Current Issue

• 2016, Vol. 07 No. 02
  Published on:25 June 2016 Previous issue    Next issue

  Present and future of studies for diesel engines using biodiesel fuel

  LOU Diming, TAN Piqiang

  2016, 07(02):  123-134.  doi:10.3969/j.issn.1674-8484.2016.02.001

  Abstract ( 304 )   PDF (2678KB) ( 1718 )  

  Biodiesel, which commonly refers to fat acid methyl esters made from vegetable oils or animal fats, is a kind of ideal alternative fuel for diesel engines. Compared to pure petroleum diesel fuel, biodiesel has higher cetane number, including oxygen, higher viscosity, lower heating value, almost no aromatic hydrocarbon and sulfur. This leads to different fuel injection and spray properties, combustion characteristic, power and fuel consumption, exhaust emissions from petroleum diesel fuel. Compared to pure petroleum diesel fuel, biodiesel has earlier fuel injection timing, longer spray penetration and smaller spray angle, and shorter ignition delay. Diesel engines have lower mass of CO, HC, smoke, and particulate matter (PM) emissions when using biodiesel, and the reduction percentages are proportional to blend ratios of biodiesel fuel. But NOx , aldehyde and ketones emission have slightly increase, as well as number concentration of nucleation mode particles. High pressure common rail fuel injection system and exhaust gas after-treatment technology for biodiesel are important directions in future.

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  Progress & Prospects

  Thermoelectric Materials and Thermal Spray Process for Vehicle Waste Heat Recovery

  ZUO Lei, FU Gaosheng, YU Liangyao

  2016, 07(02):  135-150.  doi:10.3969/j.issn.1674-8484.2016.02.002

  Abstract ( 312 )   PDF (4593KB) ( 1394 )  

  With the global concerns on energy and environmental issues, various approaches of energy harvesting have been explored. As a solid state energy generator, Thermoelectric Generators (TEGs) can convert the temperature gradients to electrical voltage, thus recovery the energy from vehicle exhaust heat and increase overall efficiency. Recently a new industry-scalable thermal spray process has been extended for the integrated manufacturing of thermoelectric generators on the exhaust pipes directly. This paper is to provide a timely review of the state-of-the-art on thermoelectric materials and thermal spray fabrication process for the
  applications of vehicle exhaust heat recovery. They can also be used for energy harvesting in the power plants, manufacturing processing, and many others.

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  Automotive Safety

  Review on the research of motion control for intelligent vehicles

  GUO Jinghua, LI Keqiang, LUO Yugong

  2016, 07(02):  151-159.  doi:10.3969/j.issn.1674-8484.2016.02.003

  Abstract ( 499 )   PDF (2107KB) ( 3166 )  

  This paper discussed the research status of motion control theories and the methods of intelligent vehicles with analyzing the lateral and longitudinal motion control technique of intelligent vehicles to promote the comprehensive driving performance of intelligent vehicles. The present study focused on the independent design of longitudinal and lateral control strategy of intelligent vehicles by the decoupling method, without considering the random uncertainty and time delay of vehicles, and with a single performance goal and utilized not effectively communication technology. Hence, the important research directions of dynamical control for intelligent vehicles in the future will be coordinated multi-objective and multi-system control of intelligent vehicle through the wireless communication and multi-sensor information fusion technology to make intelligent vehicles with optimal performances having a traffic environment on safety, comfort, fuel efficiency and environmental protection.

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  Quantitative electroencephalography analysis for index of drowsy driving

  CHEN Chaoyang, WANG Wenjun, ZHANG Chaofei, CHENG Bo, ZENG Chao,

  2016, 07(02):  160-166.  doi:10.3969/j.issn.1674-8484.2016.02.004

  Abstract ( 281 )   PDF (2900KB) ( 2253 )  

  The characteristics of electroencephalograph (EEG) parameters among drowsy drivers were investigated to define physiologic index of driving fatigue. Quantitative EEG (qEEG) analysis techniques were used among 22 subjects using a driving simulator to extract δ band power and 90% spectral edge frequency (SEF90) and to analyze the parameters' changes during drowsy driving and the differences from various recording locations by using binary logistic regression, discriminant classification, and receiver operating characteristic (ROC) curve. The results show that 60 minutes’ mono- environment driving lets to driving drowsiness with increase of relative δ band power and decrease of SEF90. The EEG quantitative changes recorded at the temporal regions are more than that recorded at the frontal regions. Therefore, the increase of normalized δ band power can be used as an indicator to discriminate the alert from drowsy state during driving. Decrease of SEM90 can be another indicator to determine the drowsiness during driving.

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  Leading vehicle detection at night based on millimeter-wave radar and machine vision

  JIN Lisheng, CHENG Lei, CHENG Bo

  2016, 07(02):  167-174.  doi:10.3969/j.issn.1674-8484.2016.02.005

  Abstract ( 298 )   PDF (2614KB) ( 2149 )  

  A leading-vehicle night-detection method was proposed based on millimeter-wave radar-vision, using the fusion of data from multi-sensors to investigate the intelligent warning system for avoidance vehicles collision at night with preceding vehicles. A world coordinate of the preceding vehicles was built for millimeter
  wave radar target to form the region of interesting image after relationship transformation from the world coordinate to image pixels coordinate. Image processing method reduced interference from the outside environment. A general value of reliability was achieved to test vehicles in interest depending on Dempster-
  Shafer Evidence Theory (D-S) which fused feature information. Several sections of video for vehicles driving on road were collected during experiment. The statistical data of frames of taillight identified were achieved and compared by subjective judgment. The results show that the method effectively eliminates the influence of illumination condition at night, accurately detect leading vehicles and determine their location.

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  Differences of anthropometric dimensions between Chinese and American and the effects on drivers’ injury risks in vehicle frontal crash

  ZHANG Jinhuan, YANG Jie, JIN Xin, SHEN Ming, LUO Xiao, MA Chunsheng

  2016, 07(02):  175-181.  doi:10.3969/j.issn.1674-8484.2016.02.006

  Abstract ( 273 )   PDF (2127KB) ( 1177 )  

  American drivers, were created based on the anthropometric dimensions, and frontal crash simulations were conducted. The results showed that for a specific vehicle model, Chinese 5th percentile female and 50th percentile male drivers have higher injury risks compared to the corresponding percentile American
  drivers at 30-50 km/h. However, Chinese 95th percentile male drivers suffer lower injury risk relative to American 95th percentile male drivers at 30-60 km/h. It is advisable to take the differences of anthropometric dimensions between Chinese and American into consideration in enacting the vehicle safety regulations and developing new vehicle models in China, so that the vehicles in China can more effectively protect the Chinese drivers.

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  Conceptual design for electric vehicle body structure based on topology optimization

  WANG Wenwei, JIANG Weiyuan, GAO Fengling, CHENG Yuting

  2016, 07(02):  182-187.  doi:10.3969/j.issn.1674-8484.2016.02.007

  Abstract ( 288 )   PDF (2172KB) ( 1122 )  

  A new 3-D topology optimization design space of chassis was constructed in the conceptual design stage of an electric vehicle white body to develop the body structure which satisfies the characteristics and requirements of electric vehicle. Single objective topology optimization designs of bending, torsion, and crash
  conditions were conducted respectively using topology optimization method based on Solid Isotropic Material with Penalization (SIMP), considering the differences of body structure between electric and combustion-engine automobile. The optimal load transmitting path and the connections of supports for chassis were obtained. The results show that the optimization can meet the design requirements and provide proposal for the detailed design in the next stage or other electric vehicle models.

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  Finite element method on the impact of axial preload on the stiffness of deep-groove ball-bearing

  YE Haiyan, ZHOU Chi, FAN Zijie

  2016, 07(02):  188-195.  doi:10.3969/j.issn.1674-8484.2016.02.008

  Abstract ( 310 )   PDF (2818KB) ( 1275 )  

  Finite element analysis (FEA) is very difficult to converge when deep-groove ball-bearings are under axial load. This paper proposed a finite element method (FEM) to solve the converge problem and to analyze the impact of axial preload on the stiffness of deep-groove ball-bearing by adjusting the position of each part based
  on theoretical calculation and by reasonably using enforced displacement. The proposed method was presented on deep groove ball bearing under axial force and combined forces. The FEA solution of contact deformation agrees well with the theoretical result within 5%, which proves the correctness of the FEM. The results show that the inverse of the slope of axial deformation-preload curve increases with preloads, so axial stiffness is improved. Moreover, with constant radial loads, preloads have little impact on the radial deformation when they increase within 200~400 N, which provides a reference for the design of preloads.

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  Conceptual Design of B-Pillar Load Path for Reducing Vehicle Side Impact Intrusion

  ZHOU Qing, PRAWIRA Darwin

  2016, 07(02):  196-201.  doi:10.3969/j.issn.1674-8484.2016.02.009

  Abstract ( 422 )   PDF (2497KB) ( 1044 )  

  In vehicle side impact collisions, side structure intrusion must be controlled to reduce risks of injuries and fatalities to occupants. This paper proposes adding a structural mechanism between B-pillar and seat frame as an additional load path to distribute partial side impact load to seat frame and vehicle structure for reducing side structure intrusion. Design requirements and a conceptual design are described. The added structure can also serve as an armrest and is retractable in order not to affect ingress and egress of occupant. The device can be automatically positioned by the door opening and closing. Requirements on ergonomics and anthropometric have been considered in the design to ensure that the side impact load transfer function and the armrest function can work properly in the main ranges of human anthropometry dimensions and seat positions.

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  Submarining mechanism for H Ⅲ 5th female dummy and antisubmarining plans

  ZHANG Xiao, LIU Shuang, YANG Li

  2016, 07(02):  202-209.  doi:10.3969/j.issn.1674-8484.2016.02.010

  Abstract ( 454 )   PDF (2268KB) ( 1201 )  

  The submarining mechanism for a H Ⅲ 5th rear female dummy was analyzed and some antisubmarining plans were put forward to meet the requirements of rear female occupant submarining in C-NCAP (China-New Car Assessment Program) implemented on July 1, 2015. The dummy movement was simplified and the equal condition in which relative slippage did not occur between lap belt and dummy abdomen during crash was obtained. Some anti-submarining plans were brought out considering one real-world vehicle situation, aiming at dummy abdomen obliquity and the angle between lap belt acting force direction and horizontal level respectively. 10 plans were validated through the MADYMO software. 4 plans were applied to the real-world vehicle validation tests. The results show that the iliac unloading rate is less than 1 kN/ms. Therefore, the antisubmarining plans are effective because no submarining happened according to the C-NCAP (2015).

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  Key technologies of the powertrain of a typical fuel cell sedan

  FANG Chuan, XU Liangfei, LI Jianqiu, OUYANG Minggao

  2016, 07(02):  210-217.  doi:10.3969/j.issn.1674-8484.2016.02.011

  Abstract ( 299 )   PDF (2552KB) ( 1410 )  

  The innovative technologies on the powertrain of a kind of foreign-country mass-produced fuelcell sedan were analyzed to further promote research and development of China’s fuel cell vehicles. These technologies promoted the maximum power, environmental adaptability, reliability, durability, hydrogentank
  mass effectiveness, as well as reduced cost, so that popularized fuel cell application onto vehicles. The powertrain topology, the fuel cell stack assembly, high pressure hydrogen storage system on this kind of sedan are of significance to global fuel cell researchers, so do the internal self-humidification of the fuel cell system and bipolar plate design.

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  Simulation and experiment on direct torque control based on space vector pulse width modulation of PMSM

  ZHOU Xiaomin, ZHAO Like, GAO Dawei

  2016, 07(02):  218-223.  doi:10.3969/j.issn.1674-8484.2016.02.012

  Abstract ( 270 )   PDF (4277KB) ( 1348 )  

  A direct torque control (DTC) method based on Space Vector Pulse Width Modulation (SVPWM) algorithm was investigated by simulation based on Matlab/Simulink and experiment based on DSP28335 motor control system to solve the problems of the torque and flux ripples and current distortion of traditional DTC for
  Permanent Magnet Synchronous Motor (PMSM). The working conditions were of loading torque 20 Nm after starting to 1 500 r/min and stepping torque to 60 Nm and 40 Nm while the speed was stable at 1 500 r/min. The motor runs stably and the noise reduced obviously during the whole experiment process. The results show that the DTC based on SVPWM improves the system control performance by reducing the torque ripples 5.6% and 14% respectively and achieves the circle flux waveform effectively comparing with traditional direct torque control. Therefore, using the proposed method can solve the problem that the traditional DTC only can select one basic voltage vector to control in each control cycle.

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  Driving pattern recognition and charging management-based intelligent control strategy for extended-range electric vehicle

  2016, 07(02):  224-229.  doi:10.3969/j.issn.1674-8484.2016.02.013

  Abstract ( 230 )   PDF (2334KB) ( 848 )  

  The driving cycle of extended-range electric vehicle (E-REV) was analyzed with constructing an intelligent control strategy based on driving pattern recognition and battery charging management to improve the storage ability of clean electricity energy for hybrid electric vehicle (HEV). The strategy was used to control a extender working in different condition according to current driving cycle categories. The strategy would determine the extender-off time according to the distance between charging station and the driver's current position when the driver decided to recharge battery from outlet and reduce state of charge (SOC) to an ideal value as the vehicle arrive at the charging station. The results show that the strategy can reduce SOC to 30%~35% compared to that of constant power control strategy when a E-REV arrives at the charging station.

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  Electrical inertia simulation for electric vehicle based on energy equivalent and acceleration equivalent

  ZHA Hongshan, LIU Kang

  2016, 07(02):  230-235.  doi:10.3969/j.issn.1674-8484.2016.02.014

  Abstract ( 288 )   PDF (2386KB) ( 1180 )  

  Two electrical-inertia-simulation methods were proposed based on acceleration equivalent and based on energy equivalent respectively to test and evaluate the energy consumption in the early stages of development of the electric vehicles. According to the principle of acceleration equivalent simulation, either time correction or torque correction was adapted to compensate the energy difference between bench simulation and vehicle consumption. Two methods for electrical inertia imulation, the energy equivalent and the equivalent acceleration, were compared to their advantages and applied fields by theoretical analysis and simulation
  testing. The results show that the acceleration equivalent method is suitable for the dynamic performance test, and the proposed energy equivalent method is more suitable for the test of energy consumption. Therefore, the combination of the two inertia simulation methods can be used to simulate the dynamic performance and energy consumption characteristics of the electric vehicles.

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  XPS analysis of soot oxidation characteristics with Si-Al catalyst effects

  HU Jing, HU Zhun, ZHANG Jun, SHUAI Shijin

  2016, 07(02):  236-240.  doi:10.3969/j.issn.1674-8484.2016.02.015

  Abstract ( 213 )   PDF (1873KB) ( 946 )  

  X-ray photoelectron spectroscopy (XPS) analysis was used to investigate effects of catalyst on soot oxidation characteristics, existing form and differences of soot and partially oxidized soot were examined. Printex-U (PU) was used to surrogate engine soot, soot became more and more ordered crystalline structure with the temperature increasing with no catalyst added. Soot added catalyst appeared similar oxidation mechanism as well as the microstructure with finish oxidation at 650 ℃ . However, soot appeared lesser ordered crystalline structure under high oxidation temperature of 1000 ℃ . The results show that Si-Al catalyst changes the soot oxidation mechanism under oxygen atmosphere, catalyst with finish oxidation at 1 000 ℃ promotes oxidation of ordered crystalline structure which was difficult to be oxidized.

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