In the past decade, the development and the application of traffic micro-simulation to replicate real-world traffic behavior have become pervasive among traffic and transport researchers. The modeling of a driver's car-following behavior, which forms the fundamental component of traffic microsimulation, has meanwhile been an important research direction leading to the sophistication of traffic microsimulation. However, recent studies have pointed out that a driver's following behavior varies when the lead vehicle is a passenger car as opposed to a heavy vehicle. Nevertheless, existing models do not precisely address those differences. This oversight could diversely affect the accuracy of traffic microsimula-tions, particularly with the current trend of an increasing number of heavy vehicles in the traffic stream. A novel car-following model that considered the heterogeneity of lead vehicles was developed. Two types of lead vehicles were considered in this study: passenger cars and heavy vehicles. The model was developed on the basis of the local linear model tree approach. This approach is able to incorporate human perceptual imperfections into a car-following model. The input space is partitioned incrementally, and a linear model is developed for each locality (partition). The final output is calculated by the fuzzy combination of local models according to the validity function of each model. For training and testing purposes, two real-world data sets were obtained from a U.S. freeway under congested traffic conditions. The results showed very close agreement between the real data and the outputs of the proposed model.

关键词：汽车；车辆类型；模型

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Shared spaces are being implemented in many countries to deal with safety concerns and traffic flow problems on busy urban streets and street crossings. However, shared space concepts could not be tested before they were built because of the lack of a functioning microscopic shared space simulation. Lane-based car-following models, currently used in traffic simulation, cannot reproduce the high heterogeneity of a mixed traffic mode's nonchannelized flow. This paper's novel approach introduces an extended social force model for vehicles and pedestrians that incorporates social interactions between different modes of transport rather than following a purely rule-based approach. The calibration of such a microscopic traffic simulation model with real-world data from two shared space sites is presented. The simulation can reproduce real-life shared space behavior by comparing it with trajectory and interaction data collected at implemented shared space road designs.

关键词：汽车；仿真系统；模拟比较

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报告从宏观政策环境、地方政策动态、竞争对手情报、产品与技术创新等几个方面进行了分析及评论。

关键词：宏观政策环境；地方政策动态；竞争对手情报；产品与技术创新

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This report summarizes key trends in carbon dioxide (CO2) emissions, fuel economy, and CO2- and fuel economy-related technology for gasoline- and diesel-fueled personal vehicles sold in the United States, from model years (MY) 1975 through 2012. Personal vehicles are those vehicles that EPA classifies as cars, light-duty trucks, or medium-duty passenger vehicles. The data in this report cover the MY 1975-2012 timeframe, supersede the data in previous reports in this series, and, for many important reasons, should not be compared with data from previous years editions of this report. Most CO2 emissions and fuel economy values in this report have been adjusted to reflect 'real world' consumer performance and therefore are not comparable to CO2 emissions and fuel economy standards.

关键词：汽车；轻型汽车技术；二氧化碳

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This paper introduces the effect of track wheel in rolling test of railway vehicle and puts forward a method of moment of inertia check based on inertia matching. According to coupled vibration between track wheel and wheel of car, normal modal analysis was proposed in this paper using FEM of PATRAN/NA-STRAN. Through analyzing, the result of first 10-order model was obtained. The analysis shows that the first inherent vibration frequency is 12.634 Hz. In this frequency and corresponding speed of 257 km/h of railway vehicle in the rolling test, the coupled vibration occurred between track wheel and wheel. During the test, avoiding running in 257 km/h for a long time will be useful for test precision.

关键词：汽车；模态分析；履带

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In natural traffic flow, the information from preceding vehicles predominantly determines driver behavior. With connected vehicle technologies, drivers can receive information from both preceding and following vehicles. This information creates new opportunities for vehicle coordination and control at the microscopic level on the basis of bidirectional information. Although bidirectional car-following models have been studied since the 1960s, most existing car-following models, especially those used by adaptive cruise control technologies, are still forward-only car-following models. This paper serves as a first step toward the use of bidirectional car-following models for microscopic vehicle coordination and control. The focus is on the study of the models' general control characteristics and impact on traffic flow stability. A general bidirectional control framework is proposed to convert any car-following model into its bidirectional form. Four representative General Motors and optimal velocity car-following models are reformulated and calibrated against field vehicle trajectory data collected in the next-generation simulation program (NGSIM). The bidirectional control characteristics of the selected models were evaluated by tuning of the percentage of backward information considered in the final car-following decision. The evaluation uses forward versus backward acceleration diagrams and a ring road stability analysis of equilibrium states obtained from NGSIM data. The results indicate that the increase in the contribution of backward information may help alleviate traffic congestion and stabilize traffic flow. An operating range of the backward information contribution of between 5% and 20% is recommended to ensure that the resulting models are still physical and realistic for both free-flow and congestion situations.

关键词：汽车；通用汽车；安全

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The Michigan State Police Vehicle Test Team is pleased to present the results of the 2013 model year Police Vehicle Evaluation. This year we tested thirteen vehicles in total, and four motorcycles. All of the cars were tested with a clean roof (no overhead light or light bar) and without A pillar mount spotlights. We believe this is the best way to ensure all of the vehicles are tested on an equal basis. Remember that once overhead lights, spotlights, radio antennas, sirens, and other emergency equipment are installed, overall performance may be somewhat lower than we report. Each vehicle was tested with the tires that are available as original equipment on the production model. Specific tire information for each vehicle is available in the Vehicle Description portion of this report. All vehicles listed in this report were equipped with electronic speed limiters. Motorcycles were tested with equipment installed as provided by their respective manufacturer. Harley-Davidson chose to test their bikes with minimal equipment. BMW, and Victory chose to test their bikes with the majority of the equipment installed.

关键词：汽车；警车；交通安全

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In this paper, fisher discriminant analysis (FDA) is used for fault isolation and diagnosis in rail vehicle suspension systems. The suspension systems are equipped with acceleration sensors in the corners of the car body and the two bogies. The faults considered are the lateral damper faults and the lateral spring faults in suspension systems. FDA provides an optimal projection space on the basis of the training data including the fault data and normal data to classify the test data. A vehicle model is built by SIMPACK/MATLAB software with real parameters to obtain the simulation data and the effectiveness of the proposed method is demonstrated by simulation.

关键词：汽车；故障检测；判别分析

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We set up one cylinder of CNG engine by using GT-Power software and the compression ratio and the knock are studied.The conclusions are as follows:when the compression ratio increases,the rate of pressure rise of acute burning period increases; The maximum cylinder pressure increases;The maximum temperature decreased slightly and after burning period the temperature increases;The critical knocking compression ratio appears at the full load of 4000rpm conditions; If we only consider it knocking or not,the engine compression ratios can change from 10 to 11.

关键词：汽车；发动机；仿真分析

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OH Laser Induced Fluorescence (LIF) and picosecond (ps), broadband Coherent Anti-Stokes Raman Spectroscopy (CARS) are used for time-resolved temperature and time-resolved, absolute OH number density measurements in lean H2-air, CH4-air, C2H4-air, and C3H8-air mixtures in a nanosecond (ns) pulse discharge cell/plasma flow reactor. The premixed fuel air flow in the reactor, initially at T0 = 500 K and P = 100 torr, is excited by a repetitive ns pulse discharge in a plane-to-plane geometry (peak voltage 28 kV, discharge gap 10 mm, estimated pulse energy 1.25 mJ/pulse), operated in burst mode at 10 kHz pulse repetition rate. In most measurements, burst duration is limited to 50 pulses, to preclude plasma-assisted ignition. The discharge uniformity in air and fuel air flows is verified using sub-ns-gated images (employing an intensified charge-coupled device camera). Temperatures measured at the end of the discharge burst are in the range of T = 550 600 K, using both OH LIF and CARS, and remain essentially unchanged for up to 10 ms after the burst. Time-resolved temperature measured by CARS during plasmaassisted ignition of H2-air is in good agreement with kinetic model predictions. Based on CARS measurement, vibrational nonequilibrium is not a significant factor at the present conditions. Time-resolved, absolute OH number density, measured after the discharge burst, demonstrates that OH concentration in C2H4-air, C3H8-air, and CH4 is highest in lean mixtures. In H2-air, OH concentration is nearly independent of the equivalence ratio. In C2H4-air and C3H8-air, unlike in CH4- air and in H2-air, transient OH-concentration overshoot after the discharge is detected. In C2H4-air and C3H8-air, OH decays after the discharge on the time scale of 0.02 0.1 ms, suggesting little accumulation during the burst of pulses repeated at 10 kHz. In CH4-air and H2-air, OH concentration decays within 0.1 1.0 ms and 0.5 1.0 ms, respectively, showing that it may accumulate during the burst.

关键词：汽车；燃料；能源

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