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Design and Optimization for the Occupant Restraint System of Vehicle Based on a Single Freedom Model

Chinese Journal of Mechanical Engineering 2013年第3期26卷 492-497页

作者： ZHANG Junyuan MA Yue CHEN Chao ZHANG Yan State Key Laboratory of Automobile Simulation and Control Jilin University

Throughout the vehicle crash event, the interactions between vehicle, occupant, restraint system (VOR) are complicated and highly non-linear. CAE and physical tests are the most widely used in vehicle passive safety development, but they can only be done with the detailed 3D model or physical samples. Often some design errors and imperfections are difficult to correct at that time, and a large amount of time will be needed. A restraint system concept design approach which based on single-degree-of-freedom occupant-vehicle model (SDOF) is proposed in this paper. The interactions between the restraint system parameters and the occupant responses in a crash are studied from the view of mechanics and energy. The discrete input and the iterative algorithm method are applied to the SDOF model to get the occupant responses quickly for arbitrary excitations (impact pulse) by MATLAB. By studying the relationships between the ridedown efficiency, the restraint stiffness, and the occupant response, the design principle of the restraint stiffness aiming to reduce occupant injury level during conceptual design is represented. Higher ridedown efficiency means more occupant energy absorbed by the vehicle, but the research result shows that higher ridedown efficiency does not mean lower occupant injury level. A proper restraint system design principle depends on two aspects. On one hand,the restraint system should lead to as high ridedown efficiency as possible, and at the same time, the restraint system should maximize use of the survival space to reduce the occupant deceleration level. As an example, an optimization of a passenger vehicle restraint system is designed by the concept design method above, and the final results are validated by MADYMO, which is the most widely used software in restraint system design, and the sled test. Consequently, a guideline and method for the occupant restraint system concept design is established in this paper.

关键词： vehicle crash occupant restraint system concept design single-degree-of-freedom occupant-vehicle model

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Experimental and numerical investigations of the aerodynamic noise reduction of automotive side view mirrors

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Journal of Hydrodynamics 2018年第4期30卷 642-650页

作者：陈鑫汪硕吴元强李延洋王怀玉 State Key Laboratory of Automobile Simulation and Control Jilin University

This paper studies the aeroacoustics of the side view mirrors by wind tunnel tests and numerical simulations. The mirror is placed on a table in the wind tunnel test. Based on the experiment results, a numerical analysis model is established to analyze the acoustic field in the wake of the side view mirror by the Large Eddy simulation（LES）. The flow field and the noise level of two different side view mirrors are compared in the simulation. It is shown that, with the serration structures applied onto the mirror surface, the turbulence zone and the pressure fluctuation in the wake of the bionic model are improved effectively, which helps its flow control and noise reduction. Meanwhile, as is shown in the noise spectra, when the noise frequency is over 500 Hz, for the bionic mode, the noise is reduced to a lower level than with the original one, which further shows its effectiveness in the noise reduction.

关键词： Aerodynamic noise side view mirror flow field acoustic field bionic noise reduction

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Novel Evaluation Method of Vehicle Suspension Performance Based on Concept of Wheel Turn Center

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Chinese Journal of Mechanical Engineering 2015年第5期28卷 935-944页

作者： WANG Bo GUAN Hsin LU Pingping ZHAN Jun State Key Laboratory of Automobile Simulation and Control Jilin University

The current research of suspension performance evaluation is mixed in the evaluation of vehicle handling and ride comfort. However, it is lack of a direct and independent evaluation method for suspension performance. In this paper, a novel wheel turn center method is proposed to evaluate the suspension performance. This method is based on the concept and application of wheel turn center （WTC） and sprung mass turn center （SPTC）. The vehicle body and each wheel are regarded to be independent rigid bodies and have their own turn centers which reflect respective steering motions and responses. Since the suspension is the link between vehicle body and wheels, the consistence between the sprung mass turn center and the wheel turn center reflects the effect and performance of the suspension system. Firstly, the concept and appropriate calculation method of WTC and SPTC are developed. Then the degree of inconsistence between WTC and SPTC and the time that they achieve consistence, when the vehicle experiences from transient steering to steady steering state, are proposed to evaluate suspension performance. The suspension evaluation tests are conducted under different vehicle velocities and lateral accelerations by using CarSim software. The simulation results show that the inconsistence of steering motion between vehicle body and wheels are mainly at high speeds and low lateral accelerations. Finally, based on the proposed evaluation indexes, the influences of different suspension characteristic parameters on suspension performance and their matches to improve steering coordination are discussed. The proposed wheel turn center method provides a guidance and potential application for suspension evaluation and optimization.

关键词： suspension evaluation wheel turn center sprung mass turn center

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Numerical simulation of the aerodynamic characteristics of heavy-duty trucks through viaduct in crosswind

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Journal of Hydrodynamics 2014年第3期26卷 394-399页

作者：胡兴军秦鹏廖磊郭鹏王靖宇杨博 State Key Laboratory of Automobile Simulation and Control Jilin University

In our numerical simulation the hybrid mesh and the SST k-ω turbulence model are adopted to investigate the variations of the aerodynamic loads and the flow field of heavy-duty trucks while crossing a viaduct with 1.1 m high fences in a crosswind at a velocity of 20 m/s. The results show that, with the protection of a fence, the side force is weakened, and the rolling and yaw moments are strengthened while the truck is crossing the viaduct, which relatively reduces the roll-over safety and the driving stability of the truck. Meanwhile, the direction of the side force changes when the truck enters the viaduct, which makes the roll-over safety and the driving stability the lowest during the process.

关键词： computational fluid dynamics heavy-duty truck crosswind cross viaduct aerodynamic loads flow field

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Corrigendum to "Landscape ecological risk assessment and driving factors analysis based on optimal spatial scales in Luan River Basin, China" [Ecol. Indic. 169 (2024) 112821] (Ecological Indicators (2024) 169, (S1470160X24012780), (10.1016/***.2024.112821))

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Ecological Indicators 2025年 173卷

作者： Yang, Nijuan Zhang, Ting Li, Jianzhu Feng, Ping Yang, Nina State Key Laboratory of Hydraulic Engineering Intelligent Construction and Operation Tianjin University Tianjin300350 China State Key Joint Laboratory of Environmental Simulation and Pollution Control School of Environment Tsinghua University Beijing100084 China

The authors regret "the incorrect use of Figure 1 in the paper. The original figure has now been replaced with the revised figure."[Figure presented] Revised Figure 1 The authors would like to apologise for ...

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Ecological Mechanisms of Carbon Sequestration in Vegetated Coastal Wetland Ecosystem: Exploring the Roles of Biodiversity and Environmental Changes

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Journal of Marine Environmental Engineering 2025年第1期12卷 35-47页

作者： Liu, Lele Du, Ning Eller, Franziska Ye, Siyuan Li, Xiaowen Wei, Jifang Guo, Yaolin Brix, Hans Guo, Weihua Key Laboratory of Ecological Prewarning Protection and Restoration of Bohai Sea Ministry of Natural Resources School of Life Sciences Shandong University 72 Binhai Road Qingdao266237 China Department of Biology Aarhus University Ole Worms Alle 1 Aarhus8000 Denmark Key Laboratory of Coastal Wetland Biogeosciences Qingdao Institute of Marine Geology China Geological Survey Qingdao266000 China School of Environment State Key Joint Laboratory of Environment Simulation and Pollution Control Beijing Normal University Beijing100875 China North China Sea Ecological Center of the Ministry of Natural Resources Qingdao266000 China Ministry of Education Key Laboratory for Biodiversity Science and Ecological Engineering National Observations and Research Station for Wetland Ecosystems of the Yangtze Estuary Institute of Biodiversity Science and Institute of EcoChongming School of Life Sciences Fudan University Shanghai200433 China

Vegetated coastal wetlands, also called blue carbon ecosystems, are significant carbon sinks that play a vital role in global climate change mitigation. Understanding the ecological mechanisms of carbon sequestration in these ecosystems is essential to effectively manage and conserve them. This review focuses on macroecological mechanisms of carbon transfer and microecological mechanisms of carbon stabilization in vegetated coastal wetland ecosystems. Macroecological mechanisms include the horizontal and vertical carbon transport coupled to plant ecophysiology and community diversity, while microecological mechanisms include processes related to soil organic matter dynamics, such as decomposition, stabilization, and mineralization. key scientific issues surrounding these mechanisms include transformation between carbon sink and source, stabilization mechanisms of organic carbon, and environmental effects at multiple time scales. A comprehensive research framework is also presented, which integrates spatial-temporal pattern, macroecological mechanism, microecological mechanism, and ecological engineering. Addressing these key scientific questions within the proposed framework can provide valuable insights into the significant role of biodiversity in blue carbon ecosystems, as well as significant implications for management and conservation of vegetated coastal wetlands under global climate changes. © 2025 Old City Publishing, Inc.

关键词： Ecosystems

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Suppression of Phase Current Ripple and Torque Harmonics in Four-Module PMSM with Asymmetric Mutual Inductance

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IEEE Transactions on Power Electronics 2025年

作者： Liu, Kaiyuan Li, Chi Zheng, Zedong Li, Yongdong Tsinghua University State Key Laboratory of Control and Simulation of Power Systems and Generation Equipments Department of Electrical Engineering Beijing100084 China

In N-module motors, uniform carrier phase shifting (UCPS) by 2π/N between modules can effectively suppress torque harmonics caused by high-frequency switching of power devices. In multi-module motors with fractional-slot concentrated winding, the mutual inductance between adjacent windings is higher than that between non-adjacent windings. Although the conventional UCPS can reduce the torque sideband harmonics synthesized by the four modules, this asymmetric mutual inductance (AMI) paradoxically increases phase current ripple in each sub-module, leading to higher system losses. Aiming at this problem, this paper derives the mathematical model of N-module motor with AMI, analyzes the limitations of the traditional UCPS method that increases the phase current ripple. For different optimization objectives, two carrier phaseshifting angle optimized strategies are proposed to achieve integrated suppression of torque sideband harmonics and intramodule phase current ripples, with a genetic algorithm improving optimization speed. A threshold coefficient is introduced to achieve a tradeoff between phase current ripple and q-axis current harmonics, which can be adjusted to prioritize objectives based on user requirements. To enhance algorithm adaptability, the paper further investigates model variations under uneven torque distribution in sub-healthy states and proposes an improved comprehensive optimization algorithm, limiting torque sideband harmonics and current ripple in both healthy and sub-healthy conditions. Finally, the proposed algorithm is validated experimentally by a four-module permanent magnet synchronous motor. © 2025 IEEE.

关键词： Genetic algorithms

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Investigation of the combustion deterioration of an automotive diesel engine under transient operation

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Science China(Technological Sciences) 2014年第3期57卷 480-488页

作者： ZHANG LongPing LIU ZhongChang TIAN Jing SUN ShiJie State Key Laboratory of Automobile Simulation and Control Jilin University

With increasingly stringent emission regulations and demand for fuel economy by the public,the combustion and emission problems of automotive diesel engines during transient operation have become vital and urgent *** this study,combustion deterioration has been experimentally analyzed using a heavy-duty turbocharged diesel engine running under transient conditions(constant speed and increasing torque).Optimization of the transient combustion process was performed by adjusting the fuel injection *** results indicated that the notable combustion deterioration relative to steady state operation while transient was a function of the delay in the air-supply to the turbocharged engine,and took the form of combustion phasing delay,resulting in rapidly increasing smoke emission and fuel ***,the delay in combustion phasing can be controlled by advancing the fuel injection timing,effectively increasing thermal ***,smoke and NO x emissions increased at the same *** deterioration in combustion phasing can also be improved by increasing injection pressure,resulting in decreased smoke emission while NO x emission *** is worth noting that the effective thermal efficiency first increased and then decreased as fuel injection pressure increased during transient operation.

关键词： diesel engine transient operation combustion deterioration injection parameters combustion optimization

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Daytime Ozone Production Determined by Ratios of Total Volatile Organic Compound Consumption to Nitrogen Oxide Concentrations

ACS ES&T Air

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ACS ES&T Air 2025年第3期2卷 331-342页

作者： Xudong Zheng Qinwen Tan Jie Ren Bin Luo Danlin Song Miao Feng Hefan Liu Yue Qin Yufang Hao Liming Zeng Xin Li Sihua Lu Huabin Dong Shaodong Xie College of Environmental Sciences and Engineering State Key Joint Laboratory of Environmental Simulation and Pollution Control Peking University Beijing 100871 China Chengdu Academy of Environmental Sciences Chengdu Sichuan 610072 China Sichuan Academy of Environmental Policy and Planning Chengdu Sichuan 610041 China College of Environmental Sciences and Engineering State Key Joint Laboratory of Environmental Simulation and Pollution Control Peking University Beijing 100871 China；Laboratory of Atmospheric Chemistry Energy and Environment Research Division Paul Scherrer Institute Villigen 5232 Switzerland

To reduce the uncertainty in analyzing ozone (O3) sensitivities based on observed concentrations of volatile organic compounds (VOCs) and nitrogen dioxide, this study proposed the application of consumed VOC concentrations to establish their nonlinear relationship in the actual atmosphere. These parameters were calculated based on the reaction rates and online observations of VOCs, nitrogen dioxide, and O3concentrations at Deyang, Chengdu, and Meishan in the Chengdu Plain, China, during summer 2019. The nighttime isoprene consumption was maximum at 2.03 ppbv at Meishan. The daytime acetaldehyde consumption was a maximum at 2.68 ppbv at Deyang, possibly due to its higher primary emissions and secondary production and its consumption by both OH radicals and photolysis. When the ratios of the total consumed VOC concentrations to the observed or initial NOx(NOx= NO + NO2) concentrations were 3.51 ppbv ppbv–1or 2.22 ppbv ppbv–1, daytime O3variations reached a maximum of 8.45 ppbv or 7.52 ppbv, respectively. The ratios delineated the VOC-sensitive and NOx-sensitive areas. Over 98% of hourly data were in VOC-sensitive areas at both Chengdu and Meishan, respectively, while over 14% of hourly data belonged to NOx-sensitive areas at Deyang. This provided a more accurate method for assessing real-time O3sensitivity and thus implementing dynamic hierarchical control strategies.

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Aggregation Modeling of System Frequency Response Under Inertia control of Grid-following Direct-drive Wind Turbine

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Dianli Xitong Zidonghua/Automation of Electric Power Systems 2025年第10期49卷 39-48页

作者： Jiang, Chao Yang, Dongfeng Guo, Shujia Liu, Xiaojun Zhou, Shuyu Cao, Zhichong Key Laboratory of Modern Power System Simulation and Control & Renewable Energy Technology Ministry of Education Northeast Electric Power University Jilin132012 China School of Automation and Electrical Engineering Zhejiang University of Science and Technology Hangzhou310023 China State Grid Jilin Electric Power Research Institute Changchun130000 China

The inertia control of grid-following direct-drive wind turbines significantly influences the system frequency response pattern afrer disturbances. However, current research has not clearly identified the dominant response link of direct-drive wind turbines in frequency regulation, while the modeling is too complicated to be suitable for frequency characteristic analysis. Therefore, the linearized models under inertia control are derived for two typical types of direct-drive wind turbines according to the aerodynamic equations, generator models, power control link, and control circuit structure. The fast physical process of current control-boost circuit/stator voltage dynamic loop is clearly understood and reasonably ignored. It is revealed that the two types of direct-drive wind turbines have a common frequency response mechanism which can be described as the cascade effect of the speed regulator-wind rotor motion equation. Furthermore, combined with the frequency response model of synchronous unit, the aggregation model of system frequency response under the inertia control of grid-following direct-drive wind turbines is constructed, and the aggregation model is reduced to a second-order model by the balance truncation method for analytical calculation of frequency extremes. The accuracy and applicability of the aggregation model and its reduced-order model are verified by MATLAB/Simulink simulation, and the influence of control parameters and system states on frequency dynamic characteristics and stability margin is analyzed. © 2025 Automation of Electric Power Systems Press. All rights reserved.

关键词： Electric power system control

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