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Computation of the exact time delay margin for vehicle platoon under generic communication topologies

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Journal of Traffic and Transportation engineering(English Edition) 2024年第4期11卷 761-775页

作者： Xu Zhu Maode Yan Panpan Yang Yongtao Liu school of Electronic and Control engineering Chang'an UniversityXi'an 710064China school of automobile Chang'an UniversityXi'an 710064China

Due to the limited bandwidth and transmission congestion of the vehicle platoon's communication,it is inevitable to induce time delay,which significantly degrades the control performance of the vehicle platoon,even resulting in *** paper focuses on analyzing the internal stability under generic communication topologies and presents a method of computing the exact time delay margin(ETDM).The proposed method can offer a necessary and sufficient internal stability condition with no ***,to reduce the analytical complexity and computational burden elegantly,we decompose the closed-loop platoon dynamics into a set of individual subsystems via similarity transformation and matrix *** decomposition approach is applicable for any general communication ***,an explicit formula is deduced to compute the ETDM by surveying the characteristic roots'distribution of all these individual *** is further demonstrated that only the positive purely imaginary roots need to be considered to compute the ***,simulations are conducted to demonstrate the effectiveness of the theoretical claims.

关键词： Vehicle platoon Exact time delay margin Generic communication topologies System decomposition Characteristic roots'distribution

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Identification of the Hammerstein nonlinear system with noisy output measurements

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Control Theory and Technology 2024年第2期22卷 203-212页

作者： Qiming Zha Feng Li Ranran Liu school of Electrical and Information engineering Jiangsu University of TechnologyChangzhou213001JiangsuChina school of automobile and Traffic engineering Jiangsu University of TechnologyChangzhou213001JiangsuChina

In this research, we present a methodology to identify the Hammerstein nonlinear system with noisy output measurements. The Hammerstein system presented is comprised of neural fuzzy model (NFM) as its static nonlinear block and auto-regressive with extra input (ARX) model as its dynamic linear block, and a two-step procedure is accomplished using signal combination. In the first step, in the case of input–output of Gaussian signals, the correlation function-based least squares (CF-LS) technique is utilized to identify the linear block, solving the problem that the intermediate variable connecting nonlinear and linear blocks cannot be measured. In the second step, to improve the identification accuracy of the nonlinear block parameters, an improved particle swarm optimization technique is developed under input–output of random signals. The validity and accuracy of the presented scheme are verified by a numerical simulation and a practical nonlinear process, and the results illustrate that the proposed methodology can identify well the Hammerstein nonlinear system with noisy output measurements.

关键词： Hammerstein nonlinear system Signal combination Auto-regressive with extra input Improved particle swarm optimization

Thin-walled and large-sized magnesium alloy die castings for passenger car cockpit:Application,materials,and manufacture

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China Foundry 2024年第5期21卷 525-545页

作者： Lei Zhan Yu-meng Sun Yang Song Chun-hua Kong Kai Ma Bai-xin Dong Hong-yu Yang Shi-li Shu Feng Qiu school of Automotive engineering Jilin Communication PolytechnicChangchun 130012China Key Laboratory of automobile Materials of Ministry of Education School of Materials Science and EngineeringNanling CampusJilin UniversityChangchun 130025China

In order to effectively reduce energy consumption and increase range mile,new energy vehicles represented by Tesla have greatly aroused the application of integrated magnesium(Mg)alloy die casting technology in ***,the application of Mg alloys in automobiles,especially in automotive cockpit components,is quite extensive,while it has almost disappeared for a period of time due to its relatively high cost,causing a certain degree of information loss in the application technology of Mg alloy parts in *** rapid development of automotive technology has led to a higher requirement for the automotive components compared with those traditional ***,whatever the components themselves,or the Mg alloy materials and die casting process have to face an increasing challenge,needing to be *** addition,owing to its high integration characteristics,the application of Mg alloy die casting technology in large-sized and thin-walled automotive parts has inherent advantages and needs to be expanded ***,it necessitates exploring advance Mg alloys and new product structures and optimizing die casting *** article summarizes and analyzes the development status of thin-walled and large-sized die casting Mg alloy parts in passenger car cockpit and corresponding material selection methods,die casting processes as well as mold design ***,this work will aid researchers in establishing a comprehensive understanding of the manufacture of thin-walled and large-sized die casting Mg alloy parts in automobile *** will also assist them in developing new Mg alloys with improved comprehensive performance and new processes to meet the high requirements for die casting automotive components.

关键词： Mg alloys thin wall large size automotive part die casting

Kinetic model of vibration screening for granular materials based on biological neural network

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Particuology 2024年第5期88卷 98-106页

作者： Zhan Zhao Yan Zhang Fang Qin Mingzhi Jin school of Agricultural engineering Jiangsu UniversityZhenjiang212013China Shandong Academy of Agricultural machinery Sciences Ji'nan250100China

The kinetic model is the theoretical basis for optimizing the structure and operation performance of vibration screening *** this paper,a biological neurodynamic equation and neural connections were established according to the motion and interaction properties of the material under vibration *** material feeding to the screen and the material passing through apertures were considered as excitatory and inhibitory inputs,respectively,and the generated stable neural activity landscape was used to describe the material distribution on the 2D screen *** dynamic process of material vibration screening was simulated using discrete element method(DEM).By comparing the similarity between the material distribution established using biological neural network(BNN)and that obtained using DEM simulation,the optimum coefficients of BNN model under a certain screening parameter were determined,that is,one relationship between the BNN model coefficients and the screening operation parameters was *** screening parameters were randomly selected,and the corresponding relationships were established as a ***,with straw/grain ratio,aperture diameter,inclination angle,vibration strength in normal and tangential directions as inputs,five independent adaptive neuro-fuzzy inference systems(ANFIS)were established to predict the optimum BNN model coefficients,*** training results indicated that ANFIS models had good stability and *** flexibility and adaptability of the proposed BNN method was demonstrated by modeling material distribution under complex feeding conditions such as multiple regions and non-uniform rate.

关键词： Kinetic model Material distribution Vibration screening Biological neural network DEM simulation Adaptive neuro-fuzzy inference systems

Reliability evaluation of IGBT power module on electric vehicle using big data

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Journal of Semiconductors 2024年第5期45卷 50-60页

作者： Li Liu Lei Tang Huaping Jiang Fanyi Wei Zonghua Li Changhong Du Qianlei Peng Guocheng Lu The school of Electrical engineering Chongqing UniversityChongqing 400044China The Deepal automobile Technology Co. Ltd.Chongqing 400023China

There are challenges to the reliability evaluation for insulated gate bipolar transistors(IGBT)on electric vehicles,such as junction temperature measurement,computational and storage *** this paper,a junction temperature estimation approach based on neural network without additional cost is proposed and the lifetime calculation for IGBT using electric vehicle big data is *** direct current(DC)voltage,operation current,switching frequency,negative thermal coefficient thermistor(NTC)temperature and IGBT lifetime are *** the junction temperature(T_(j))is *** the rain flow counting method,the classified irregular temperatures are brought into the life model for the failure *** fatigue accumulation method is then used to calculate the IGBT *** solve the limited computational and storage resources of electric vehicle controllers,the operation of IGBT lifetime calculation is running on a big data *** lifetime is then transmitted wirelessly to electric vehicles as input for neural *** the junction temperature of IGBT under long-term operating conditions can be accurately estimated.A test platform of the motor controller combined with the vehicle big data server is built for the IGBT accelerated aging ***,the IGBT lifetime predictions are derived from the junction temperature estimation by the neural network method and the thermal network *** experiment shows that the lifetime prediction based on a neural network with big data demonstrates a higher accuracy than that of the thermal network,which improves the reliability evaluation of system.

关键词： IGBT junction temperature neural network electric vehicles big data

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A low-frequency pure metal metamaterial absorber with continuously tunable stiffness

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Applied Mathematics and Mechanics(English Edition) 2024年第7期45卷 1209-1224页

作者： Xingzhong WANG Shiteng RUI Shaokun YANG Weiquan ZHANG Fuyin MA school of Mechanical engineering Xi’an Jiaotong UniversityXi’an710049China Xi’an Precision machinery Research Institute Xi’an710077China

To address the incompatibility between high environmental adaptability and deep subwavelength characteristics in conventional local resonance metamaterials,and overcome the deficiencies in the stability of existing active control techniques for band gaps,this paper proposes a design method of pure metal vibration damping metamaterial with continuously tunable stiffness for wideband elastic wave *** design a dual-helix narrow-slit pure metal metamaterial unit,which possesses the triple advantage of high spatial compactness,low stiffness characteristics,and high structural stability,enabling the opening of elastic flexural band gaps in the low-frequency *** to the principle of a sliding rheostat,the introduction of continuously sliding plug-ins into the helical slits enables the continuous variation of the stiffness of the metamaterial unit,achieving a continuously tunable band gap *** successfully extends the effective band gap by more than ten *** experimental results indicate that this metamaterial unit can be used as an additional vibration absorber to absorb the low-frequency vibration energy ***,it advances the metamaterial absorbers from a purely passive narrowband design to a wideband tunable *** pure metal double-helix metamaterials retain the subwavelength properties of metamaterials and are suitable for deployment in harsh ***,by adjusting its stiffness,it substantially broadens the effective band gap range,presenting promising potential applications in various mechanical equipment operating under adverse conditions.

关键词： elastic metamaterial absorber continuously tunable stiffness low-frequency vibration damping variable stiffness design pure metal structure

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Role of bonding filling on HER/OER/ORR multifunctional catalytic activity in transition-metals-doped PdPX(X=S,Se,Te)

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Rare Metals 2024年第10期43卷 5126-5140页

作者： Hai-Hua Huang Wei Li Cheng-Chao Hu Xue-Qin Sun Lin-Guo Lu Xiao-Feng Fan school of Materials Science and engineering Laboratory of Sensitive Materials and DevicesShandong Department of EducationLiaocheng University school of Environmental and Material engineering Yantai University Department of Physics University of Puerto Rico Key Laboratory of automobile Materials (Jilin University) Ministry of EducationCollege of Materials Science and EngineeringJilin University

The development of stable and highly efficien multifunctional electrocatalysts for the hydrogen evolution reaction （HER）,oxygen reduction reaction （ORR） and oxygen evolution reaction （OER） are essential for the efficient conversion and storage of renewable *** significant advantages of single-atom catalysts,such as strong metal slab interactions,unsaturated coordination and efficient atomic utilization,have opened new avenues for designing multifunctional ***,based on density functional theory,a single atom doped PdPX system was designed as a multifunctional electrocatalyst,which demonstrated the synergistic effect between defects and transition metal atoms and led to enhanced catalytic *** results showed that PdPS/PdPSe with P/X vacancy,PdPTe with P/Pd vacancy and Co/Rh/Ir@PdPX exhibited promising HER ***@PdPS（Se）,with an overpotential of 0.56（0.44） V,was predicted to be a promising OER ***,Rh（Ir）@PdPS（Se）catalysts exhibited efficient catalytic properties for ORR Besides,Co@PdPS（Se）,Rh（Ir）@PdPSV（S）,Co@PdP-SeV（Se）and Ir@PdPSV（S）-1exihibited multifunctional catalytic performance with moderate ***,the origin of catalytic activity was revealed by using the crystal orbital Hamilton populations *** a strong adsorption system,proper filling of the anti-bonding state can increase the energy of the system,weaken the adsorption strength,and facilitate the desorption of intermediates Conversely,augmenting bonding states can enhance its adsorption *** findings provide theoretica guidance for the design and fabrication of novel multifunctional electrocatalysts in terms of filling of bondingstate.

关键词： Density functional theory Electrocatalyst Two-dimensional PdPX Water splitting

Research on concrete structure defect repair based on three-dimensional printing

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Frontiers of Structural and Civil engineering 2024年第5期18卷 731-742页

作者： Yang GU Wei LI Xupeng YAO Guangjun LIU school of Mechanical engineering Tongji UniversityShanghai 201804China College of Civil engineering Tongji UniversityShanghai 200092China Shanghai engineering Research Center for Safety Intelligent Control of Building machinery Shanghai 200032China

Quality assurance and maintenance play a crucial role in engineering construction,as they have a significant impact on project *** common issue in concrete structures is the presence of *** enhance the automation level of concrete defect repairs,this study proposes a computer vision-based robotic system,which is based on three-dimensional(3D)printing technology to repair *** system integrates multiple sensors such as light detection and ranging(LiDAR)and *** is utilized to model concrete pipelines and obtain geometric parameters regarding their ***,a convolutional neural network(CNN)is employed with a depth camera to locate defects in concrete ***,a method for coordinate transformation is presented to convert the obtained coordinates into executable ones for a robotic ***,the feasibility of this concrete defect repair method is validated through simulation and experiments.

关键词： concrete defect detection 3D printing deep learning point cloud data

A Detailed Review on License Plate Detection and Recognition Methods

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Journal of Traffic and Transportation engineering(English Edition) 2024年

作者： Zhaokai Li Muhammad Arslan Ghaffar school of automobile， Chang'an University

License Plate Detection and Recognition (LPDR) is crucial for Intelligent Transportation Systems (ITS) to ensure traffic safety and control. LPDR systems are widely used in traffic monitoring， vehicle safety， Vehicle-to-Vehicle (V2V) communication， and reducing traffic accidents. Modern technologies like autonomous driving and traffic optimization require secured V2V communication. Vehicles can use the LPDR system to identify nearby vehicles to communicate safely. With the expansion of applications in daily life， LPDR is facing many challenges. From the simple static camera used at the parking lot entrance， the LPDR systems are currently used for dynamic recognition of vehicle License Plates (LPs)， which is very difficult due to camera movement， camera angle， and distance from the vehicles. Recognizing LPs from different countries using a single algorithm is challenging since different nations use different characters， and LPs comprise multiple lines. For instance， Arabic characters could be more challenging to recognize. This article provides a performance comparison of several real-time tested and simulating LPDR methods. An ideal LPDR system must eliminate the challenges arising from new applications. The LPDR system needs to be designed to work accurately on static/dynamic conditions to develop V2V communication. By categorizing existing well-known LPDR approaches into conventional and machine learning techniques， this review tried to clarify the importance of each type of method. This work aims to review LP detection， character segmentation， and character recognition algorithms and provide guidance on future trends in this area.

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