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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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  • 2020, Vol. 11 No. 2 Published on:30 June 2020 Previous issue    Next issue
    Technologies of control-by-wire and dynamic domain control for automotive chassis
    LI Liang, WANG Xiangyu, CHENG Shuo, CHEN Xiang, HUANG Chao, PING Xianyao, WEI Lingtao
    2020, 11(2):  143-160.  doi:10.3969/j.issn.1674-8484.2020.02.001
    Abstract ( 715 )   PDF (1473KB) ( 2722 )  
     Vehicle dynamics and its control-by-wire technologies are difficult problems in the design of vehicle chassis, which has been an academic research hotspot. The development of intelligent vehicle also puts forward better performance and more urgent requirements for the control-by-wire execution technologies of chassis. This paper introduces the latest development of vehicle dynamics and chassis control-by-wire technologies: In aspect of vehicle dynamics and control technology, introduces the development and research status of vehicle dynamics modeling analysis, dynamics state observation and dynamics stability control strategy; In aspect of the control-by-wire execution technologies of chassis, summarizes the development and research status of braking-by-wire, steering-by-wire and driving-by-wire for autonomous driving. In aspect of the integrated control technologies of vehicle chassis, a concept of chassis dynamics domain control is proposed, and a domain control architecture and coordinated control strategies are introduced systematically. At last, the future research trends of the chassis control-by-wire technologies and dynamic domain technologies are prospected.
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    Research and development of onboard refueling vapor recovery techniques in cars
    HE Ren, LIU Shu
    2020, 11(2):  161-173.  doi:10.3969/j.issn.1674-8484.2020.02.002
    Abstract ( 404 )   PDF (1405KB) ( 691 )  
    With the increasing of vehicle population, the problem of evaporative emissions is becoming severer. Compared with stage Ⅱ systems, the onboard refueling vapor recovery (ORVR) systems have more efficiency, which is conducive to energy conservation and emission reduction. This paper reviewed the development history of onboard vapor recovery techniques to clarify the key technical problems that need to be solved urgently for developing and optimizing onboard refueling vapor recovery systems, and several typical onboard vapor recovery systems were introduced. The research status of filler pipe and carbon canister has been researched. The results indicate that the key point of filler pipe design is the liquid seal, and a reasonable control strategy of canister can reduce the influence of canister desorption on the air-fuel ratio of the engine. Also, the research status of the mathematical model of onboard vapor recovery system has been studied to understand the influencing factors and predict the evaporative emissions. In view of the difference between the operating characteristics of the hybrid electric vehicles engines and the gasoline vehicles engines, the control strategy of canister in hybrid electric vehicles has been discussed. Finally, the problems and future development trends of onboard vapor recovery techniques were summarized. The onboard vapor recovery systems need to be automated to achieve high-precision control to reduce evaporative emissions until the “zero emission” standard is met.
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    Automotive Safety
    Differences in kinematic responses of motorcyclist and occupant in vehicle-motorcycle collisions
    ZOU Tiefang, WANG Guan, HU Lin, WU Hequan, LIU Zhuzi
    2020, 11(2):  174-181.  doi:10.3969/j.issn.1674-8484.2020.02.003
    Abstract ( 353 )   PDF (1263KB) ( 1055 )  
    Some simulation tests and statistical analysis were carried out on 294 groups of vehicles that collided with motorcycles to investigate the differences in the kinematic responses of motorcyclist and rear-seat occupants in motorcycle accidents. Based on the PC-Crash software, 3 vehicle models (sedans, sport utility vehicles (SUVs), and minivans), 7 vehicle speeds, 2 motorcycles speeds and 7 kinds of collision forms with different angles and different directions were used as test variables. The results show that the throw distance, the head collision time, the relative head collision speed, and the head collision angle of motorcyclist and rear-seat occupants have significant differences for 84% of collision forms and for 75% of vehicle models, while the motorcyclist and rear-seat occupants have very significant difference for 12% collision forms. The average throw distance, the relative head collision speed, and the head collision angle of the motorcyclist are higher than those of the rear seat occupant for different collision speeds. And the average head collision time of the rear seat occupants is longer than that of the motorcyclist. The results can provide support for judging the relationship between motorcyclist and rear-seat occupants, and protecting the motorcyclist and rear-seat occupants from injuries.
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    Longitudinal control method of cooperative autopilot vehicle platooning considering time delays
    LI Zhenglei, CHU Duanfeng, HE Yi, LU Liping, WU Chaozhong
    2020, 11(2):  182-188.  doi:10.3969/j.issn.1674-8484.2020.02.004
    Abstract ( 219 )   PDF (1061KB) ( 622 )  
    A longitudinal control method was proposed to improve of robustness for an autopilot cooperative vehicle platooning longitudinal controller considering the time delay of vehicle actuator and the time delay of inter-vehicle communication. A platoon formation model was established with integrating the information including the vehicle position, the spacing deviation between vehicles, the vehicle speeds, and the vehicle accelerations between self-vehicle and the adjacent preceding-vehicle and between self-vehicle and the leadervehicle of the platoon. Boundary conditions of the time delays and the parameters of the PID (proportional, integral, differential) controller were derived based on the Lyapunov stability theory to keep the platoon stability. Simulation analyses were done for a platoon of ten vehicles. The results show that the maximum error is 0.8 m of the deviation of the spaces between vehicles when the controlled vehicle responds with the motion state changing of the adjacent front vehicle and the platoon leader vehicle. Therefore, the rear-end collisions can be avoided when happening a braking deceleration of 0.8 g at the emergency conditions of the platoon leader vehicle.
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    Finite element analysis of the bicycle-helmet protective performances on cyclist head
    ZHANG Yi , HE Wei, JIN Qianqian, PAN Di, HAN Yong
    2020, 11(2):  189-197.  doi:10.3969/j.issn.1674-8484.2020.02.005
    Abstract ( 275 )   PDF (2725KB) ( 315 )  
    Established a finite element model of bicycle helmets and verified its effectiveness to measure its protective performances to the rider’s head according to the drop test in the European Regulation of EN 1078. A real bicycle accident was reconstructed to study the head fracture and the brain injury in cyclist-tovehicle collisions or in cyclist-to-ground collisions. The results show that if the head contacted with the middle of the windshield, the helmeted and unhelmeted difference of the skull fracture risk is less than 1%, with an Abbreviated Injury Scale (AIS) AIS 2+ brain injury risk reducing 4% in the cyclist-to-vehicle collision. While in the cyclist-to-ground collision, the skull fractures risk is reduced by 92% and the AIS2 + brain injury risk is reduced by 17%. The helmet protective performance against the brain injury risk caused by rotational movement is more insufficient than that against the skull fracture risk.
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    Reliability analysis of vehicle disc brake considering dependent failure
    HU Qiguo, YUAN Shuaihui
    2020, 11(2):  198-204.  doi:10.3969/j.issn.1674-8484.2020.02.006
    Abstract ( 154 )   PDF (2080KB) ( 252 )  
    Analyzed the reliability of vehicle disc brake system from the view of dependent failure mechanism to improve the reliability calculation accuracy of automobile disc brake system. Fitted failure functions for both the modal failure and the thermal-mechanical coupling failure, based on a finite element analysis with sample data, by using response function method and back propagation (BP) neural network method. Established a correlation model between different failure modes based on Vine Copula model, to estimate the correlation parameters of the system failure modes and to calculate the system reliability at the moment of 1 000, 2 000, 3 000, 4 000, 5 000 h after the vehicle disc brake starts running. The reliability of the system at different moments was simulated for 105 times by using the Monte Carlo method. The results show that the maximum relative error between the simulated value and the calculated value of the model is 0.29%. Therefore, the model meets the accuracy calculation requirements when calculating the reliability of complex mechanical systems.
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    Active braking hierarchical control algorithm of electric power-assisted brake system
    CHAI Xiaodong, XIA Huaicheng, WANG Zhanchao, QU Zijun
    2020, 11(2):  205-211.  doi:10.3969/j.issn.1674-8484.2020.02.007
    Abstract ( 148 )   PDF (1279KB) ( 203 )  
    An active braking hierarchical control algorithm was proposed for electric power-assisted braking systems to meet the needs for automobile unified active braking. The control method was divided into three layers: the upper, the middle, and the lower layer control. The upper-layer control proposed a feedforward and feedback closed-loop control method of longitudinal deceleration to convert the vehicle's target deceleration into target pressure; The middle-layer control took the braking system pressure-current model as feedforward and the proportion−integration−differentiation (PID) control based on the target pressure segments as feedback to converse the target pressure into the target current of the electric booster power motor; The lower-layer control realized the accurate follow of the target current of the motor through pulse-width modulation (PWM) of the motor input voltages. The test results show that the maximum error of the active deceleration control is ± 0.3 m/s2 with a deceleration response time being less than 300 ms. Therefore, the control algorithm meets the automobile’s needs for unified active braking.
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    Simulation method of rubber suspension in virtual simulation of vehicle collision
    CHEN Xianling, LIU Zhichao, JIANG Binqing, LIU Zhenhai
    2020, 11(2):  212-219.  doi:10.3969/j.issn.1674-8484.2020.02.008
    Abstract ( 282 )   PDF (4526KB) ( 259 )  
    Three simulation modeling methods, namely Beam unit, Shell unit and Solid unit (Beam, Shell and Solid) were adopted respectively based on the failure theory of metal materials to propose an appropriate simulation analysis method to simulate the force condition and failure mode of the car body mounting system in vehicle collision accidents. The simulation analysis was carried out with LS-DYNA software on the force condition of the car body mounting system in the collision, and the simulation accuracy was evaluated in the real car collision tests. The results show that for shear and compression type suspension systems, the simulation analysis method combining Beam and Solid can accurately reflect the force condition and failure mode of the car body suspension system in real car collision accidents. Therefore, the simulation analysis method combining Beam with Solid can be applied to guide the design and development of car body mounting system in the process of car model research and development.
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    Car-cyclist accident scene analysis for autopilot vehicles
    HAN Dashuang, MA Zhixiong, ZHU Xichan
    2020, 11(2):  220-226.  doi:10.3969/j.issn.1674-8484.2020.02.009
    Abstract ( 254 )   PDF (626KB) ( 314 )  
    A vehicle-ride-accident scenario test-condition-library and the corresponding test condition set evaluation model were established to test and evaluate the safety of autopilot in vehicle rider scenarios. 116 vehicle cyclist crashes were screened out. Seven accident scenarios were extracted by using the method of classification tree based on the traffic accident database of a city in Jiangsu Province of China, and based on the National Vehicle Accident In-depth Investigation System (NAIS) database of China. An overall test condition set of the scenarios was generated according to the road and environmental parameters. An evaluation model of vehicle and cyclist crash scene is established by using an analytic hierarchy process (AHP) and a fuzzy comprehensive evaluation method. The results show that as a typical type of accident test condition in China, two-wheeled-vehicle crossing has the highest score and the highest risk on an unobstructed road section in a sunny day with both a passenger-car and a two-wheeled-vehicle driving in a same direction.
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    Energy management strategy for novel dual-mode PHEV system based on DP algorithm
    PANG Hanze, WANG Li, YUAN Yiqing
    2020, 11(2):  227-235.  doi:10.3969/j.issn.1674-8484.2020.02.010
    Abstract ( 255 )   PDF (3007KB) ( 447 )  
    An energy management strategy of a novel dual-mode plug-in hybrid electric vehicle system (DHS) based on Dynamic programming (DP) algorithm was proposed. Equivalent consumption minimization strategy (ECMS) was used to determine the energy distribution in each mode in this strategy. The energy consumptions of the vehicle with this strategy and the previous dynamic and economic rule-based energy management strategy which incorporated ECMS were analyzed under the driving cycles of the New European Driving Cycle (NEDC) and of the Urban Dynamometer Driving Schedule (UDDS) in Matlab/Simulink environment. The simulation results show that by using the DP algorithm strategy, under the NEDC and the UDDS, the all-electric ranges (AER) of vehicles increase by 4.18% and 3.49% respectively, while under the condition of low state of charge (SOC) of the battery, the fuel consumptions decrease by 3.84% and 9.87% respectively. Therefore, the new strategy yields better fuel economy than the other.
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    Lightweight design of power battery compartments based on implicit full parameterization technology
    LIU Ying, ZHU Zhenlin, WANG Dengfeng
    2020, 11(2):  236-242.  doi:10.3969/j.issn.1674-8484.2020.02.011
    Abstract ( 248 )   PDF (1723KB) ( 397 )  
    An implicit full parameterized model was established for lithium-ion power battery compartments of electric vehicles (EV) by using a software platform of SFE Concept to realize EV lightweight design. An optimization process of battery compartments was established by combining an iSight platform. The assembly position of battery hoisting components and wall thickness of key components were taken as design variables, and the overall quality of battery compartment was taken as the optimal-design objective function, while the structural stiffness, strength, the fatigue endurance and the NVH (noise, vibration, harshness) performance were taken as constraint conditions, and using a pointer algorithm. The results showed that the battery mass was reduced by 2.6% after parameter optimization. Therefore, this method has some references for the forwarddesign and development of battery compartment structure.
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    Influences of ash contents in lubricants on durability and soot regeneration of gasoline particulate filter
    SHAO Heng, LI Nan, LIN Yansong, PAN Jinchong, HUA Lun
    2020, 11(2):  243-249.  doi:10.3969/j.issn.1674-8484.2020.02.012
    Abstract ( 249 )   PDF (1200KB) ( 330 )  
    Bench and vehicle tests and a computed tomography (CT) scan were carried out to investigate the influences of ash contents in lubricants on the durability and soot regeneration of gasoline particulate filter (GPF) with the rapid ash accumulation method. It was analyzed that the data obtained from the tests including engine torque, exhaust system back pressure, ash mass, emission effects, and CT profiles. The results show that the higher the ash level in the lubricants, the more ash is produced and the greater arrested proportion of GPF is obtained; the accumulated ash in the GPF can cause the degradation of the engine performance, but the gas emission can be optimized; a small amount of ash can increase soot regeneration speed, but too much or no ash will reduce its regeneration speed.
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    Heat dissipation structure design of battery packs for battery powered AC load haul dump
    YANG Zhongjiong, Cheng Yu, ZHOU Liqiang, YI Shengxian
    2020, 11(2):  250-257.  doi:10.3969/j.issn.1674-8484.2020.02.013
    Abstract ( 133 )   PDF (3563KB) ( 203 )  
    A mathematical model of heat generation and heat dissipation of battery packs was set up for the battery packs of battery powered alternating current (AC) load haul dump to solve the problem of severe heat generation due to its large capacity and a long working time. The heat dissipation effect of battery packs was investigated under the condition of normal cycle and 1 C charge and discharge. And it was also studied that the influence of air outlet position, air outlet size and partition width on the heat dissipation of battery packs. The results show that the maximum temperature of battery packs reaches 63 ℃ when battery packs are under the condition of 1 C continuous charging and discharging. The best heat dissipation is achieved when an air outlet is located on left and right sides of the third floor leading, but that of the other two floors of battery packs has not been improved significantly. The overall heat dissipation of the battery packs is the best and the maximum temperature is reduced by 7.7% when the gap width of the separator is 10 mm and the length of the air outlet is 800 mm.
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