Journal of Automotive Safety and Energy

Review on the research and development trends and prospects for argon closed cycle hydrogen engines

CHEN Zhili

2023, 14(1): 1-16. doi:10.3969/j.issn.1674-8484.2023.01.001

Abstract ( 453 )

HTML ( 44)

PDF (3079KB) ( 109 )

Internal combustion engines must operate with zero CO₂ emissions in order to follow the trend towards carbon neutrality and avoid obsolescence in the second half of the 21st century. Furthermore, as the maximum effective thermal efficiency of engines is significantly lower than that of electric or fuel cell vehicles, this will gradually alienate consumers from engine vehicles. Under the background, the argon (Ar) closed cycle hydrogen engine, which was invented by F. M. Lewis in 1948, is back in the spotlight. This is because these engines do not emit CO₂ and because the specific heat ratio of Ar is higher than that of air, the thermal efficiency of an Ar-based engines can be increased significantly and even be comparable to that of electric or fuel cell vehicles. This paper describes in detail the principle of this engine, its development history, advantages and disadvantages, research trends, and research and development topics. Some of the authors’ recent research results are presented. Finally, the relationship between this engine and hydrogen and fuel cell vehicles and its development prospects are discussed.

Figures and Tables | References | Related Articles | Metrics

Effects of the bumper stiffness characteristics on the pedestrian head injuries and the lower extremities injuries

LIU Tianquan, WANG Bingyu, WU He, ZOU Jun, MAO Mingxiang

2023, 14(1): 17-22. doi:10.3969/j.issn.1674-8484.2023.01.002

Abstract ( 311 )

HTML ( 13)

PDF (2170KB) ( 72 )

The effect of bumper stiffness characteristics on the pedestrian head and lower extremity injuries was investigated by using a vehicle Finite Element (FE) analysis model of the National Highway Traffic Safety Administration (NHTSA) of the USA. Some bumper stiffness curves for 20, 40, and 60 km/h crash speeds were obtained by the FE method. The effects of bumper stiffnesses of 0~1.27 MN /m on pedestrian head and lower extremity injuries were conducted by using a multi-body simulation method. The results show that different bumper stiffnesses have almost no effect on the overall kinematic response of pedestrians, but have an extremity effect on the injuries for pedestrian head and lower limb, especially for lower limb injuries. The pedestrian's head maximum contact force is 4.28 kN and 4.26 kN respectively, and the pedestrian's lower leg maximum contact force is 3.94 kN and 9.36 kN respectively, at the stiffness of the bumper contact force-deformation curve corresponding to 20 km/h and 60 km/h. Therefore, the risk of pedestrian lower limb injury increases with the increase of bumper stiffness.

Figures and Tables | References | Related Articles | Metrics

Influencing factors of vehicle damage degree in vehicle-vehicle collision accident at intersection

XIAO Le, ZHOU Hua, WANG Chaojian, LIU Xin

2023, 14(1): 23-30. doi:10.3969/j.issn.1674-8484.2023.01.003

Abstract ( 189 )

HTML ( 11)

PDF (2146KB) ( 143 )

The factors affecting the vehicle to vehicle severity accidents at urban intersections were analyzed by taking the 528 cases of the accidents data selected from the (China) National Automobile Accident In-depth Investigation System (NAIS) as the samples with analyzing time period distribution and the vehicle loss distribution. A bivariate ordered Probit model were established by taking the severity of the casualty and vehicle loss as the dependent variables. The results show that the human factors, the vehicle type, the collision location, the street light and the signal status affect the accident severity significantly; speeding increase the death probability by 15.49%, drunk driving increase the vehicle scrapping probability by 5.92%; No traffic lights escalates the accident severity; collision location affects the vehicle damage severity significantly; and the left side collision causes significant vehicle local deformation is 2.92% higher than the right side. Therefore, considering the vehicle damage state may provide a new perspective for accident factor analysis.

Figures and Tables | References | Related Articles | Metrics

Estimation of vehicle velocities and side-slip angles based on the unscented Kalman filter

LIU Zhaoyong, LIU Wudong, SHAO Weishu, TAN Xiaoqiang, WU Guangqiang

2023, 14(1): 31-37. doi:10.3969/j.issn.1674-8484.2023.01.004

Abstract ( 187 )

HTML ( 8)

PDF (2167KB) ( 415 )

A modular state observer structure of vehicle lateral and longitudinal velocity based on the Unscented Kalman Filter (UKF) was proposed to meet the requirements of vehicle active safety control function and to improve the accuracy of vehicle state observation under strong nonlinear characteristics. The structure used the information of vehicle sensors combined with UKF to observe the longitudinal and lateral velocity, and calculated the vehicle side-slip angle according to the definition of side-slip angle. Numerical simulations and real vehicle experiments were carried out on dry road surfaces. The results show that in the strong nonlinear state, the root mean square error (RMSE) of the simulation results of the UKF-based vehicle side-slip angle estimation is 0.425°, the RMSE of the real vehicle experiment is 0.001°, while the RMSE of the simulation results using the Extended Kalman Filter (EKF) estimation is 0.968°, and the RMSE of the real vehicle experiment is 0.009°. Therefore, the UKF can suppress the influence of vehicle driving interference on observation, so that the observer structure has high observation accuracy and can meet the needs of engineering.

Figures and Tables | References | Related Articles | Metrics

Multi-point intrusion side impact method for the child restraint system and dummy injury

XU Zhe, GAO Guanyu, LIU Cancan, LOU Lei

2023, 14(1): 38-45. doi:10.3969/j.issn.1674-8484.2023.01.005

Abstract ( 122 )

HTML ( 6)

PDF (4629KB) ( 57 )

A multi-point intrusion sled side impact test method was proposed for Child Restraint System (CRS) to reproduce the intrusion on the different parts of door in real vehicle collisions. The method was verified with the real vehicle tests. Using this test method, sled side impact tests were carried out many times to investigate the relationship between the children head injury and the installation modes, the installation directions of the CRS, and the different sizes of child dummies. The results show that the dummy head injury in the ISOFIX+support leg mode is lower than that in the ISOFIX+top tether, the differences of head performance index and head resultant accelerations of the two installation modes are 25.8% and 12.4% respectively; the backward installation is more beneficial to the protection of children's head than forward installation, the differences of head performance index and head resultant accelerations of the two installation directions are 47.8% and 15.9% respectively; the head injury is negatively correlated with the size of the dummy, the larger the dummy, the smaller the head injury.

Figures and Tables | References | Related Articles | Metrics

Man-machine cooperative control strategy of the longitudinal collision avoidances based on the factors of driver, vehicle and road

WANG Xuanyao, CHENG Wangfeng, MA Chengcheng

2023, 14(1): 46-54. doi:10.3969/j.issn.1674-8484.2023.01.006

Abstract ( 133 )

HTML ( 6)

PDF (6169KB) ( 46 )

A man-machine cooperative longitudinal collision avoidance control strategy was proposed to improve the driver’s acceptance of the longitudinal collision avoidance system and improve driving comfort. An improved SeungwukMoon safety distance model was established considering factors such as driver, vehicle, and road surface adhesion conditions, by using a proposed calculation method of minimum following distance. The dynamic safety boundary was determined according to the safety distance model and the time-to-collision parameters. The driver’s control weight was allocated in real-time by using the extension theory to obtain the ideal braking pressure. The results of CarSim/Simulink/AMESim co-simulation was verified by tests. The results show that the driver control weight coefficient of the proposed control strategy is greater than 0.5 with realizing the gradual transfer of control weight. The braking strengths are both less than 0.4g with of a distance between vehicles of less than 8 m at the speed of 30 and 72 km/h. Therefore, this strategy improves ride comfort and vehicle following efficiency.

Figures and Tables | References | Related Articles | Metrics

Modeling and application of road intersections based on digital twins

ZHANG Hong, YU Hailiang, ZHENG Zan, YUAN Shengdong, XIONG Guoqiang

2023, 14(1): 55-61. doi:10.3969/j.issn.1674-8484.2023.01.007

Abstract ( 173 )

HTML ( 5)

PDF (2673KB) ( 244 )

A digital twin traffic management system at road intersection was established to effectively regulate the traffic state of the road network. The core elements and theoretical system of the digital twin model of road intersection were described from six aspects: the theory and the model construction, assembly, integration, management, verification and correction. The operation mechanism of the model and the key technologies of real-time interaction between man, vehicle, road and environment were analyzed from two aspects of the traffic element management and the operation process control. The traffic elements and the intersection operation status were identified in real time based on machine vision; The construction technology was analyzed for the management system based on “virtual control reality”. The results show that this method can accurately identify and simulate the traffic elements and operation state of the road intersection, create a digital window for relevant departments to efficiently adjust the traffic state of the road network, and provide data support for automatic driving.

Figures and Tables | References | Related Articles | Metrics

Active safety evaluation method of advanced driving assistance systems

WANG Yinting, WU Changshui

2023, 14(1): 62-68. doi:10.3969/j.issn.1674-8484.2023.01.008

Abstract ( 187 )

HTML ( 7)

PDF (2574KB) ( 67 )

An method of active safety of advanced driver assistance systems was established to meet the advanced driver assistance systems(ADAS) needs of the active safety of autonomous vehicles based on quantification of margins and uncertainties (QMU), The evaluation system and process applicable to the active safety of autonomous vehicles were developed by combining the basic principle of QMU, using the order relation analysis (G1) methods to determine the weighting factors of the evaluating indicator, and using the fuzzy comprehensive evaluation method to derive the comprehensive evaluation results. The autonomous emergency braking (AEB) function of an automatic vehicle was tested and evaluated in the closed test site. The results show that the evaluation results of the test car speed, acceleration, distance from the target car and steering wheel corner speed are 1.347 3, 6.398 1, 1.079 3 and 1.462 4, and the comprehensive result is 2.783 4, indicating that the proposed evaluation method makes up for the lack of horizontal comparison of single-indicator evaluation results and objectively quantifies the longitudinal evaluation results of active safety of autonomous driving systems.

Figures and Tables | References | Related Articles | Metrics

Functional safety analysis and application design of EMB system for intelligent vehicles

CHENG Jie, ZHENG Kai, QIN Jia, WU Xiaodong

2023, 14(1): 69-79. doi:10.3969/j.issn.1674-8484.2023.01.009

Abstract ( 204 )

HTML ( 5)

PDF (2500KB) ( 1485 )

The functional safety analysis and design of electronic mechanical brake (EMB) system were carried out to improve the reliability of the EMB system based on ISO 26262 standard. Item definition was defined in terms of intelligent vehicles; The hazard analysis and risk assessment (HARA) methodology was applied to obtain the automotive safety integrity level (ASIL) and the system safety goals. By establishing the system safety mechanism, the fault tree (FTA) model was used for safety verification, and the safety goals were decomposed by layers. The failure control module was built based on the safety mechanism of the EMB system. The braking force reconstruction algorithm was designed and the co-simulation model was used to verify the system. The results show that the designed system can meet both functional and safety requirements of the EMB system applied to intelligent vehicles.

Figures and Tables | References | Related Articles | Metrics

An iterative optimization-based predictive control method for eco-driving of unmanned vehicles

LIU Yi, GONG Xinle, TANG Yun, HU Man, MA Jie, QIN Yi, WU Fei, PU Huayan, LUO Jun

2023, 14(1): 80-88. doi:10.3969/j.issn.1674-8484.2023.01.010

Abstract ( 168 )

HTML ( 4)

PDF (2710KB) ( 49 )

A data-driven Iterative Optimization-Based Predictive Control (IOBPC) method for energy saving of unmanned heavy vehicles was proposed. Based on the historical data, the terminal state constraint set and terminal cost function were constructed and updated iteratively. And the approximate treatment of the constraint set and terminal cost function improved the computational efficiency of the algorithm. By learning the correlation between vehicle state trajectory and fuel consumption, the cost function of the optimization algorithm was guaranteed to decrease monotonically and converge in the iterative process, so as to realize the significant improvement of vehicle fuel economy. The results show that the iterative optimization predictive controller makes the vehicle trajectory converged and reduces fuel consumption by about 10.2% after several iterations. Compared with the energy-saving driving strategy based on dynamic programming (DP), the energy-saving effect is further improved. Moreover, it has fewer adjustment parameters and supports real-time solution, which is more conducive to practical application.

Figures and Tables | References | Related Articles | Metrics

Analysis of the influences on dynamic response of relative humidity to PEMFC during loading

LIU Yongfeng, ZHANG Lu, PEI Pucheng, LIU Xintong, YU Yongshuai

2023, 14(1): 89-97. doi:10.3969/j.issn.1674-8484.2023.01.011

Abstract ( 145 )

HTML ( 5)

PDF (3165KB) ( 37 )

A numerical model of dynamic heat transfer was proposed to analyze the influences of relative humidity on the dynamic performance of proton exchange membrane fuel cells (PEMFC), in which the effects of relative humidity and step current on the output voltage were considered, revealing the response law of relative humidity to the water content and current density distribution in the proton exchange membrane (PEM) under the condition of step current change. The dynamic heat transfer (DHT) model was imported into Fluent software through a custom function (UDF) and calculated by the finite volume method. The dynamic response performance of PEMFC was evaluated under the operating temperature of 60 ℃, load current loading amplitude of 5 A, cathode relative humidity of 100%, anode relative humidity of 50% and 100%, respectively. The polarization curves and output voltage responses by the DHT model were compared with the experimental data. The results show that the output voltage and maximum power density with anodic relative humidity of 100% are better than those obtained with anodic relative humidity of 50%. When the anode relative humidity is 100%, the error between the DHT model and the experiment is only 2.18%. The distribution of current density is related to the water content in PEM membrane and the humidity of gas at the anode side. With the increase of relative humidity on the anode side, the distribution uniformity of current density across the membrane decreases. When the relative humidity of anode side are 50% and 100%, the ranges of water content distribution in the membrane before and after loading are 2.9 and 3.1 kmol/m³, 3 and 4.2 kmol/m³, respectively.

Figures and Tables | References | Related Articles | Metrics

Deformation modulus and optimal design of ridge/groove bending radius for the gas diffusion layer

SHI Qitong, FENG Cong, LI Bing, ZHANG Cunman, MING Pingwen

2023, 14(1): 98-105. doi:10.3969/j.issn.1674-8484.2023.01.012

Abstract ( 116 )

HTML ( 6)

PDF (3261KB) ( 113 )

A ridge/groove bending radius optimization design method was proposed to eliminate the stress concentration in the Gas Diffusion Layer (GDL) and to improve the performances and the reliability of Proton Exchange Membrane Fuel Cells (PEMFC). A nonlinear stress-strain analytical solution of the GDL was established based on the beam bending theory and the geometric probability analysis, and verified by the compression tests with some GDL base material of commercial, such as the commoditie of TGP-H-060 and MGL190. The results show that the deformation modulus are 240 kPa for the TGP-H-060 and 420 kPa for the MGL190, so the nonlinear stress-strain model of GDL fit the experimental data properly. The maximum contact pressure on the upper edge of GDL is minimum, the stress concentration phenomenon is eliminated, and the stress distribution uniformity is the best when the ridge/groove bending radius is 340 μm. The value of the deformation modulus affects the degree of non-uniform deformation, but does not change the deformation distribution. Therefore, this optimal design improves the deformation uniformity of the GDL.

Figures and Tables | References | Related Articles | Metrics

Adaptive energy recovery control strategy based on road conditions and driving habits

WU Hao, DING Wenmin, WEI Gaungjie, HU Jun, YOU Daoliang

2023, 14(1): 106-117. doi:10.3969/j.issn.1674-8484.2023.01.013

Abstract ( 186 )

HTML ( 8)

PDF (3047KB) ( 133 )

In order to improve the energy-saving level of electric vehicles, an adaptive energy recovery control strategy that can be adjusted according to external environmental conditions and driving habits was designed by using the method of combining theoretical analysis and actual road test calibration. The energy consumption comparison test was carried out by real vehicles under 3 typical road conditions. The results shows that compared with the fixed-intensity energy recovery strategy, the adaptive sliding energy recovery system can effectively identify the current driving conditions and driving habits and adaptively adjust the vehicle’s sliding energy recovery intensity, which can reduce energy consumption by 4.35%, 3.55% and 0.86% in mountainous, suburban and high-speed road conditions, respectively, which proves that the adaptive energy recovery control strategy proposed can significantly improve the energy saving level of electric vehicles.

Figures and Tables | References | Related Articles | Metrics

Fault diagnosis strategy of electronic control system of active grille shutter

CAO Zijian, WU Changshui, CHEN Li

2023, 14(1): 118-124. doi:10.3969/j.issn.1674-8484.2023.01.014

Abstract ( 193 )

HTML ( 3)

PDF (1890KB) ( 134 )

Active grille shutter (AGS) is an important technical means to improve the fuel economy of automobiles at present. A fault diagnosis strategy applied to its electronic control system was proposed to improve AGS’s reliability and stability. Based on the software architecture of AGS electronic control system, 4 kinds of fault diagnosis mechanisms were designed for fault diagnosis, and corresponding fault protection measures were put forward. An adaptive algorithm of grilles’ boundary position, which can eliminate the error accumulation caused by aging failure of devices and long-term small-angle and high-frequency operation, was designed to reduce the fault false alarm in the diagnosis process. Finally, the fault injection test and fault false alarm test were carried out based on the self-developed bench, and the designed fault diagnosis strategy was verified. The results show that the designed fault diagnosis strategy can quickly and accurately identify and classified the faults, ensuring the error range in normal operation is limited to 5° and improving the reliability of the whole system.

Figures and Tables | References | Related Articles | Metrics

Effects of intake and exhaust pressures on the scavenging process in a poppet-valved two-stroke diesel engine

FU Xueqing, ZHANG Yan, DING Zhanming, ZHUANG Anbang, ZHU Wei, CHENG Jianghua, ZHANG Shuyong

2023, 14(1): 125-132. doi:10.3969/j.issn.1674-8484.2023.01.015

Abstract ( 141 )

HTML ( 5)

PDF (3083KB) ( 45 )

To further investigate the scavenging process of poppet-valved two-stroke engines, the effects of pressure difference in intake and exhaust ports and exhaust gas back pressure on fresh charge flow during the scavenging process of a poppet-valved two-stroke diesel engine with top-entry intake port were investigated through establishing three-dimensional model of the engine at 1 500 r/ min engine speed. The results show that the fresh charge flowing into the cylinder from the left side of intake port forms a reverse tumble. The exhaust gas purity is mainly affected by the fresh charge flowing into the cylinder from the right side of intake port before the reverse tumble front closing to exhaust valve, while it obviously increases after the reverse tumble front reaching exhaust valve. With the pressure difference increasing from 30 to 210 kPa, the exhaust gas purity of the exhaust gas in the left side of exhaust port increases, and that in the right side of exhaust port becomes relatively high at medium-low pressure difference, resulting in that the scavenging quality coefficient is firstly decreased from 0.61 to 0.52 and then increased to 0.56, and finally slightly changed. At fixed pressure difference and higher back pressure ranged from 100 to 190 kPa, exhaust gas purity is close, while scavenging efficiency increases slower, leading to the gradual reduction of scavenging quality coefficient from 0.55 to 0.53.

Figures and Tables | References | Related Articles | Metrics

Current Issue

Journal information

Online journal

Author center

Review center

Contact us