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Welcome to Journal of Automotive Safety and Energy,
汽车安全与节能学报

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  • 2019, Vol. 10 No. 1 Published on:31 March 2019 Previous issue    Next issue
    Progress & Prospects
    Research and development of autonomous emergency brake（AEB) technology
    HE Ren, FENG Haipeng
    2019, 10(1):  1-15.  doi:10.3969/j.issn.1674-8484.2019.01.001
    Abstract ( 903 )   PDF (1599KB) ( 5453 )  

    A research progresses on the working principle, development path, application status and regulation of the autonomous emergency braking (AEB) technology were introduced to promote the car’s autonomous emergency braking technology to be safer and more efficient. The key technologies related to the
    comprehensive performance of AEB system were summarized, including collision avoidance strategy, braking execution technology and front-end perception technology. The results show that AEB system can effectively avoid or mitigate collision, which can greatly improve the vehicle's active safety performance. However, AEB system can’t avoid any collision at higher vehicle speed and more complex traffic scenarios on account of low level braking execution technology and front-end perception technology. The technology focus for AEB will be comprehensive performance optimization of collision avoidance strategy in more complex traffic scenarios, the development of brake actuators based on shorter response time objectives, and the deep integration and the coordinated control of multiple active safety technologies under dangerous driving conditions.

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    Technology analysis of heavy-duty diesel vehicles to meet near zero emission regulations
    SHUAI Shijin, LIU Shiyu, MA Xiao, et al
    2019, 10(1):  16-31.  doi:10.3969/j.issn.1674-8484.2019.01.002
    Abstract ( 311 )   PDF (2294KB) ( 1671 )  

    Diesel engines need co-optimization for in-cylinder purification and high efficiency exhaust aftertreatment technologies to meet the increasingly stringent emission regulations in the future. This paper compared different current emission regulations in Europe, the USA and China for heavy-duty diesel vehicles.
    The analysis results show that for the diesel vehicles which meet the China VI, Euro VI, and US 2010 regulations, the influence of the harmful emissions on air can be neglected, so these regulations can be defined as near-zero emissions. To achieve the near-zero emission regulations, several in-cylinder clean combustion and aftertreatment technologies were described; based on these technologies, two technical routes of exhaust gas recirculation (EGR) and selective catalyst reduction (SCR)-only were summarized. To meet the ultra-low NOx emission regulation in USA California, two technical routes of passive NOx absorber (PNA) and close-coupled SCR were compared. The results show that the EGR route has good control effect on low temperature NOx emission; the SCR-only route has good fuel economy; the PNA route has low NOx emissions and simple system structure; while the close-coupled SCR technology has low cost and good durability.

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    Automotive Safety
    Development of a 3-D geometric database of Chinese children body shape in seated posture
    CAO Libo, TAO Wukang, TAN Lifan, et al
    2019, 10(1):  32-36.  doi:10.3969/j.issn.1674-8484.2019.01.003
    Abstract ( 172 )   PDF (1281KB) ( 503 )  

    A three-dimensional geometric database was established for Chinese child body shape in seated posture based on Microsoft's Kinect scanning device and other algorithms. The database used a sitting scanning experimental platform of the second generation of Microsoft's Kinect to collect various characteristics
    with different percentiles of sitting posture models from 89 children volunteers at the ages of 6~12. A human body model processing program written in C++ was used for the acquired models to perform some processes such as smoothing and de-noising. The obtained two-dimensional and three-dimensional data were integrated and processed by using software Microsoft Access 2016. The results scanned from children volunteers show that the length average error of the human body model is 6.6 mm with high precision and high credibility. Therefore, the three-dimensional geometric database can be used as a data foundation of research, design and development of Chinese products such as child seats.

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    Acceleration distribution characteristics of the driver and its application
    LIU Rui, ZHU Xichan
    2019, 10(1):  37-45.  doi:10.3969/j.issn.1674-8484.2019.01.004
    Abstract ( 264 )   PDF (1366KB) ( 862 )  

    The accelerating behavior characteristics of the driver were studied by using the naturalistic driving data (NDD) to improve the human-like driving ability of the intelligent vehicle. The database composed of approximately 58 million observation data was applied to discuss the convergence of the acceleration
    distribution of the driver. The multivariate kernel density function was used to achieve the acceleration distribution of the driver. The relative entropy (Kullback-Leibler divergence) was employed to describe the distinction among the datasets which were composed of different amount of data. The acceleration distribution
    of the driver was analyzed, and its parameters were achieved by using the convergent dataset. The application of the acceleration distribution characteristics of the driver in intelligent vehicle were discussed. The results show that the 2-dimensional distribution between the longitudinal acceleration and lateral acceleration follows the dual triangle distribution pattern. The longitudinal acceleration and lateral acceleration firstly increase and then decrease when the velocity increases. The acceleration distribution can be applied in the intelligent vehicle driving capability evaluation, intelligent vehicle safety test, co-driving control,   risk  assessment algorithm, etc.

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    Deviation warning system for guardrail cleaning tankers based on vision
    LIAO Jiacai, CAO Libo, XIA Jiahao
    2019, 10(1):  46-53.  doi:10.3969/j.issn.1674-8484.2019.01.005
    Abstract ( 173 )   PDF (1858KB) ( 380 )  

    A vision-based guardrail detection method was proposed and used on the cleaning vehicle deviation warning system to obtain the accurate distance information between the guardrail cleaning tanker and the guardrail, and to avoid the distracted driving and fatigue driving which was caused by the driver simultaneously
    observing the position of the guardrail and operating the tanker. The binocular stereo vision was used to obtain the exact distance value of the guardrail. By combining the camera calibration and marking watershed algorithm to segment the area where the guardrail was located, and by using the Hough transform line detection algorithm, the line features was extracted in the guardrail segmentation area. The guardrail detection was realized by constraining the line detection parameters and the number of line detections. The position of the guardrail was tracked with the Kalman filter under the condition of constant speed model and the feature detection information and position tracking information were combined for decision making and warning. The results show that the average warning accuracy of the system is 89.40%, and this system has certain practical value in engineering sanitation vehicles.

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    Fault diagnosis method of vehicle driving data acquisition devices based on data mining
    ZHANG Hong
    2019, 10(1):  54-59.  doi:10.3969/j.issn.1674-8484.2019.01.006
    Abstract ( 238 )   PDF (1215KB) ( 621 )  

    A fault diagnosis method of vehicles driving cycle data acquisition devices were proposed based on a project sponsored by the China Automotive Test Cycle (CATC) and the Research on Monitoring Technology of Energy Saving and Consumption Reduction for Road Transportation Enterprises in Inner Mongolia (NJ-
    2017-8) by using large data mining technology, a k-means clustering algorithm, an Apriori algorithm association rules, a correlation analysis algorithm, and made an empirical study with a case. The results show that the fault modes of data acquisition devices can be effectively analyzed by k-means algorithm, and the fault diagnosis and causes of data acquisition devices can effectively find out by Apriori algorithm of association rules and correlation between the characteristic parameters of data acquisition devices, which are consistent with the actual maintenance test results. Therefore, this method provides a reference for the operation, maintenance and control of data acquisition devices.

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    Water absorption characteristics of PA6-GF30 door outside handle coating based on Kriging model
    YANG Yan1 CAO Lixiong, LI Liangjun，et al
    2019, 10(1):  60-66.  doi:10.3969/j.issn.1674-8484.2019.01.007
    Abstract ( 180 )   PDF (1755KB) ( 526 )  

    This paper investigated the water absorption characteristics of PA6-GF30 (30% polyamide of glass fibre) for the coating of a vehicle door outside handle, tested material samples with a thickness of 3 mm. Summarized the material regularities about how humidity determines saturated water absorption rate, how
    temperature determines water absorption speed, and how time determines water absorption level. A water absorption mathematical model of PA6-GF30 door outside handle coating was established by using Kriging interpolation method. And an inverse function of service environment was established with a least square method. The precisions were within 5% for tests and calculations. The model was used to predict the water absorption rate and the water absorption condition of the door outside handle coating under different conditions, and was applied to design structure optimally to avoid the non-return problems due to water absorption. A new standard was established for acceleration experiment of water absorption. The results can be used as a reference for further research and design of vehicle parts with similar absorbent materials.

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    Longitudinal and lateral coupling control for autonomous driving vehicle under low adhesion conditions
    GAO Kai, YU Jiawang, ZHANG Jincheng
    2019, 10(1):  67-73.  doi:10.3969/j.issn.1674-8484.2019.01.008
    Abstract ( 271 )   PDF (1975KB) ( 586 )  

    A cascade-longitudinal-horizontal coupling control strategy for vehicles was designed to improve the performance of autonomous vehicles under low attachment conditions. A vehicle dynamics model was established, a longitudinal and lateral motion controller and a longitudinal and lateral front controllers were
    designed to ensure autonomous vehicles can follow the target path; the rear stability controller was designed to calculate the yaw rate and compensate the yaw torque. The following accuracy and stability of vehicles under different adhesion coefficients was analyzed and verified by combining Carsim with Simulink for co-simulation. The results show that the maximum errors of yaw velocity, side slip angle and trajectory following accuracy are reduced by about 38.6%, 45.83% and 5.58%, respectively, before the uncoupled control; the designed controller can effectively improve the following accuracy and stability of the autonomous driving vehicle under low attachment conditions.

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    Protection effect on rear seat female occupant by airbag-belt
    HUANG Jie, LIU Xi, HU Yuanzhi, et al
    2019, 10(1):  74-81.  doi:10.3969/j.issn.1674-8484.2019.01.009
    Abstract ( 212 )   PDF (1956KB) ( 339 )  

    Madymo software was adopted to build a numerical simulation model of a constraint system for rear seat female occupant to investigate the protection effect on rear seat occupant by an airbag-belt. The simulation results were compared with the experiment results to verify the credibility of the simulation model. Based on
    the numerical simulation model, an airbag-belt simulation model was established to analysis the protective effect on the rear female dummy. The protective effect of the airbag-belt was investigated in the two aspects of force limitation level and pretensioner. The results show that the airbag-belt well restrains the rear seat female dummy, and significantly reduces its damage. The airbag-belt also reduces the contact risk between the female dummy’s head and the front seat, and the thorax compression is reduced from 34.8 mm to 29.9 mm. However, the pretensioner, which was added to the airbag-belt, increases the chest compression and is not good for occupant protection.

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    Influences of super-cooled water on PEMFC sub-freezing start-up capability and characteristics
    HUANG Fusen, WANG Shangshang, LI Zhe, et al
    2019, 10(1):  82-87.  doi:10.3969/j.issn.1674-8484.2019.01.010
    Abstract ( 229 )   PDF (2992KB) ( 593 )  

    The transport and freezing characteristics of super-cooled water in proton exchange membrane fuel cell (PEMFC) were studied to find effective sub-freezing start-up strategies and to explore the feasibility of utilizing super-cooled water transport to improve the sub-freezing start-up capability. The water storage capacity and sub-freezing start-up capability of PEMFC were estimated, and the amount of cumulative water during subfreezing start-up process was measured experimentally. The results show that the transport of the super-cooled water in the PEMFC at –10 ℃ and –20 ℃ can effectively expand fuel cell water storage capacity leading to the improvement of the sub-freezing start-up capability. The survival time of the PEMFC can be prolonged by increasing the temperature and reducing the start-up current density and fuel cell active area. However, the randomness of sub-freezing start-up process resulting from the existence of the super-cooled water in the PEMFC will affect the stability of super-cooled water utilization.

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    Automotive Energy Efficiency & Environment Protection
    National standards analysis and energy saving on gear shift indicator for 48-V vehicles
    WANG Xueping, LIU Zhichao* LU Chun, et al
    2019, 10(1):  88-94.  doi:10.3969/j.issn.1674-8484.2019.01.011
    Abstract ( 170 )   PDF (1654KB) ( 441 )  

    Some tests for 48-V vehicles with gear shift indicator (GSI) were carried out, and China national correlation standards were analyzed to investigate the energy-saving of the GSI. After analyzing the acceleration performance of the 48-V system, compared the differences of the actual gear selection, transients
    speed and torque of engines between the 48-V vehicles with or without GSI, under the New European Driving Cycle (NEDC), 4 vehicles were tested under both the normal gear shift and the GSI strategies, according to the national standards, with combining the national standard analysis and tests. The results show that the fuel consumption per 100 km for 48-V vehicle with the GSI is reduced by 0.38 L (which is equivalent to the 5.80% of fuel economy) under the same test conditions and NEDC test cycle. And the fuel consumption reduction from GSI for the 48-V vehicle is greater than that of the conventional one. Therefore, adjusting the engine speed and torque can reduce the fuel consumption. As an emerging energy-saving technology, GSI should be reflected in relevant national standards.

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    Asymptotic analysis of the effect of anode relative humidity on anode pressure drop of proton exchange membrane fuel cell
    LIU Yongfeng, BAI Shijie, PEI Pucheng，et al
    2019, 10(1):  95-100.  doi:10.3969/j.issn.1674-8484.2019.01.012
    Abstract ( 204 )   PDF (1333KB) ( 385 )  

    A model of anode relative humidity – pressure drop (RHPD) was established to explain the relationship between anode relative humidity and anode pressure drop, which based on the same principle of gas molar ratio and local pressure ratio, and considered the influence of the molar flow rate of anode water
    vapor and the water flux of the proton exchange membrane on the anode pressure drop. The RHPD model was imported into FLUENT by user– defined function (UDF) for simulation. A self-developed PEMFC test stand was carried out under working temperature of 60 ℃, cathode relative humidity of 25 %, anode relative humidity of 25 %~75%, respectively. The test results were compared with those of the simulation and the differences were analyzed. The results show that the anode pressure drop decreases with the increase of anode relative humidity, and there is only 0.19 % difference between RHPD model and the experimental data when the anode relative humidity and the cathode relative humidity is respectively 25 % and 75 % at 70 s.

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    Battery state of health (SoH) estimation method and application based on big data
    XIAO Wei, ZHONG Weidong, SHU Xiaonong，et al
    2019, 10(1):  101-105.  doi:10.3969/j.issn.1674-8484.2019.01.013
    Abstract ( 538 )   PDF (1459KB) ( 2158 )  

    A traditional state of health (SoH) estimation method was proposed based on online big data online platform to break through the limitations of SoH estimation methods caused by insufficient battery management system (BMS) storage and computing power. The effects of data discrete characteristics and battery cell
    consistency on the method were studied. The method was integrated into specific big-data platform, and the batteries’ SoH decrease were verified in muti-dimensions such as different vehicle brands, different locations and different time. The results show that this method can effectively estimate SoH of single power battery system and its variation, as well as integrate within other data in muti-dimensions and analyze the big data image of power batteries.

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    Experimental study of extrusion damage tolerance in a NCM Li-ion power battery
    XU Wan, ZHOU Dayong
    2019, 10(1):  106-111.  doi:10.3969/j.issn.1674-8484.2019.01.014
    Abstract ( 225 )   PDF (1339KB) ( 437 )  

    There is a risk of thermal runaway of power battery after collisions of electric vehicles. This paper analyzed extrusion thermal runaway based on a Li-NiCoMnO2 (NCM) power battery to obtain damage tolerance of battery. The cells of battery were extruded in different directions to analyze the extrusion resistance and the
    failure mode of the extrusion thermal runaway. Modules were extruded respectively in two directions to analyze the extrusion failure mode. The results show that the electric cell is more prone to extrusion and failure in length direction than that in width and height directions. The extrusion failure mode is uncertain. The extrusion damage tolerance is 10 mm. The modules are more prone in length direction than that in width and height directions to thermal runaway being consistent with battery cells. The results can provide references for the safety layout design and for the simulation failure determination of power battery packs.

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    Multi-disciplinary integrated optimization design in new architecture advance development of electrical vehicles
    FANG Jian, SHI Guohong
    2019, 10(1):  112-118.  doi:10.3969/j.issn.1674-8484.2019.01.015
    Abstract ( 182 )   PDF (1622KB) ( 607 )  

    A topology design space was established based on the physical dimensions to find a new integrated engineering solution considering different subsystems (body-in-white, chassis and battery structure) for meeting the performance requirements of an electrical vehicle (EV). Compound effects of static and dynamic load were investigated through equivalent static load (ESL) method in density-based topology. Minimum weighted strain energy was defined as the topology optimization objective. The key load path of the EV was find out through interpretation of the topology optimization results. And also the load path was validated in computer aided engineering (CAE) model. The result shows that the vehicle global torsion stiffness and modal of battery in the vehicle can satisfy the requirements, and the battery frame does not deform obviously under 32 km/h side rigid pole impact analysis. The architecture load path of the EV satisfies the requirements of the whole vehicle package and performance and local performance of battery. The integration design is also the optimal and lightweight solution.

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