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• 2013, Vol. 4 No. 3
  Published on:25 September 2013 Previous issue    Next issue
  Progress & Prospects

  Diesel Emission Technology Development in Japan

  Akira WATANABE, Toshitaka MINAMI

  2013, 4(3):  185-201.  doi:10.3969/j.issn.1674-8484.2013.03.001

  Abstract ( 1705 )   PDF (16158KB) ( 1502 )  

  The pioneering research works on the high pressure fuel injection and the pilot injection
  technologies are introduced to overview the pathway of the engine emission technology development in Japan.
  In the first decade of the 21 century, the diesel engine technology realized an ideal combustion as an internal
  combustion engine, like exhaust gas regeneration (EGR) lean burn combustion. Another breakthrough was
  made in new after treatment systems. The real world problems of the after treatment are discussed in pursuance
  of further improvement. Since the diesel passenger car market is small in Japan, the diesel engine technology
  development has mostly been driven by commercial vehicle engine technologies. However, driving conditions of
  commercial vehicles (trucks and buses) and the sulphur content in fuel are different in different countries. These
  factors significantly affect diesel emission control strategies and design.

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  Research and development of automobile electromagnetic brake technology for commercial vehicles

  HE Ren, HU Donghai, ZHANG Duanjun

  2013, 4(3):  202-214.  doi:10.3969/j.issn.1674-8484.2013.03.002

  Abstract ( 2373 )   PDF (4938KB) ( 4895 )  

  Electromagnetic brakes (EBs) are widely applied in commercial vehicles for their characteristics of
  contactless, fast response, and simple controlling. The principle and research situation of EBs were given to
  expand their application scopes and functions. The application status, the structure, the working principle and
  the control method of EBs were discussed to three main EBs including the eddy current retarder, the rotary eddy
  current retarder, and the self-excited retarder for commercial vehicle. The results show that the key technologies
  are the external and inner characteristics of the electromagnetic brakes, the matching designs and the design
  of control strategy and the controller of united braking system of both electromagnetic and friction. Technology
  focus for electromagnetic braking will be the integrated system of electromagnetic brakes and frictional brakes,
  and function extension of electromagnetic brake system.

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  Automotive Safety

  FE simulation of the occupant crash protection performance of the negative Poisson's ratio seat belt webbing

  QI Chang, AN Wenzi, YANG Shu

  2013, 4(3):  215-222.  doi:10.3969/j.issn.1674-8484.2013.03.003

  Abstract ( 1286 )   PDF (2743KB) ( 1882 )  

  A concept of seat belt webbing with negative Poisson's ratio (NPR) characteristic was proposed
  for mitigating the harm to occupants by the seat belt in car-crash accidents. A finite element (FE) model with a
  simplified human chest model was established and used for webbing performance simulation. The occupant
  protection performances of NPR webbing were compared with that of the traditional webbing. The effects of
  Poisson’s ratio and friction coefficient on the NPR webbing’s performance were investigated. The effectiveness
  of the NPR webbing was verified by MADYMO dummy crash simulation. The results indicate that compared with
  the traditional seat belt webbing, the NPR webbing can effectively reduce the occupant chest deflection; the
  smaller the Poisson’s ratio, the better the protection performance; friction between the occupant chest and the
  NPR webbing is not conducive to the effectiveness of the NPR webbing.

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  Standard Object of Pedestrians for Automotive Radar Application Systems and its Radar Cross Section Measurement

  BAI Jie, ZHOU Gen

  2013, 4(3):  223-227.  doi:10.3969/j.issn.1674-8484.2013.03.004

  Abstract ( 1414 )   PDF (1704KB) ( 2775 )  

  Automotive radar is a kind of key sensor for the range detection of objects in Advanced Driver
  Assistance Systems (ADAS) such as the pre-crash system and the backing aid system. Radar cross section
  (RCS) was measured as an important reference data to evaluate and compare the radar’s performances. After
  analyzed methods of measuring and calibrating RCS, a standard object was developed to represent pedestrian
  in vehicle radar performance tests. The RCS was measured for small targets (such as a pipe) with length of
  1 m and RCS below 0 dB to analyze the influence of different characteristics of pipe such as the material,
  diameter, and inclination angle on the RCS. Radio wave reflection and absorption properties of test objects
  were evaluated as well. The results show that by setting up a standard object of pedestrians, it is easier to test
  performance of any ADAS application system, therefore, improving radar’s ability to detect pedestrians.

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  Prediction on vehicle acceleration and its application in frontal angular impact sled tests

  2013, 4(3):  228-231.  doi:10.3969/j.issn.1674-8484.2013.03.005

  Abstract ( 1340 )   PDF (1304KB) ( 1924 )  

  Vehicle body longitudinal axis at sled tests, which have been widely used to simulate the full-width
  frontal impact at present, isusually parallel to sled movement direction. Therefore, occupants' motion attitude
  cannot be simulated due to vehicle rotary motionin angular impact test. This paper simplifies the vehicle angular
  impact,analyzes kinetic model. A new method was used to accurately determine the deflection angle of the
  vehicle body and the input pulse of the sled in angular impact sled test to calculate the acceleration vectors in
  vehicle body by combining with the vehicle acceleration signals of the real vehicle crash test. By comparing the
  head injuries and chest injuries, the results show that improved sled test method has better simulation accuracy
  than the existing sled test method.

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  Optimization of excessive pedal intrusion in 40 % offset crash on a specific vehicle

  GUAN Lijun1, XIAO Haitao, QI Hongjuan, LIU Weiguo, WANG Chun, ZHOU Dayong, ZHAO Fuquan

  2013, 4(3):  232-237.  doi:10.3969/j.issn.1674-8484.2013.03.006

  Abstract ( 1313 )   PDF (2761KB) ( 1432 )  

  The 64-km/h 40% offset deformable barrier (ODB) frontal crash is an important item in the China
  New Car Assessment Program (C-NCAP) and inthe Euro-NCAP test. This paper calculates the deformation at
  pedal fixing area using a vehicle crash simulation model and analyzes deformation mode of side rail in engine
  room to solve the excessive pedal intrusion into a vehicle in 40% offset crash, and gives an optimized solution
  to vehicle body structure. The simulation validation results show that acceleration pedal reward is reduced by
  48.5% with the upward being reduced by 29.1%, therefore, center tunnel area strength is enhanced, and pedal
  fixing area structural deformation is lessened incrashes,which improves the energy-absorbing effect of left side
  rail in engine room, perfects deformation mode, and reduces pedal intrusion. Therefore, the optimized solution
  solves excessive pedal intrusion of this vehicle, therefore improving vehicle safety.

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  Influencing factors of the rear-row female’s chest injury in the frontal impacting tests

  2013, 4(3):  238-243.  doi:10.3969/j.issn.1674-8484.2013.03.007

  Abstract ( 1197 )   PDF (2091KB) ( 1618 )  

  The rear-row female chest is the emphases lost score position in the frontal impacting test in the
  new China New Car Assessment Program (C-NCAP). The research of female chest injury influencing factors is
  passive safety emphases. The authors investigated the sternum rigidity for 5% male dummy, the seat belt action
  effect, the seat belt action time, the dummy relative move using a contrast method between a rear-row female
  dummy and a front-row 50% male dummy in twelve frontal impacting tests at 50 km/h. The results show that
  female dummy sternum rigidity islower than male, about half of it, when using a general seat belt, and that the
  effective action start time is about 30 mslater than male, and a sudden-hold impacting occurred in the impact
  end stage; and that the chest injury severity of the rear-row female dummy in impaction with using seat belt by a
  5% female dummy is designed for 50% male dummy. Therefore, a higher rigidity of vehicle front part can make
  a better protection for female dummy chest.

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  Dynamic Response and Injury Risk of Pedestrians in Mini Car Collision

  HAN Yong , MIZUNO Koji , MATSUI Yasuhiro

  2013, 4(3):  244-249.  doi:10.3969/j.issn.1674-8484.2013.03.008

  Abstract ( 1291 )   PDF (1707KB) ( 1693 )  

  Dynamic response was investigated for pedestrian struck injury risk ina minicar collision. Vehicle
  collisions were simulated using a total human finite element model (THUMS) at speed of 40 km/h with a dummy
  of 165 cm and 60 kg. The injury parameters analyzed includes low extremity bending moment, knee joint
  bending angle, chest impact velocity, head impact velocity, and head injury criterion (HIC). The results show that
  all of the high bending moment, the lower leg bending moment, and the knee bending angle are lower than that
  of the injury acceptance levels; both the upper thorax and scapula are at fracture risk due to the impact by the
  cowl area having a relative high stiffness structure; and that the head injury risk is low with head impact velocity
  of 10.4 m/s, because the impact location is windshield with lower stiffness. Therefore, the injury risk is low when
  pedestrian is hit at front conformation for a similar mini car.

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  Comparison on three methods for simulating safety airbag deployment

  CHE Kaikai, WANG Meisong

  2013, 4(3):  250-256.  doi:10.3969/j.issn.1674-8484.2013.03.009

  Abstract ( 1539 )   PDF (6916KB) ( 3357 )  

  Numerical simulation technology is an important tool to reduce cost and time for safety airbag
  development. Three prevalent principal methods, i.e. the Control Volume Method (CV), the Arbitrary Lagrangian
  Eulerian Method (ALE), and the Corpuscular Method (CPM), were compared for the application and the
  characteristics of airbag. The deployment process, the temperatures, and the pressures were simulated using
  mathematic theories and finite element model for a developing vehicle with a folded driver side airbag. The
  simulation results of these methods show that the CV method is more suitable for airbag simulation under in
  position (IP) condition, while the ALE method and the CPM method are perfect for analyzing the flow field and
  its effects on passengers of airbag deployment under out of position (OOP) condition when taking into account
  flow effect at the initial stages of airbag deployment. These results will provide references for the selection
  simulation method and actual design for airbag deployment.

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  Simulations and tests according to the new regulations of school buspassive safety

  CHE Kaikai, WANG Meisong

  2013, 4(3):  257-265.  doi:10.3969/j.issn.1674-8484.2013.03.010

  Abstract ( 1067 )   PDF (7822KB) ( 1384 )  

  The production of school buses and its safety problems have been wide spread concerned by
  public. A new style long-nose school bus was produced by the authors' company according to the new passive
  safety regulations for school buses promulgated in China in 2012. Simulations and tests were done for the roof
  strength, rollover under the guide of school bus regulations items to evaluate safety performances, such as the
  collision forces and the deformations of vehicle structure, and the accelerations and the loads in some parts
  of dummies under boundary condition offrontal impact, side impact and rear crash.Based on the simulation
  analysis, the design scheme was improved for some crucial load bearing structures, such as seat system,
  and energy-absorbing crush zone.The results show that the consistent of simulation with the experimental
  results evidences the credibility of simulation analysis; and that the improved school-bus-structure has higher
  crashworthiness than before. Therefore, itminimizes the damage to passengers in road accidents, and then,
  satisfies passive safety regulation demands.

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  Optimization design of front-end structure for flexible legform of pedestrian protection in crash

  LV Chengwei , YANG Haiyan , LV Xiaojiang , ZHOU Dayong , LIU Weiguo

  2013, 4(3):  266-272.  doi:10.3969/j.issn.1674-8484.2013.03.011

  Abstract ( 1246 )   PDF (2966KB) ( 1895 )  

  The front-end structure of a developing car was optimized to achieve the target of Flexible
  Pedestrian Legform (Flex PLI) with a full mark of 6 score in a crash under the Euro-New Car Assessment
  Program (Euro-NCAP). The energy-absorbing devices for front cross members and lower braced structures
  were optimized using the Computer-Aided Engineering (CAE) technique. Soften-hole was widened to 35 mm,
  and conduct-surface was added against press-break for energy-absorbing devices. Two connective structures
  were removed from lower braced structures. The thickness oflower braced structures was reduced to 0.8 mm.
  The result shows that the absorbers perform better in deformation, and absorb 22 kJ more. The tibia-mid upper
  bending moment is reduced by 106 Nm. With the work of lower support, the middle part of legform moves 25
  mm more in X direction while the bottom of legform moves 15 mm less in X direction, and reduces the medial
  collateral ligament elongation by 17.8 mm. Therefore, a full mark 6 is obtained.

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  Automotive Energy Efficiency & Environment Protection

  Evaluations and purchase intentions by EV test drivers

  FU Gangzhan, WU Xiaoyuan, ZHOU Minjie, SHI Huan, WANG Jian

  2013, 4(3):  273-278.  doi:10.3969/j.issn.1674-8484.2013.03.012

  Abstract ( 1086 )   PDF (1192KB) ( 1778 )  

  Investigation on test drivers is an important way for the potential consumers’ evaluations and
  purchase intentions of a new car coming into the market. This paper analyzes test-drivers’ perceptual
  evaluations and purchase intentions using a questionnaire survey of 668 test-drivers collected in Shanghai
  International Automobile City Test Drive Center as basic data, with using SPSS statistical analysis software to do
  frequency analysis, cross analysis, correlation analysis and Logistic regression analysis. The analysis included
  the individual characteristics and the preferences of test-drivers and their evaluations on electric vehicles (EVs)
  performances. The results show that EV potential buyers are male customers, who already have cars, travel
  more than 10 km to work with requiring EV speed of 60-80 km/h, and they prefer EV charging in public parking
  lot, and they worry more about EV charging infrastructure and after-sale service than the higher price of EV.

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  Torque coordinating optimal control for dry dual clutch transmission in shifting process

  ZHAO Zhiguo, WANG Qi, CHEN Haijun, DIAO Weizhen

  2013, 4(3):  279-278.  doi:10.3969/j.issn.1674-8484.2013.03.013

  Abstract ( 1208 )   PDF (1836KB) ( 2360 )  

  A torque coordinating optimalcontrol strategy was developed using different driving intentions in
  different shifting process phases for a six-speed Dry Dual-Clutch-Transmission (DDCT) of a self-developed car.
  A simulation model was set up on the Matlab/Simulink software platform and then used to simulate the control
  strategy for DDCT shifting process. The sub-divided phases included the quadratic optimal control adopted in
  torque phase; the ignition parameters and fuel supply controlin inertia phase; the control factor mapping method,
  which reflects driving intension, both in micro-slipping phase and in demanded torque switching phase. The
  results show that shift jerks are within -2 m/s3 while the total frictional energy losses are within 2 kJ in shift
  process. Therefore, this control strategy reflects driving intentions and meets the demand of shift quality.

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