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• 2012, Vol. 3 No. 1
  Published on:25 March 2012 Previous issue    Next issue
  Progress & Prospects

  Reducing Real-World Automotive Emissions in Major Cities in China

  Reggie ZHAN

  2012, 3(1):  1-11.  doi:10.3969/j.issn.1674-8484.2012.01.001

  Abstract ( 2410 )   PDF (1914KB) ( 2828 )  

  Air pollution has become a severe concern in the major cities in China. This paper reviews the onroad
  and off-road emission regulations in the United States and European Union, as well as the advanced
  emission aftertreatment technologies. A few key factors were identified that substantially influence the realworld
  engine and vehicle emission reduction in the major cities in China. Recommendations were made to
  implement a highly integrated system approach, involving fuel and lubricant qualities, engine and aftertreatment
  technologies, as well as emission standard establishment and implementation. With the recently passed
  greenhouse gas (GHG) regulations in the United States and European Union, as well as the fuel economy rules
  in the United States, GHG and fuel economy will be the key focus in engine and vehicle technology development
  in the future, while the very stringent emission regulations must still be met without compromise.

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  Automotive Safety

  Wrap-type safety belt for protecting pregnant occupants from vehicle collision

  CAO Libo, XIAO Huiqing, JIANG An

  2012, 3(1):  12-18.  doi:10.3969/j.issn.1674-8484.2012.01.002

  Abstract ( 2120 )   PDF (2367KB) ( 1769 )  

  A wrap-type safety belt for pregnant occupants was developed to protect the pregnant occupant
  and the fetus seated in the frontal passenger seat in a vehicle crash. This belt includes the femur belts and can
  be used with traditional three-point belt. The finite element model for 30-week-pregnant uterus was established
  and contrasted based on the uterus structure and injury mechanism of fetus.The validity of the model for the
  pregnant occupant was also verified which includes this uterus model. The situations that the pregnant occupant
  wears the belt or not were simulated under the frontal impact conditions at different impact speeds.The results
  show that the wrap-type safety belt can reduce the uterine strain at the uterus placental interface (UPI) and the
  possibility of placental abruption in a frontal impact event, but that the belt should be worn to fit the abdomen of
  pregnant occupant with a slight clearance rather than very tightly.

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  Scenario Design and Driving Simulation Experiment of Vehicle-to-Pedestrain Accidents Based on Real Accident Data

  YUAN Quan, HU Mengxia, LI Yibing

  2012, 3(1):  19-25.  doi:10.3969/j.issn.1674-8484.2012.01.003

  Abstract ( 2158 )   PDF (1625KB) ( 2207 )  

  A driving simulation test was performed to obtain the driver’s emergency operating data as a
  reference for accident reconstruction. In-depth human-vehicle-road data from 88 accident cases were analyzed
  according to the experiences of traffic accident investigation, based on the real data source of vehicleto-
  pedestrian accidents in Beijing. The typical accident modality, impact character and road scene were
  summarized, including the motion status of the vehicle and pedestrian, the type and characteristics of roads,
  and the emergency behavior of drivers to build a virtual reality emulation of vehicle-to-pedestrian accidents.
  The trigger experiments of human-vehicle conflicts were exerted using typical parameters for designed working
  conditions. Then the former conclusions of driver’s emergency measures were obtained with the feasibility of
  test methods being verified, which provides references for the combination research of driving simulation and
  accident reconstruction.

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  Safe distance model and obstacle detection algorithms for a collision warning and collision avoidance system

  PEI Xiaofei, LIU Zhaodu, MA Guocheng, YE Yang

  2012, 3(1):  26-33.  doi:10.3969/j.issn.1674-8484.2012.01.004

  Abstract ( 2980 )   PDF (1907KB) ( 4418 )  

  Safe-driving was assisted with key parameters calibrated according to the driver’s characteristics
  using a developed system of vehicle collision warning and collision avoidance (CW/CA). The system defines the
  inverse of time-to-collision (TTC-1) as the evaluation index with the grading warning and braking safe distance
  model adopted based on hazardous level ε . A millimeter waveradar obstacle detection method was designed
  with adaptive cruise control (ACC). The system configuration and control logic were designed based on a Jetta
  car with the collision avoidance test and the manual / automatic interaction test implemented on dry roads. The
  real car experiments show that the CW/CA system in accordance with desired TTC-1 index improves vehicle
  active safety, and embodies the driver’s priority and cooperation.

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  Electrical safety of electrical vehicles in crash tests

  WANG Kai, LI Xiangrong, BAI Peng

  2012, 3(1):  34-37.  doi:10.3969/j.issn.1674-8484.2012.01.005

  Abstract ( 2243 )   PDF (1641KB) ( 2771 )  

  The electrical safety is more important in electrical vehicle crash compared with that of normal
  vehicles, because an electrical vehicle has high voltage in the power cycle. This paper analyzes electrical
  vehicle crash standards and regulations and investigates the crash test process. The difference between an
  electrical vehicle and a normal car was analyzed using the dummy head and thorax injury data and car body
  acceleration data, whose sources are the frontal and side impact test data by a laboratory at China Automotive
  Technology and Research Center, CATARC. Some suggestions were proposed in the establishment of China’s
  electrical vehicle crash standards and regulations. Electrical safety matters needing attention in the crash test
  were also suggested which is valuable for the establishment of the regulation and passive safety design.

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  Crashworthinessanalysis of spot-welded, adhesively bonded and bonded-welded front longitudinal beams

  2012, 3(1):  38-43.  doi:10.3969/j.issn.1674-8484.2012.01.006

  Abstract ( 2212 )   PDF (2003KB) ( 2618 )  

  Adhesively bonded technology process applied in a car body is useful to make the car body lighter.
  This paper contrasts and analyzes the crashworthiness of the front longitudinal beam of a real car under crash
  loading for three connection models of spot-welded, adhesively bonded and bonded-welded styles using a finite
  element model to meet the crashworthiness normal requirements and evaluating indicators for front longitudinal
  beams. The deformations were calculated under different crash velocities. The results show that the longitudinal
  direction equivalent stiffness of adhesive connection is higher than that of spot weld in low-speed (3.3 m/s)
  collision and lower in high-speed (13.2 m/s) collision. Connection modes have very little influence on the
  performance of the front longitudinal beams when connection loses efficacy in small scope.

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  Automotive Energy Efficiency & Environment Protection

  Impact factor analysis of the consumer acceptance of electric vehicle battery swapping service

  WANG Hewu, SONG Huayang, OUYANG Minggao*

  2012, 3(1):  44-50.  doi:10.3969/j.issn.1674-8484.2012.01.007

  Abstract ( 2412 )   PDF (1715KB) ( 1736 )  

  Battery swapping service (BSS) is one pathway to promote the commercialization of electric
  vehicles. To understand the acceptable of the electric vehicle’s Battery Swapping Service by consumers and
  impact factors, one survey with more than one thousand questionnaires were carried out in four cities (Beijing,
  Shanghai, Shenzhen and Chongqing) based on the “naked car sales – battery lease – battery swap” quickchange
  battery” business model, and the statistical analysis software SPSS was used. The results show that the
  consumer acceptance percent of BSS is more than 80% within the interviewers. The results also show that the
  advantages of longer battery life and saving recharge time, more environmental friendly and more convenient,
  have positive influence on the acceptance with the impact increasing in the mention above order

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  Detailed mechanism of NO reduction by CO over rhodium
  during rich period of diesel LNT

  SU Qingyun, WANG Sheng, LI Yanbin, SHUAI Shijin, WANG Jianxin

  2012, 3(1):  51-57.  doi:10.3969/j.issn.1674-8484.2012.01.008

  Abstract ( 1515 )   PDF (2145KB) ( 2149 )  

  The process of diesel exhaust NO reduction using CO as the reductant during the rich period of lean
  NOx trap (LNT) was investigated considering an important byproduct N2O. Detailed mechanisms for CO-NO
  and CO-N2O reactions over rhodium catalyst were proposed to numerically simulate experimental results, with
  different feed gas ratios for the CO-N2O reaction. Good agreement was obtained for both of the two reactions.
  The results show that N2O, as an important intermediate during NO reduction, undergoes further reactions with
  CO under certain conditions. Most of the N2 is produced through the N2O route during NO reduction at 475-
  620 K. The influence of the feed gas CO concentration on the isolated CO-N2O reaction was probed, and the
  rate-limiting step was determined to be the decomposition of N2O according to the analysis of the elementary
  reaction rate.

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  Thermodynamics Modeling and Simulating of Lithium-Ion Battery Pack under Electric Vehicle Driving Cycle

  LUO Yutao, TAN Di, HE Xiaochan

  2012, 3(1):  51-57.  doi:10.3969/j.issn.1674-8484.2012.01.009

  Abstract ( 2446 )   PDF (1768KB) ( 3218 )  

  Battery operation conditions for electric vehicles are varying with the vehicle load and driving
  cycle. 3-D thermal field of the lithium-ion battery pack on electric vehicle was modeled using a finite element
  analysis (FEA), based on the battery architecture and thermodynamics theory to analyze the thermal dynamic
  performance under driving cycles. The thermal efficiency evaluating method is brought forward. The real time
  thermal field distribution and the thermal efficiency of one real lithium-ion battery pack were analyzed with
  Beijing city driving cycle taken as the load constrain example. Simulation results show that the load constrains
  affect the thermodynamics. The results can be used in the future cooling system design process.

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  Nonlinear Constrained Component Optimization for the Powertrain Configuration of a Plug-in Hybrid Electric Vehicle Powertrain

  Emrah T. YILDIZ , Quazi FAROOQI , Sohel ANWAR*, Yaobin CHEN , Afshin IZADIAN

  2012, 3(1):  64-70.  doi:10.3969/j.issn.1674-8484.2012.01.010

  Abstract ( 2679 )   PDF (1743KB) ( 1584 )  

  Particle Swarm Optimization (PSO) approach was used to optimize the size of the vehicle
  powertrain components (e.g. engine power, electric motor power, battery energy capacity) while meeting the
  critical performance requirements, improving fuel efficiency, and obtaining cost effectiveness for a plug-in hybrid
  electric vehicle (PHEV). Compared with conventional optimization methods, PSO isan efficient and precise
  optimization method for nonlinear constrained optimization problems.The PHEV powertrain configuration with
  the optimized components was used to form a new vehicle model using Powertrain System Analysis Toolkit
  (PSAT). Simulation results show that the vehicle with optimized components using PSO have equivalent
  operational performance and 30% improvement on fuel consumption.

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  Attenuation test and duplication of power battery’s cycle life

  2012, 3(1):  71-76.  doi:10.3969/j.issn.1674-8484.2012.01.011

  Abstract ( 2410 )   PDF (1776KB) ( 3198 )  

  Cycle life of power battery has a direct effect on the use of electric vehicles. This paper investigates
  the life prediction methods by inducing cycle life degradation model of power battery based on nickel-metal
  hydride batteries and manganese-based lithium ion batteries. Batteries were tested with reference of the
  test method of FreedomCAR, the U.S. Department of Energy's fuel cell vehicles development programs, and
  combined with the conventional power battery operating condition of China. Life decay way was studied with
  the combination of normal cycle and bus cycle, with the fitting formula of battery cycle life attenuation being
  determined. The results show that the Ni-MH battery and Li-ion battery capacities fade with cycle number
  followed an exponential decay distribution and the 1/2 power change path respectively. The cycle life model
  and reliability evaluation method are helpful for battery life prediction and establishing an accelerated cycle life
  prediction model.

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  Soot particles generation characteristics and size distribution in a diesel engine using an improved soot detail model

  JU Hongling , CHENG Xiaobei , WANG Fangyang , WANG Zhi

  2012, 3(1):  77-83.  doi:10.3969/j.issn.1674-8484.2012.01.012

  Abstract ( 2205 )   PDF (2433KB) ( 2362 )  

  Soot emission mass distributions and particle size distributions in diesel engines were simulated using
  an improved soot model. The soot emission mass was measured in a single cylinder diesel engine using a low
  pressure impactor (LPI). The model was developed based on an existing detailed soot model with the following
  three improvements, using n-tetradecane as fuel instead of n-heptane, coupling “shell” auto-ignition model with
  other models in KIVA-3V, and in the multi-steps soot model, considering PAHs (polycyclic aromatic hydrocarbons)
  direct deposition at the soot particle surface. The results show that PAHs deposition makes great contributions to
  increase soot particle mass with soot particle size determined by the development of PAHs in different stages and
  that the soot particle formation change trend by simulation is consistent with that by measurement. Therefore, the
  improved soot model can preferably predict the change trend of soot particles generation characteristics.

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