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

Current Issue

  • 2011, Vol. 2 No. 3 Published on:27 September 2011 Previous issue    Next issue
    Child passenger safety regulation comparison between Europe and United States and the developing trends
    ZHANG Jinhuan, LI Zhigang, HU Jingwen, CHENG Bo
    2011, 2(3):  185-191.  doi:10.3969/j.issn.1674-8484.2011.03.001
    Abstract ( 2344 )   PDF (1152KB) ( 2737 )  
    Regulations such as FMVSS 213 in the USA and ECE R44 in Europe have been widely used for child passenger safety. These two regulations and other relevant references were analyzed and compared, which shows that  ECE R44 is superior to FMVSS 213 in test conditions, child injury criteria, and fixed forms of child restraint systems, and is inferior to FMVSS 213 in child dummies used at present. When stipulating Chinese regulations for child passenger safety, ECE R44 should be focused with the advantages of FMVSS 213 also included. Therefore, the future research in child passenger safety should include the child injury biomechanics, child dummy improvement, seatbelt position determination, and dummy posture control.
    Related Articles | Metrics
    Ecosystems of Electric Vehicle Power Batteries: Performance, Cost and Market
    PIAO Changhao, QIN Dandan, DUAN Zhihui, CHEN Ping, IU Dongqun
    2011, 2(3):  192-197.  doi:10.3969/j.issn.1674-8484.2011.03.002
    Abstract ( 2446 )   PDF (1201KB) ( 2450 )  
     With the energy crisis and environment pollution occurring, energy saving and environmentally friendly electric vehicles (EVs) will gradually be developed in the future. As one of the most important parts of EVs, power batteries are facing various challenges in technology. This paper describes the current state of EV battery industry and the six factors concerned by the EV lithium-ion battery market, including the safety, life span, specific energy, specific power, charging time and cost, which are used to expect the battery technology, cost and market. The results show that battery commoditization will soon be achieved in terms of the current rates of innovation in battery performance and decrease in cost.
    Related Articles | Metrics
    Automotive Safety
    Experimental Investigation on Pressure Gradient of Automotive Hydraulic Anti-lock Braking Systems
    MA Mingxing , HUANG Jinchuan , XU Guomin , GUAN Yancai
    2011, 2(3):  198-205.  doi:10.3969/j.issn.1674-8484.2011.03.003
    Abstract ( 1926 )   PDF (1672KB) ( 2210 )  
     The pressure gradient of the anti-lock braking system (ABS) was experimentally studied using an ABS hydraulic test bench for various conditions including normal brake, on-off brake, and step brake. The pressure gradient was analyzed with the master cylinder pressure and solenoid step pulse width being changed. The results show that for the normal brake, on-off brake, and step brake conditions, the pressure gradient achieves the maximum limit with the master cylinder pressure of 8, 12 and 15 MPa, respectively. The pressure gradient for the pressurization and decompression steps in the pulse width significantly increases with increasing master cylinder pressure. The results provide an important experimental reference for fine-tuning and precise theoretical modelling of ABS wheel cylinder pressure.
    Related Articles | Metrics
    Optimization of front-end styling design for a passenger car based on pedestrian protection
    LV Xiaojiang, WANG Chun, LIU Weiguo, MA Fangwu, WU Chengming, ZHAO Fuquan
    2011, 2(3):  206-211.  doi:10.3969/j.issn.1674-8484.2011.03.004
    Abstract ( 2638 )   PDF (1742KB) ( 2387 )  
    The vehicle front-end styling is a key factor for obtaining better performance of pedestrian protection. Based on the Pedestrian Protection Regulation of the European Commission (Directive 78/2009/EC) and the evaluation procedures of pedestrian protection in European New Car Assessment Program (Euro-NCAP), styling design was optimized for the front-end, including the hood, fender, ventilated cover plate, and bumper  in a passenger car, using CAS (Computer-Aided Styling), in consideration of the requirements of head impact areas and leg impact areas. The results show that the optimized front-end styling effectively controls the impact areas, in favor of the pedestrian protection performance improvement, which provides practice in the styling design for new vehicles.
    Related Articles | Metrics
    Simulation of crashworthiness during front impact and offset impact and vehicle body structure improvement
    JIAN Xiaochun, WANG Xiao
    2011, 2(3):  212-216.  doi:10.3969/j.issn.1674-8484.2011.03.005
    Abstract ( 2187 )   PDF (1362KB) ( 2839 )  
    The crashworthiness during front impact and offset impact was numerically simulated with the vehicle body structure then improved to increase passenger-car safety. A Finite Element Method (FEM) was developed for passenger cars. The experimental methods of C-NCAP (China New Car Assessment Program) and software Hypermesh were used to simulate and analyze the crashworthiness performance, including the deformation sequence of components, the vehicle body acceleration, and the vehicle body invasion, during 40% offset impact and 100% front impact. The structures of some key energy-absorbing components were improved, such as the bumper absorbing box and bumper back-end, with the component strength being increased in the cabin part. The results after improvement show that the maximum intrusion decreases by 15.8% during the 40% offset impact, with the B pillar ensemble acceleration reduced during the 100% front impact.
    Related Articles | Metrics
    Simulation and experimental investigation of auto ignition using microwave plasma
    HUO Na, ZHANG Guixin, ZHANG Feng, LIU Yongxi, Zhang Qing
    2011, 2(3):  217-222.  doi:10.3969/j.issn.1674-8484.2011.03.006
    Abstract ( 1817 )   PDF (1905KB) ( 2019 )  
    The feasibility of microwave plasma employed in auto ignition was demonstrated by simulation design and experiments. The simulation design was implemented using the software of "computer simulation technology" (CST) for a 3-D microwave electromagnetic field. The simulation design shows that when the cylinder piston gets to the top dead centre (TDC), the electric field in the cylinder is stronger than elsewhere and the ignition is generated, with the electric field weakening and the ignition quickly snuffing out with fast TDC deviation. Based on linear distribution of the cylinder, the simulation design imitates the situation of existing four cylinder ignition. The network analyzer tests show that the microwave transfer rate is the largest only in a certain scale with the piston alternating position. The microwave source transfers energy to the linear waveguide with a cylinder through the microwave transmission system. Only in a certain scale range, the electric field in the cylinder is strong enough to generate plasma with auto ignition then produced in the cylinder.
    Related Articles | Metrics
    Lifespan Uniformity for the Battery Pack in the Automotive Application
    WANG Jiayuan, SUN Zechang, WEI Xuezhe, DAI Haifeng
    2011, 2(3):  223-228.  doi:10.3969/j.issn.1674-8484.2011.03.007
    Abstract ( 1908 )   PDF (2008KB) ( 2245 )  
    Battery un-uniformity is a critical problem for the battery pack in the automotive powertrain application. Life model and thermal model were combined with the equivalent circuit model (ECM) to analyze the divergence caused by the un-uniformity decay rate between the cells in the battery pack. The results show different trends of decay for different working conditions. The  temperature which has a close relationship with the polarization process has a significant impact on the decay rate. Both capacity variation and polarization variation should be considered in the cell selection during the battery pack assembly. The method can be applied to the cell selection during the battery pack design and assembly phases.
    Related Articles | Metrics
    Comparative Analysis of Two Kinds of Series-Parallel Power Hybrid Systems
    TAN Di, LUO Yutao, LIU Yanwei
    2011, 2(3):  229-236.  doi:10.3969/j.issn.1674-8484.2011.03.008
    Abstract ( 2229 )   PDF (1676KB) ( 1884 )  
    The topology structures and operating modes of two kinds of Hybrid Power Systems (HPSs) were compared to verify the feasibility of the HPSs and analyze the  operating characteristics, in which one is a typical ‘2-Mode’ parallel-series hybrid system, and the other is a novel Anti-Direction-Dual-Rotor (ADDR) electric motor based system. Simulation was made using a mathematic model of HPS developed in previous work for comparative analysis of the two systems for two typical load conditions, running with low power and accelerating with large power. The results show that both the two systems improve the ability to mechanically transmit power and minimize energy circulation of engine power conversion to electricity. The performance requirement of the ADDR electric motors is lower than that of the traditional ‘1-Mode’ system for the same required condition. Therefore, this HPS control leads to the reduction in the vehicle size, mass, and even the cost, though it is more complicated.
    Related Articles | Metrics
    Adaptive Control of IPMSM Considering Parameter Variation for Electric Vehicle
    WANG Ying-Nan, Uwe SCHAEFER
    2011, 2(3):  237-245.  doi:10.3969/j.issn.1674-8484.2011.03.009
    Abstract ( 2321 )   PDF (1933KB) ( 2696 )  
     An adaptive controller for the interior permanent magnet synchronous machine (IPMSM) was designed to improve the whole performance of an electric vehicle (EV) drive system, with the fact considered that the d-q axis inductances change with the stator currents. The motor parameters were calculated using finite element method (FEM) to realize the minimum loss current control. The controller parameters such as the adaptive law were saved in a 2D-Table for the self-tuning regulator, which assures that the input variables are the measured stator currents. Some parts of the control system were implemented in the field-programmable gate array (FPGA). The results show that the adaptive controllers can satisfactorily suppress the current overshoot and that the system has faster response time since the FPGA also partially replaces the function of the micro-controller.
    References | Related Articles | Metrics
    Simulation of performance and exhaust emission of an engine fuelled with natural gas hydrate blends
    GUO Chao, LI Jun, WANG Wenbin, CHEN Wei
    2011, 2(3):  246-249.  doi:10.3969/j.issn.1674-8484.2011.03.010
    Abstract ( 2074 )   PDF (1611KB) ( 1714 )  
    An engine model was built to analyze the properties and emission characteristics of Natural Gas Hydrate (NGH)-gasoline mixture using GT-Power simulation code based on the original data of the NGH sample test in China. Simulations were carried out on the same engine model with mixtures with six different ratios of NGH-gasoline. The engine with different ratios of NGH-gasoline was investigated on properties of power, economy and emission. The results indicate that  the engine power, torque and fuel consumption rate decrease, while the engine thermal efficiency increases with increasing ratio of NGH in the mixture fuel. The results also show that the CO emission reduces with the NO emission unobviously changed.
    Related Articles | Metrics
    Evaluation of IPMSM Performance Based on the Characteristic Current and Saturated Stator Parameters
    ZHANG Zhouyun , SHI Wei, GONG Jun, YING Hongliang
    2011, 2(3):  250-256.  doi:10.3969/j.issn.1674-8484.2011.03.011
    Abstract ( 1950 )   PDF (2429KB) ( 2747 )  
     Interior permanent magnet synchronous motors (IPMSM) can be widely used in the transmission system of electric vehicles (EVs), which take the advantages of high output torque at low speed, high constant output power at high speed, and high efficiency. Since the magnetic field of IPMSM is designed to be saturated, which makes the output capacity of IPMSM sharply decreases in the high speed range. A method was developed to evaluate the performance of a series of IPMSM using the characteristic current and saturated stator parameters. The method takes maximum torque per Ampere (MTPA) strategy to achieve constant torque control at low speed and constant power speed ratio strategy to achieve constant power control at high speed to meet the requirement of electric vehicles, with output performance of IPMSM regulated by changing the values of the characteristic current compared with the current rates of the power module. Comparative simulation and test results using different prototypes with different parameters validate the accuracy and applicability of the method.
    Related Articles | Metrics
    Intake performance of unthrottled gasoline engines based on fully variable valve systems
    XIE Zongfa, QIN Lei, LIU Yongtian, WANG Zhiming
    2011, 2(3):  257-262.  doi:10.3969/j.issn.1674-8484.2011.03.012
    Abstract ( 3502 )   PDF (1861KB) ( 1998 )  
    For unthrottled gasoline engines, substitution of fully variable valve systems (FVVSs) for throttles is very important for energy saving and emission reduction. A displacement sensor was used to measure the valve lift and intake efficiency of FVVS with an intake flow-meter used to measure the air inflow of the unthrottled gasoline engines. The movement characteristics of the intake valve were analyzed according to the test results, with the adjustments of the intake air volume by FVVS being discussed. The results show that the fully variable valve system enables the maximum valve lift and opening duration to continuously vary in a large range, so the intake air inflow can be controlled though timing and early intake valve closing or late intake valve closing.
    Related Articles | Metrics
    Combustion and emission characteristics of homogeneous charge induced ignition engines
    YU Chao, WANG Jianxin, WANG Zhi, WANG Buyu
    2011, 2(3):  263-270.  doi:10.3969/j.issn.1674-8484.2011.03.013
    Abstract ( 2105 )   PDF (1961KB) ( 2478 )  
     Homogeneous charge induced ignition (HCII) combustion mode can achieve higher thermal efficiency than gasoline SI combustion with lower soot emissions than diesel CI combustion. The combustion characteristics of HCII were investigated on a modified high-pressure common rail single-cylinder diesel engine. The concept of low temperature combustion was used to reduce NOx emissions with a two stage diesel injection strategy used to improve violent combustion of HCII for high  load conditions. The results show that HCII combustion mode has the characteristics of rapid heat release and short combustion duration at a high constant volume ratio. HCII combustion mode leads to complete combustion at richer fuel/air ratios, breaking through the rich limit of direct injection diesel engines for a higher power density. Combined with exhaust gas recirculation (EGR), HCII can achieve low temperature combustion with very low NOx and soot emissions. The two stage diesel injection can reduce the peak heat release rate, thus effectively inhibiting the maximum pressure rise rate.
    Related Articles | Metrics