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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In this research, the feasibility of using mobile traffic sensors for binary vehicle classification on arterial roads is investigated. Features (e.g. speed related, acceleration/deceleration related, etc.) are extracted from vehicle traces (passenger cars, trucks) collected from real world arterial roads. Machine learning techniques such as support vector machines (SVM) are developed to distinguish passenger cars from trucks using these features. To address privacy concerns, classification is conducted using long vehicle traces and short vehicle traces separately. For classification using long traces, the proportions of accelerations and decelerations larger than 1mpss and the standard deviations of accelerations and decelerations are the most effective features. By classifying general trucks from passenger cars, the average misclassification rate for the best 4-feature SVM model is about 1.6% for the training data, and 4.2% for the testing data. For classification using short traces, it is necessary to define multiple types of traces and analyze them case-by-case. It was found that particularly for the turning movement traces, features such as average speed, standard deviation of speed, maximum acceleration/deceleration and standard deviation of acceleration/deceleration are fairly effective to classify vehicles. The misclassification rate for the best SVM classifier using short traces is about 14.8% for the stop-and-go traffic, and 15.6% for the non-stopped traffic.

关键词：汽车；汽车分类；传感器

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An application of the basic results of deterministic network calculus theory to road traffic flow theory is presented. Network calculus is a theory based on min-plus algebra. This calculus uses algebraic techniques to compute performance bounds in communication networks, such as maximum end-to-end delays and backlogs. The objective of this paper is to investigate the application of those techniques for determining performance bounds on road networks, such as upper bounds for travel times. A traffic model is proposed for cars moving in a single-lane ring road without passing. The model is compatible with network calculus theory and permits derivation of an upper bound of the travel time of cars on the road. An approach for extending the model to calculate upper bounds for the travel times of cars on paths passing through intersections in a whole network is also proposed.

关键词：汽车；交通网络；微积分

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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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Electric vehicles will longitudinally vibrate obviously under acceleration and regenerative braking conditions (because of torsional vibration of the electric vehicle powertrain).This paper includes models of motor rotor,gear reducer and differential assembly,half shafts,tire and body and nonlinear powertrain dynamic model in consideration of gear backlash and frictional characteristics between tire and ground.Real car tests confirm that it is correct under acceleration conditions.Then a two mass-spring damper linear model which is simplified from the nonlinear powertrain dynamic model is proposed to design torsional vibration control algorithm based on state feedback.The simulation results show that the algorithm can actively eliminate torsional vibration.

关键词：汽车；电动汽车；动力系统

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Improvised explosive devices and car bombs have long been identified as threats to U.S. Army personnel deployed in Iraq and Afghanistan. They have gained considerable attention and notoriety, even infamy, among our troops, who have had to learn the appropriate responses and countermeasures to contend with the fielding of these systems against them. Far less recognized is the fact that a similar threat embodied in car bombs has emerged much closer to our homeland within Mexico. Since mid-2010, cartel car bombings have taken place in a country on our southern border and have been targeted against both the forces of opposing cartels and those belonging to Mexican military and law enforcement agencies. With the election of the new presidential Institutional Revolutionary Party (PRI) administration in July 2012, these car bombings have ceased altogether after rapidly escalating in their levels of employment. Whether this was a response to the expected shift in countercartel policies from the National Action Party (PAN) to the PRI administration that began in December 2012, simply a strategic pause of some sort, or an outcome of another casual factor is unknown. What is important is that the use of car bombs in Mexico by the cartels has the potential to threaten U.S. agents, facilities, and interests in that nation and could also conceivably spread to our border cities though this would appear to be a very unlikely possibility based on the use of car bomb trends and analysis presented in this Paper. The authors of this Letort Paper, Dr. Robert Bunker and John Sullivan, draw upon their wealth of knowledge and expertise pertaining to the Mexican cartels and organized crime and, interestingly, is derived from their long-standing counterterrorism backgrounds with regard to suicide bombing and active aggressor response.

关键词：汽车；汽车爆炸；交通安全

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关键词：汽车；交叉研究；交通安全

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It is very important to obtain an ideal basic shape with optimal aerody namic characteristics in the auto-body styling design based on the whole shape optimization.Through obtaining the solutions for conflict problem in the auto-body styling aerodynamic design cooperating extension engineering, a variable cross-section method based on aero dynamic theoretical model to obtain ideal basic shape for car body is proposed.A theory model based on aerodynamics is developed.In addition, a generation method for a series of ideal basic bodies with favorable aerodynamic characteristics is developed, which enables the generation of these basic bodies by a variable cross-section method.This method is finally realized and it is shown in the evaluation that it is a new way for the auto-body styling design based on whole shape optimization.

关键词：汽车；车身形状；截面

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A 37-year-old diesel mechanic employed by a railroad transportation company died when his loaded utility truck collided with the rear of a semi-trailer on a four-lane interstate highway. The mechanic was driving at highway speed during daylight hours when he failed to stop in time and struck the semi, which was moving slowly in traffic that had backed up due to a car fire two miles downstream. There was severe damage to the mechanic's truck, with underside of the cab and intrusion up to the right rear tires of the trailer ahead. The force of the collision caused a chain reaction, pushing the struck tractor-trailer forward into a second tractor-trailer that had stopped in backed up traffic. Fire and rescue responders arrived from the nearby town located four miles away. The mechanic, who was wearing a safety belt, suffered blunt force trauma as a result of the collision and was pronounced deceased at the scene. He was extricated by mechanical means from the truck cab and was found holding a cell phone. Law enforcement officers' examination of the phone activity revealed the mechanic had exchanged several voice/text messages prior to the crash and was initiating a voice/text message application at the time of the collision. The driver's failure to notice the tractor trailer ahead and stop in time was attributed to texting. Drivers of the other two vehicles were not severely injured.

关键词：汽车；交通安全；机动车事故

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This paper presents an analysis of the degree of willingness to change from motorized travel modes to walking or cycling. The aim of the analysis is to reduce uncertainty between stated willingness to change and real shifts from car or transit to nonmotorized transportation modes. Data were collected in the city of Valencia, Spain, through a novel data collection effort based on multiple survey methods. Respondents traveling by car or transit were asked about their willingness to change to walking or cycling under the implementation of improvement measures to be selected. Then a hypothetical scenario was presented to respondents who stated a willingness to change; in the scenario, the previously selected measures were implemented and respondents were supposed to be cycling or walking. In addition, the costs of their usual travel mode were gradually reduced until they gave up cycling or walking. Those who decided to keep on walking or cycling were assumed to have a strong willingness to change. A statistical analysis performed with Heckman's sample selection model permitted identification of demographic, socioeconomic, and travel-related factors influencing the degree of willingness to change. Results revealed that car users presented a stronger willingness to switch to walking or cycling than transit users. In addition, older respondents showed a stronger willingness to change to both walking and cycling. Work- and school-related journeys were less associated with walking than noncommuting journeys, but they were more related to cycling. Policy implications of the results are highlighted.

关键词：汽车；意愿评估；模式选择

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