少报警指示灯处于报警状态。根据故障现象分析，导致上述故障的原因有以下几个方面：相关线路或导线连接器故障；燃油油量传感器故障；燃油表故障。检测燃油油量传感器在各位置下的电阻，均在正常范围，说明燃油油量传感器无异常。     

车辆电能精确管理技术

精确地控制车辆蓄电池的充放电系统,能够显著地提高车辆的燃油经济性、减小车辆的整备质量、降低废气排放量等。可以预料,车辆蓄电池充电系统精确控制技术在不久的将来会得到普及。     

轮胎也节油--Michelin节油型轮胎实测

轮胎作为汽车的关键承载部件之一,具有承受车辆负荷、向路面传递驱动力和制动力等作用,对汽车而言,这些功能必不可少。同时,轮胎也能影响汽车的燃油经济性、操纵性和安全性。轮胎的质量、安装及使用情况直接影响车辆的燃油消耗量。阻止车辆行驶的力包括空气阻力、传动系阻力(内摩擦力)和轮胎滚动阻力,这些力都能加大载重车发动机的燃油消耗量。据统计,在无风平坦的路面上行驶,轮胎的滚动阻力占车辆行驶总阻力的60%,毫无疑问,只有     

A new active variable stiffness suspension system using a nonlinear energy sink-based controller

This paper presents the active case of a variable stiffness suspension system. The central concept is based on a recently designed variable stiffness mechanism which consists of a horizontal control strut and a vertical strut. The horizontal strut is used to vary the load transfer ratio by actively controlling the location of the point of attachment of the vertical strut to the car body. The control algorithm, effected by a hydraulic actuator, uses the concept of nonlinear energy sink (NES) to effectively transfer the vibrational energy in the sprung mass to a control mass, thereby reducing the transfer of energy from road disturbance to the car body at a relatively lower cost compared to the traditional active suspension using the skyhook concept. The analyses and simulation results show that a better performance can be achieved by subjecting the point of attachment of a suspension system, to the chassis, to the influence of a horizontal NES system.     

汽车爆胎的原因及应对措施问题研究

近年来,我国汽车产销量直线上升,已超越美国成为世界第一大汽车消费市场,但随着汽车保有量的增长,汽车爆胎事故也在不断上升,已严重威胁人民群众的财产和生命安全,据公安部统计,高速公路70％的亡人交通事故是由于爆胎引起的,汽车时速在120公里发生爆胎,死亡率为100％.因此,如何预防和减少汽车爆胎,已经成为汽车安全的焦点话题,那么汽车爆胎的原因是什么呢？遇到爆胎怎么办呢？如何有效地预防汽车爆胎呢？     

Active Roll Mode Control Implementation on a Narrow Tilting Vehicle

This paper describes work carried out on the development of a narrow tilting vehicle at the University of Minnesota. The project had two objectives. One objective was to better understand the dynamics of two-passenger leaning vehicles. The other was to use this understanding to design and implement leaning control on such a vehicle. The desire was to make a tilting vehicle as easy, in some sense, to drive as a non-leaning vehicle. The scope of this work was fourfold. First, a model of such a system was developed and linearized to obtain a fourth-order linear model. Second, a tilt controller was designed to stabilize a tilting vehicle's unstable rolling mode. Third, the system and controller were simulated using both Simulink and a real time simulator written with Visual Basic. Fourth, and most importantly, an experimental vehicle was built and used for implementation. Comparisons were made between the simulated system and the experimental vehicle. This illustrated the limitations encountered in the simulations but also showed similarities that validated the model. Also, experimental results showed that the vehicle was stabilized well by the controller within the limitations of our hardware.     

Mitigating the effect of impact loading on a vehicle using an essentially nonlinear absorber

The aim of this study is to investigate the ability of an essentially nonlinear vibration absorber to mitigate the large accelerations transmitted to a passenger compartment of a vehicle which is subjected to shock-type transient loading at the chassis. For such problems, the induced vibration typically attains its maximum value shortly after the application of the loading; thus, it may be impossible to dissipate a major portion of the input energy prior to the occurrence of the peak response. Here, a class of absorbers possessing a form of discontinuous essential stiffness nonlinearity is employed to achieve the desired mitigation. In this paper, we apply a single vibro-impact (VI) absorber to the chassis and examine whether the resulting energy transfer mechanism is an effective way to reduce the peak value of the inertial force measured at the passenger compartment. The influence of the absorber parameters is first studied based on a practical impulsive force, and the optimal design of the absorber is then obtained. Next, an asymmetric clearance arrangement of the absorber is suggested to facilitate the mitigation. Finally, an impulsive acceleration excitation is applied to the system to examine the robustness and efficacy of the optimised absorber. Results of numerical simulations demonstrate that a properly designed VI absorber can significantly decrease the maximum inertial force at the passenger compartment, generated by external impulsive excitations.     

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.     

A study on a dynamic model of a vehicle simulator with 6 DOF for the Korean tilting train

This article presents a dynamic model of a railway vehicle for the development of a 6-DOF (degrees of freedom) tilting-train simulator. It will be used to verify the tilting-electronics and tilting-control algorithm that are to be applied to the Korean tilting train. It is composed of 6 electrically driven actuators, a track generation system, a graphic user interface, and a visualization system with a 1600-mm-diameter dome screen. Each system shares the data by means of Ethernet network in real time. In this study, a train model of 9-DOF with a force generation system to tilt the train body has been used. Dynamic analysis for the straight track running and curve negotiation of a railway vehicle can be performed in the model. A verification study for the application of the model to the simulator has been conducted on curving tracks with different radii.     

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.     

Simulation tool for optimization and performance prediction of a generic hybrid electric series powertrain

Hybrid and electric vehicles are taking an increasingly important slice of the market, gaining much interest from major car manufacturers which have decided to invest in this sector, taking as example the pioneers like Toyota. The key factor to hybrid and electric vehicle success is a good overall mileage achieved from the battery back or powertrain. The purpose of this work is to provide a support to design, testing, and development of such vehicles through the implementation of a mathematical model in order to simulate the operation and predict the performance of a generic ground vehicle equipped with either a purely electric or a hybrid-electric type powertrain. The model should enable the user to estimate the impact of various control strategies on mileage range, efficiency, energy consumption, etc. The model should also allow for a significant time to market reduction with all the related benefits in terms of cost etc. A validation is also provided, based on the application of this tool on a so-called micro-car (0.5t GVW class). Thanks to a joint research project with the manufacturer it has been possible to compare model results with real-world data directly obtained during road testing with the help of a data acquisition system.     

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.     

Optimization of the Lateral Stability of Rail Vehicles

Summary The lateral stability of a rail vehicle is optimized using a combination of multibody dynamics, sequential quadratic programming, and a genetic algorithm. Several steps are taken to validate this integrated approach and to show its effectiveness. First, a hand-derived solution to a 17 degree of freedom linear rail vehicle model is compared to the simulation results from the A'GEM multibody dynamics software. Second, the calculation of the ‘critical speed’ (above which a rail vehicle response becomes unstable) using sequential quadratic programming is validated for a specific example. In the process, the existence of sharply-discontinuous ‘cliffs’ in the plots of critical speed versus suspension stiffnesses are identified. These cliffs, which are due to switching of the least-damped mode in the system, greatly hinder the application of gradient-based optimization methods. Two methods that do not require gradient information, a genetic algorithm and the Nelder-Mead's Simplex algorithm, are used to optimize the critical speed. The two algorithms and their results are compared. In recognition of the cliff phenomenon, the definition of critical speed is generalized to make it a more practical measure of lateral stability.