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Application of networked discrete event system theory on intelligent transportation systems

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Control Theory and Technology 2021年第2期19卷 236-248页

作者： Jiayuan Liang Chaohui Gong Yunfeng Hou Miao Yu Weilin Wang School of Optical-Electrical and Computer Engineering University for Shanghai Science and TechnologyShanghai200093China zhejiang Research Center on smart rail transportation PowerChina Huadong Engineering Corporation LimitedHangzhouZhejiang311225China

The responses of vehicles to the changes in traffic situations inevitably have delays in observing an event and implementing a control command,which often causes fatal *** far,the methods for handling delays are empirical and cannot be mathematically *** eliminate the accidents caused by such delays,in this paper,we develop mathematically provable methods to handle these ***,we use networked discrete event systems to model the process of driving vehicles and present a supervisory controller for handling delay *** method developed in this paper could serve as a new start for modeling and controlling the responsive behaviors of self-driving vehicles in the future.

关键词： Discrete event systems Automata Supervisory control Automated driving systems

Detection using mask adaptive transformers in unmanned aerial vehicle imagery

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Optoelectronics Letters 2025年第2期 113-120页

作者： YE Huibiao FAN Weiming GUO Yuping WANG Xuna ZHOU Dalin China Telecommunication Corporation zhejiang Branch Innovation Center for smart Medical Technologies & Devices Binjiang Institute of Zhejiang University School of Computing University of Portsmouth

Drone photography is an essential building block of intelligent transportation,enabling wide-ranging monitoring,precise positioning,and rapid ***,the high computational cost of transformer-based methods in object detection tasks hinders real-time result transmission in drone target detection ***,we propose mask adaptive transformer (MAT) tailored for such ***,we introduce a structure that supports collaborative token sparsification in support windows,enhancing fault tolerance and reducing computational *** structure comprises two modules:a binary mask strategy and adaptive window self-attention (A-WSA).The binary mask strategy focuses on significant objects in various complex *** A-WSA mechanism is employed to self-attend for balance perfomance and computational cost to select objects and isolate all contextual *** experiments on the challenging CarPK and VisDrone datasets demonstrate the effectiveness and superiority of the proposed ***,it achieves a mean average precision (mAP@0.5) improvement of 1.25%over car detector based on you only look once version 5 (CD-YOLOv5) on the CarPK dataset and a 3.75%average precision(AP@0.5) improvement over cascaded zoom-in detector (CZ Det) on the VisDrone dataset.

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Energy-Efficient Driving Strategy for High-Speed Trains with Considering the Checkpoints

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Chinese Journal of Electronics 2024年第3期33卷 847-858页

作者： Zixuan ZHANG Yuan CAO Shuai SU State Key Laboratory of rail Traffic Control and Safety Beijing Jiaotong University School of Electronic and Information Engineering Beijing Jiaotong University National Engineering Research Center of rail transportation Operation and Control System Beijing Jiaotong University Frontiers Science Center for smart High-speed railway System Beijing Jiaotong University

With rising energy prices and concerns about environmental issues,energy-efficient driving strategies(EEDS) for high-speed trains have received a substantial amount of *** particular,energy-saving schemes play a huge role in reducing the energy and operating costs of *** article studies the EEDS of high-speed trains at a given time.A well-posed model is formulated,in which the constraints of the checkpoints,in addition to the speed limits,vehicle dynamics,and discrete control throttle,are first *** a given control sequence,the Karush-Kuhn-Tucker(KKT) conditions are used to obtain the necessary conditions for an *** to several key equations of the necessary conditions,the checkpoint constraints are *** case studies are conducted based on the data of the Beijing-Shanghai high-speed line to illustrate the effectiveness of the proposed approach.

关键词： Energy consumption Costs Simulation Mathematical models Energy efficiency Vehicle dynamics Optimization

Constrained optimal steady-state control for isolated traffic intersections

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Control Theory and Technology 2014年第1期12卷 84-94页

作者： Jack HADDAD David MAHALEL Ilya IOSLOVICH Per-Olof GUTMAN Technion Sustainable Mobility and Robust transportation (T-smart) Laboratory Technion - Israel Institute of Technology Haifa 32000 Israel

The steady-state or cyclic control problem for a simplified isolated traffic intersection is considered. The optimization problem for the green-red switching sequence is formulated with the help of a discrete-event max-plus model. Two steady-state control problems are formulated： optimal steady-state with green duration constraints, and optimal steady-state control with lost time. In the case when the criterion is a strictly increasing, linear function of the queue lengths, the steady-state control problems can be solved analytically. The structure of constrained optimal steady-state traffic control is revealed, and the effect of the lost time on the optimal solution is illustrated.

关键词： Steady-state control Discrete-event models Isolated traffic intersections

Impacts of communication delay on vehicle platoon string stability and its compensation strategy:A review

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Journal of Traffic and transportation Engineering(English Edition) 2023年第4期10卷 508-529页

作者： Yuqin Zhang Zhihang Xu Zijian Wang Xinpeng Yao Zhigang Xu School of Information Engineering Chang'an UniversityXian 710064China Shandong Key Laboratory of smart transportation Jinan 250000China

Based on the four-element model,this paper reviewed the important research progress in vehicle platoon,compared the advantages and disadvantages of different models in each element longitudinally,and summarized the linkage between each element *** stability criteria are briefly reviewed from three dimensions:local stability,string stability,and traffic flow *** impact of communication delay on vehicle platoon is quantitatively summarized from two aspects:the variation of controller gains and the variation of headway time *** at the inevitable communication delay in vehicle platoon,the compensation strategies are analyzed from five levels.(1)Optimizing the communication network structure.(2)Reconstructing acceleration information.(3)Tuning controller gains.(4)Constructing a multi-branch selection structure.(5)Improving the *** results show that,although these compensation strategies can alleviate the negative impact of communication delay to a certain extent,they also have some defects such as difficulty in adapting to complex and various real road conditions,poor accuracy and real-time performance,insufficient security,and limited application *** is necessary to further improve the accuracy and real-time performance of the device,design an encrypted and scalable network architecture to ensure communication security and adaptability,and conduct further real vehicle testing.

关键词： Traffic engineering Vehicle platoon CACC Communication delay Compensation strategy Stability

Lane-changing trajectory prediction based on multi-task learning

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transportation Safety and Environment 2023年第4期5卷 67-77页

作者： Xianwei Meng Jinjun Tang Fang Yang Zhe Wang smart Transport Key Laboratory of Hunan Province School of Transport and Transportation EngineeringCentral South UniversityChangsha 410075HunanChina

As a complex driving behaviour,lane-changing(LC)behaviour has a great influence on traffic *** lane-changing behaviour often leads to traffic *** studies are currently being conducted to predict lane-change trajectories to minimize ***,most of their models focus on how to optimize input variables without considering the interaction between output *** study proposes an LC trajectory prediction model based on a multi-task deep learning framework to improve driving ***,in this work,the coupling effect of lateral and longitudinal movement is considered in the L.C *** changes in two directions will be modelled separately,and the information interaction is completed under the multi-task learing *** addition,the trajectory fragents are clustered by the driving features,and trajectory type recognition is added to the trajectory prediction framework as an auxiliary ***,the prediction process of lateral and longitudinal trajectory and LC style is completed by long short-term memory(LSTM).The model training and testing are conducted with the data collected by the driving simulator,and the proposed method expresses better performance in LC trjectory prediction compared with several traditional *** results of this study can enhance the trajectory prediction accuracy of advanced driving assistance systems(ADASs)and reduce the traffic accidents caused by lane changes.

关键词： lane-changing behaviour trajectory prediction long short-term memory(LSTM)network multi-task learning trajectory clustering

Condition monitoring and fault diagnosis strategy of railway point machines using vibration signals

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transportation Safety and Environment 2023年第2期5卷 27-37页

作者： Yongkui Sun Yuan Cao Haitao Liu Weifeng Yang Shuai Su National Engineering Research Center of rail transportation Operation and Control System Beijing Jiaotong UniversityBeijing 100044China CRRC Zhuzhou Institute Co Ltd Zhuzhou 412001HunanChina Frontiers Science Center for smart High-speed railway System Beijing Jiaotong UniversityBeijing 100044China

Condition monitoring of railway point machines is important for train operation safety and *** to the fields of mechanical equipment fault detection,this paper proposes a fault detection and identification strategy of railway point machines via vibration signals.A comprehensive feature distilling approach by combining variational mode decomposition(VMD)energy entropy and time-and frequency-domain statistical features is presented,which is more effective than single type of *** optimal set of features was selected with ReliefF,which helps improve the diagnosis *** vector machine(SVM),which is suitable for a small sample,is adopted to realize *** diagnosis accuracy of the proposed method reaches 100%,and its effectiveness is verified by experiment *** this paper,vibration signals are creatively adopted for fault diagnosis of railway point *** presented method can help guide field maintenance staff and also provide reference for fault diagnosis of other equipment.

关键词： railway point machines condition monitoring variational mode decomposition(VMD)energy entropy statistical features

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An efficient approach for the equivalent linearization of frame structures with plastic hinges under nonstationary seismic excitations

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Earthquake Engineering and Engineering Vibration 2024年第3期23卷 677-690页

作者： Huang Huan Li Yingxiong Li Yuyu College of Water Conservancy and Civil Engineering South China Agricultural UniversityGuangzhou 510642China Institute of smart City and Intelligent transportation Southwest Jiaotong UniversityChengdu 611756China

An efficient approach is proposed for the equivalent linearization of frame structures with plastic hinges under nonstationary seismic *** concentrated plastic hinges,described by the Bouc-Wen model,are assumed to occur at the two ends of a linear-elastic beam *** auxiliary differential equations governing the plastic rotational displacements and their corresponding hysteretic displacements are replaced with linearized differential ***,the two sets of equations of motion for the original nonlinear system can be reduced to an expanded-order equivalent linearized equation of motion for equivalent linear *** solve the equation of motion for equivalent linear systems,the nonstationary random vibration analysis is carried out based on the explicit time-domain method with high ***,the proposed treatment method for initial values of equivalent parameters is investigated in conjunction with parallel computing technology,which provides a new way of obtaining the equivalent linear systems at different time *** on the explicit time-domain method,the key responses of interest of the converged equivalent linear system can be calculated through dimension reduction analysis with high *** examples indicate that the proposed approach has high computational efficiency,and shows good applicability to weak nonlinear and medium-intensity nonlinear systems.

关键词： nonstationary random vibration plastic hinge equivalent linearization method explicit time-domain method parallel computation

Analysing taxi customer-search behaviour using Copula-based joint model

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transportation Safety and Environment 2022年第1期4卷 49-62页

作者： Helai Huang Zhenyuan Fang Yiwei Wang Jinjun Tang Xin Fu smart transportation Key Laboratory of Hunan Province School of Traffic and Transportation EngineeringCentral South UniversityChangsha 410075China School of transportation Engineering Chang’an UniversityXi’an 710064China Engineering Research Center of Highway Infrastructure Digitalization Ministry of EducationXi’an 710064China

The drivers of vacant taxis tend to cruise the road network searching new passengers,which leads to additional traffic congestion,air pollution and other *** study introduces a Copula-based joint model to analyse destination selection and route choice behaviour in the customer-search process.A multinomial logit model is used to analyse the destination selection behaviour,and a path size logit model is used to explore the routes choice ***,the joint model applied Copula function is then established to analyse the correlation between these two *** destination customer generation rate,destination distance,route customer generation rate,path travel time,cumulative intersection delay,path size and route length are selected as explanatory *** taxis trajectory data were collected by global positioning system in Xidan District of Beijing City from September 2014 to February *** the log-likelihood,Bayesian information criterion as evaluation indexes to measure the fitting result,the joint model applied Copula function has the highest *** effect of explanatory variables on customer search behaviour is discussed based on the parameter estimation *** results of this study are helpful to understand the customer-search behaviour of taxi drivers to reduce operating costs and improve the efficiency of the taxi operation system.

关键词： customer-search behaviour destination selection route choice model Copula function taxi trajectory data