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Technical Paper

A Comparison Study of Car-to-Pedestrian and Car-to-E-Bike Accidents: Data Source: The China In-Depth Accident Study (CIDAS)

2014-04-01
2014-01-0519
The aim of the study was to investigate the difference between car-to-e-bikes and car-to-pedestrian accidents. The China In-depth Accident Study (CIDAS) database was searched from 2011 to 2013 for pedestrians and e-bikes struck by car, van and SUV fronts, which resulted in 104 pedestrian and 85 e-bike cases where information was sufficient for in-depth analysis. Reconstruction by PC-Crash was performed for all of the sampled cases. Pre-crash parameters were calculated by a MATLAB code. Focus was on prototypical accident scenarios and causes; speed as well as possible prevention countermeasures. It has been shown that traffic light violations, road priority violations, and unsure safety (these situations included misjudgments, unpreparedness, proximity to other road users, inappropriate speeds, etc.…) are the main causes in both the VRU groups. Distinctions were found for aspects of car collision speed, accident scenario, distribution of head contact points and so on.
Technical Paper

Characteristics and Casualty Analysis of Two- Wheeler Accidents in China, Data Source: The China In-Depth Accident Study (CIDAS)

2018-04-03
2018-01-1052
The two-wheeler is a vehicle that runs on two wheels, which is classified as motorcycle, electric-bicycle, and bicycle in this research. China has the largest number of two-wheelers and relevant accidents in the world. The two-wheeler riders have a high level of vulnerability, creating a significant necessity to better understand the characteristics according to the road-user group. The objective of this paper is to study the characteristics and analyze the causes of two-wheeler accidents in China using the CIDAS (China In-Depth Accident Study) Database. 2012 cases of two-wheeler accidents with riders injured or dead were collected from the CIDAS Database from 5 cities (Changchun, Beijing, Weihai, Ningbo and Foshan) in China over a period of 5 years (2011.07-2016.06).
Technical Paper

Deterioration Characteristic of Catalyzed DPF Applied on Diesel Truck Durable Ageing

2018-09-10
2018-01-1701
In this paper, it was researched the degradation characteristics of catalytic performance of three kinds of DPFs (C1, C2 and C3, with precious metal concentrations being 15, 25 and 35 g/ft3 respectively) after diesel truck aging. It is found out that the crystallinity of three kinds of DPF samples (Used) in full vehicle aging was higher than that of fresh samples (Fresh) and aged samples (Aged) in the laboratory. Compared with Fresh samples, the concentration of Pt atom in precious metal on the surface of Aged and Used samples tends to decrease in most cases. Activities to CO and C3H8 of Aged and Used samples of three kinds of DPFs had all been degraded, and activity degradation showed a substantial correlation with concentration reduction rate of precious metal on the carrier surface. NO2 productivity of Used samples all rose. Crystallinity of DPF samples after full vehicle aging in Inlet, Middle and Outlet areas successively increased.
Technical Paper

Development of Fuel Consumption Test Method Standards for Heavy-Duty Commercial Vehicles in China

2011-09-13
2011-01-2292
To restrain the environmental and energy problems caused by oil consumption and improve fuel economy of heavy-duty commercial vehicles, China started developing relevant standards from 2008. This paper introduces the background and development of China's national standard “Fuel consumption test methods for heavy-duty commercial vehicles”, and mainly describes the test method schemes, driving cycle and weighting factors for calculating average fuel consumption of various vehicle categories. The standard applies to heavy-duty vehicles with the maximum design gross mass greater than 3500 kg, including semi-trailer tractors, common trucks, dump trucks, city buses and common buses. The standard adopts the C-WTVC driving cycle which is adjusted on the basis of the World Transient Vehicle Cycle[1, 2] and specifies weighting factors of urban, rural and motorway segments for different vehicle categories.
Technical Paper

Dynamic Correction Strategy for SOC Based on Discrete Sliding Mode Observer

2019-04-02
2019-01-1312
Battery state estimation is one of the most important decision parameters for lithium battery energy management. It plays an important role in improving battery energy utilization, ensuring battery safety and enhancing system reliability. This paper is proposed to provide a dynamic correction of SOC in the full working condition, including static condition and dynamic condition. Based on the Coulomb-counting method, the current SOC value of the battery is calculated. Under the static conditions, the open circuit voltage of the battery is used to directly collect the initial SOC. Under the dynamic working conditions, the open circuit voltage of the battery is estimated by the sliding mode observer. Based on the deviation between the calculated and estimated values of the open circuit voltage, the current coefficient of the Coulomb-counting method is dynamically corrected by PI strategy.
Technical Paper

Numerical Analysis of Underbody Diffusers with Different Angles and Channels

2019-04-02
2019-01-0668
The underbody diffusers are used widely in race cars to improve the flow field structure at the bottom of the car and provide enough downforce. In recent years, passenger cars have begun to use bottom diffuser to improve aerodynamic characteristics, so as to reduce drag and increase downforce. In this paper, the aerodynamic characteristics of the bus with different underbody diffuser angles and channel numbers are studied by numerical simulation analysis. Firstly, the aerodynamics of the bus under different diffuser inlet and outlet angles are studied, and then an optimal inlet and outlet angle is determined based on the simulation results. Then, using this angle as a constant, the 2, 3, and 4 channel numbers were chosen as the diffuser channel variables to study the influence of the multiple-channel diffusers on the aerodynamic drag of the vehicle.
Technical Paper

Passenger Car 25% Overlapping Collision Accident Study Base on CIDAS

2018-08-07
2018-01-1595
With the development of vehicle technologies, vehicle safety is much better than before, many companies put research focus on harder accident scenarios. The 25% overlapping collision is considered as one type of most dangerous collision, this paper study this type accidents base on CIDAS database. Paper showed 7 scenarios appeared frequency in China, 11, 12, 1 o’clock are main impact direction. High way and freeway are the main places, and the head, thorax and lower extremities were the main sites of injury.
Technical Paper

Research on Dynamic Load of Belgian Event Based on Virtual Proving Ground

2019-04-02
2019-01-0170
The fatigue load spectrum of the physical proving ground is the necessary input for fatigue life analysis of vehicle parts and components. It is usually obtained by Road Load Data Acquisition (RLDA) and loads decomposition using multi-body dynamics tools. Virtual Proving Ground (VPG) methodology is gradually replacing this technical strategy. The belgian road is the typical event in durability test, in this paper, the flexible body and FTire model are applied to the vehicle multi-body dynamics model in order to improve the simulation accuracy. The result shows that all the wheel center force, shock absorber displacement and axial force acquired by VPG simulation have excellent correlation with real vehicle measured data. It is also proved that the virtual proving ground technology is a reliable and effective method to obtain the fatigue load spectrum in the early stage of development.
Technical Paper

Research on Intelligent Vehicle Index and Evaluation Method

2018-08-07
2018-01-1634
As automobiles are gradually transforming from independent mechanical units to network nodes with intelligent and networked functions, the functions and performance evaluation of intelligent vehicles is facing the new challenges. At present, China has initially classified the level of intelligent vehicles on the basis of SAE, but has not yet formed a scientific, rigorous and comprehensive evaluation system. Therefore, this paper proposes the detailed intelligent evaluation ideas of intelligent vehicles in different levels from 0 to 5 and sets up a "Trinity" evaluation system covering professional evaluation, practical evaluation and market evaluation. Then, with the development progress of intelligent vehicles, we will set up the hierarchical structure of evaluation indicators basing on automated intelligence and connected intelligence.
Technical Paper

Research on the Development of China Intelligent Connected Vehicle Test and Demonstration Zone

2019-10-22
2019-01-2612
As an integrated product of the development of automobile, electronics, communication, internet and transportation, intelligent connected vehicle industrial development is gradually moving from technology research and development to the stage of mass production. In the commercialization process of industry, test evaluation and demonstration operation are the key links, which has been highly valued by the national ministry, local government and enterprise. In this context, this paper firstly summarizes the development status of China intelligent connected vehicle test and demonstration zone, and clarifies the institutions, operating entities and functional positioning of different test demonstration zone. Secondly, it analyzes the professional technical schemes such as the overall functional planning, the design of the automatic driving and network application scenarios, which may provide reference for the improvement and planning design of the test demonstration zone.
Technical Paper

The Development of an Advanced Vehicle Control Platform for Pure Electric Vehicles

2015-04-14
2015-01-0229
Pure electric vehicles are recognized as one of the most important new energy vehicle types to meet the increasingly stringent standards in energy saving and environment protection. To meet the control demands, China Automotive Technology & Research Center(CATARC) plan to develop an advanced Vehicle Control Platform(VCP) for pure electric vehicles. The developed VCP is well structured on both hardware and software and can be adapted to different pure electric vehicles easily. This paper describes the design of the hardware, the software architecture, the base software and the control strategy applied in the VCP in detail. A matching method is proposed to configure the VCP to a real VCU for the specific application by modifying the hardware channel definition and the control parameters. The paper shows successful application of the VCP on several types of pure electric vehicles.
Technical Paper

The Synthetic 3DOF Wheel Force for Passenger Vehicle Based on Predicted Frequency Response Function Model

2018-04-03
2018-01-0123
To determine the vehicle chassis requirements, wheel force transducer (WFT) have been the best option when it is being used in targeting customer correlation or determining the effective use of the proving ground. However, using wheel force transducer in customer correlation fleet test is often unfeasible due to the huge cost and low practicability. As a result, engineers have to choose other transducer measures. This paper describes an effective approach of wheel force prediction by using the frequency response function (FRF) model of vehicle dynamic system. A vehicle system linear modelling technique is used. For the system identification of FRF, the acceleration and wheel force time history data, as system input and output, are collected from an instrumented passenger car as it traverses in different real-world proving ground surfaces. The obtained FRF represents the complex suspension mechanical model. Once the FRF is calculated, the predicted force signal can be implemented.
Technical Paper

Typical Pedestrian Accident Scenarios in China and Crash Severity Mitigation by Autonomous Emergency Braking Systems

2015-04-14
2015-01-1464
In China, nearly 25% of traffic fatalities are pedestrians. To avoid those fatalities in the future, rapid development of countermeasures within both passive and active safety is under way, one of which is autonomous braking to avoid pedestrian crashes. The objective of this work was to describe typical accident scenarios for pedestrian accidents in China. In-depth accident analysis was conducted to support development of test procedures for assessing Autonomous Emergency Braking (AEB) systems. Beyond that, this study also aims for estimating the mitigation of potential crash severity by AEB systems. The China In-depth Accident Study (CIDAS) database was searched from 2011 to 2014 for pedestrian accidents. A total of 358 pedestrian accidents were collected from the on-site in-depth investigation in the first phase of CIDAS project (2011-2014).
Technical Paper

Voltage and Voltage Consistency Attenuation Law of the Fuel Cell Stack Based on the Durability Cycle Condition

2019-04-02
2019-01-0386
Based on the durability cycle test of fuel cell stack and the characteristics of cyclic working conditions, this paper defines the characteristic current point and studies the attenuation rule of the fuel cell stack voltage over time under the characteristic current point. The results show that the voltage of the fuel cell stack appears to be linear downward under the characteristic current point. and the voltage attenuation rate of the fuel cell stack increases quadratically with the increase of the current density in addition to the open-circuit voltage point. Then the coefficient of variation is introduced in statistics as the index to characterize the voltage consistency attenuation of the fuel cell stack, and its variation rule is explored. The results show that the voltage consistency of vehicle fuel cell stack decreases seriously with the increase of running time under the condition of durable cycling.
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