Autonomous truck platooning,as a novel transportationmode,has attracted significant attention due to its potential to improve transportation efficiency,reduce energy consumption,and lower operational costs.However,thi...Autonomous truck platooning,as a novel transportationmode,has attracted significant attention due to its potential to improve transportation efficiency,reduce energy consumption,and lower operational costs.However,this emerging mode poses new challenges to the dynamic performance of long-span bridges.This study aims to investigate the impact of autonomous truck platoons on the dynamic performance of continuous beam bridges.Using finite element software to construct accurate vehicle-bridge interaction models,we simulated the dynamic response between vehicle platoons and bridge structures.The study systematically evaluated the effects of four key factors—vehicle speed,number of formations,vehicle spacing,and vehicle weight—on mid-span deformation and the dynamic amplification factor of bridges.Taking a long-span continuous beam bridge as the research object and employing orthogonal experimental designmethods,we efficiently explored themulti-factor interactive effects on bridge dynamic response.Research results indicate that vehicle speed is the dominant factor affecting the bridge dynamic coefficient,showing a significant positive correlation.The interaction between vehicle spacing and the number of formations has a substantial impact on the dynamic coefficient,particularly under conditions of high-speed operation,large-scale formations,tight vehicle spacing,and heavy-load multi-factor coupling.These conditions can significantly increase mid-span bridge deformation and the dynamic coefficient,potentially exceeding design live-load standard value in specific scenarios.Based on the experimental results,this study recommends that truck formations strictly control vehicle speed during operation,maintain appropriate vehicle spacing,limit the number of formations,and regulate loading conditions to ensure normal bridge operation and long-termdurability.The research findings provide scientific guidance for optimizing truck formation strategies and ensuring bridge safety.展开更多
A gated service single vacation M/G/1 queue with setup and closedown periods,and different customer arrival rates,is studied in this paper.The probability generating function of the number of systems for customers who...A gated service single vacation M/G/1 queue with setup and closedown periods,and different customer arrival rates,is studied in this paper.The probability generating function of the number of systems for customers who are at the initial moment of service period is analyzed by using a total probability theorem,and the stability condition of the system is obtained.The stationary distribution of the queue length is solved by the regeneration cycle method.The stochastic decomposition of queue length in the steady state is calculated,and the service cycle is obtained.Moreover,classified discussions are established in order to solve the steady-state distribution for the waiting time.The variation of system performance indicators with parameters is analyzed by performing numerical experiments.展开更多
We consider a single server constant retrial queue,in which a state-dependent service policy is used to control the service rate.Customer arrival follows Poisson process,while service time and retrial time are exponen...We consider a single server constant retrial queue,in which a state-dependent service policy is used to control the service rate.Customer arrival follows Poisson process,while service time and retrial time are exponential distributions.Whenever the server is available,it admits the retrial customers into service based on a first-come first-served rule.The service rate adjusts in real-time based on the retrial queue length.An iterative algorithm is proposed to numerically solve the personal optimal problem in the fully observable scenario.Furthermore,we investigate the impact of parameters on the social optimal threshold.The effectiveness of the results is illustrated by two examples.展开更多
In this paper,we introduce a qualitative analysis in order to study the monotonicity and comparability properties of a single-server retrial queueing model with Bernoulli feedback and negative customers,relative to st...In this paper,we introduce a qualitative analysis in order to study the monotonicity and comparability properties of a single-server retrial queueing model with Bernoulli feedback and negative customers,relative to stochastic orderings.Performance measures of such a system are available explicitly,while their forms are cumbersome(these formulas include integrals of Laplace transform,solutions of functional equations,etc.).Therefore,they are not exploitable from the application point of view.To overcome these difficulties,we present stochastic comparison methods in order to get qualitative estimates of these measures.In particular,we prove the monotonicity of the transition operator of the embedded Markov chain.In addition,we establish conditions for which transition operators as well as stationary probabilities,associated with two embedded Markov chains,having the same structure but with different parameters,are comparable relative to the given stochastic orderings.Further,numerical examples are carried out to illustrate the theoretical results.展开更多
The integration of eco-driving and cooperative adaptive cruise control(CACC)with platoon cooperative control(eco-CACC)has emerged as a pivotal approach for improving vehicle energy efficiency.Nonetheless,the prevailin...The integration of eco-driving and cooperative adaptive cruise control(CACC)with platoon cooperative control(eco-CACC)has emerged as a pivotal approach for improving vehicle energy efficiency.Nonetheless,the prevailing eco-CACC implementations still exhibit limitations in fully harnessing the potential energy savings.This can be attributed to the intricate nature of the problem,characterized by its high nonlinearity and non-convexity,making it challenging for conventional solving methods to find solutions.In this paper,a novel strategy based on a decentralized model predictive control(MPC)framework,called predictive ecological cooperative control(PECC),is proposed for vehicle platoon control on hilly roads,aiming to maximize the overall energy efficiency of the platoon.Unlike most existing literature that focuses on suboptimal coordination under predefined leading vehicle trajectories,this strategy employs an approach based on the combination of a long short-term memory network(LSTM)and genetic algorithm(GA)optimization(GA-LSTM)to predict the future speed of the leading vehicle.Notably,a function named the NotchFilter function(NF(?))is introduced to transform the hard state constraints in the eco-CACC problem,thereby alleviating the burden of problem-solving.Finally,through simulation comparisons between PECC and a strategy based on the common eco-CACC modifications,the effectiveness of PECC in improving platoon energy efficiency is demonstrated.展开更多
为研究基于实测头车数据的多车辆跟驰场景下各车辆的跟随效果和排放拟合效果,选取Gipps、LCM、Fritzsche模型进行研究。进行模型标定与多车辆仿真,计算结果显示:Gipps、LCM、Fritzsche模型的CO_(2)、NO_(x)、CO、PN拟合排放误差的均值...为研究基于实测头车数据的多车辆跟驰场景下各车辆的跟随效果和排放拟合效果,选取Gipps、LCM、Fritzsche模型进行研究。进行模型标定与多车辆仿真,计算结果显示:Gipps、LCM、Fritzsche模型的CO_(2)、NO_(x)、CO、PN拟合排放误差的均值分别为2.59%、7.02%和4.07%,均能较好地实现排放仿真。Gipps模型在车速、加速度、VSP(vehicle specific power)分布与排放拟合方面的效果最佳,各跟驰车辆与头车的一致性最好,适用于对跟随效果与排放拟合有要求的多车辆跟驰仿真场景。LCM模型中,后方车辆的加速度、VSP分布与头车相比向数值更低的方向偏移,拟合排放减少,排放误差增加。Fritzsche模型加速度和VSP分布在高、低两个方向上均有偏移,呈三峰分布的特征,高、低峰值对拟合排放的影响有相互抵消的作用,排放误差略有降低。在多车辆跟驰仿真中,各车辆车速、加速度分布与头车保持相似,能够得到较为一致的跟驰车辆VSP分布,获得较好的多车辆排放拟合效果。展开更多
车载网中platoon的稳定性直接决定了道路的安全性.对于platoon编组而言,"稳定"意味着在受到干扰时platoon的结构能保持相对稳定,并且干扰不会被放大.对此,研究platoon在受到干扰时的内部动态特性.通过分析可知,内部间距的变...车载网中platoon的稳定性直接决定了道路的安全性.对于platoon编组而言,"稳定"意味着在受到干扰时platoon的结构能保持相对稳定,并且干扰不会被放大.对此,研究platoon在受到干扰时的内部动态特性.通过分析可知,内部间距的变化符合阻尼运动,并采用SUMO(simulation of urban mobility)仿真软件做了大量实验以证实分析结论.此外,还讨论了不同加速度对欠阻尼的影响,总结出加速度与稳定性之间的关系.展开更多
基金The authors would like to thank the support by“111”Project“Centre on Safety and Intelligent Operation of Sea Bridge(D21013)”.
文摘Autonomous truck platooning,as a novel transportationmode,has attracted significant attention due to its potential to improve transportation efficiency,reduce energy consumption,and lower operational costs.However,this emerging mode poses new challenges to the dynamic performance of long-span bridges.This study aims to investigate the impact of autonomous truck platoons on the dynamic performance of continuous beam bridges.Using finite element software to construct accurate vehicle-bridge interaction models,we simulated the dynamic response between vehicle platoons and bridge structures.The study systematically evaluated the effects of four key factors—vehicle speed,number of formations,vehicle spacing,and vehicle weight—on mid-span deformation and the dynamic amplification factor of bridges.Taking a long-span continuous beam bridge as the research object and employing orthogonal experimental designmethods,we efficiently explored themulti-factor interactive effects on bridge dynamic response.Research results indicate that vehicle speed is the dominant factor affecting the bridge dynamic coefficient,showing a significant positive correlation.The interaction between vehicle spacing and the number of formations has a substantial impact on the dynamic coefficient,particularly under conditions of high-speed operation,large-scale formations,tight vehicle spacing,and heavy-load multi-factor coupling.These conditions can significantly increase mid-span bridge deformation and the dynamic coefficient,potentially exceeding design live-load standard value in specific scenarios.Based on the experimental results,this study recommends that truck formations strictly control vehicle speed during operation,maintain appropriate vehicle spacing,limit the number of formations,and regulate loading conditions to ensure normal bridge operation and long-termdurability.The research findings provide scientific guidance for optimizing truck formation strategies and ensuring bridge safety.
基金supported by the National Natural Science Foundation of China(61973261)the Natural Science Foundation of Jilin Province(20210101151JC).
文摘A gated service single vacation M/G/1 queue with setup and closedown periods,and different customer arrival rates,is studied in this paper.The probability generating function of the number of systems for customers who are at the initial moment of service period is analyzed by using a total probability theorem,and the stability condition of the system is obtained.The stationary distribution of the queue length is solved by the regeneration cycle method.The stochastic decomposition of queue length in the steady state is calculated,and the service cycle is obtained.Moreover,classified discussions are established in order to solve the steady-state distribution for the waiting time.The variation of system performance indicators with parameters is analyzed by performing numerical experiments.
基金supported by the National Natural Science Foundation of China(Grant No.11971486)。
文摘We consider a single server constant retrial queue,in which a state-dependent service policy is used to control the service rate.Customer arrival follows Poisson process,while service time and retrial time are exponential distributions.Whenever the server is available,it admits the retrial customers into service based on a first-come first-served rule.The service rate adjusts in real-time based on the retrial queue length.An iterative algorithm is proposed to numerically solve the personal optimal problem in the fully observable scenario.Furthermore,we investigate the impact of parameters on the social optimal threshold.The effectiveness of the results is illustrated by two examples.
文摘In this paper,we introduce a qualitative analysis in order to study the monotonicity and comparability properties of a single-server retrial queueing model with Bernoulli feedback and negative customers,relative to stochastic orderings.Performance measures of such a system are available explicitly,while their forms are cumbersome(these formulas include integrals of Laplace transform,solutions of functional equations,etc.).Therefore,they are not exploitable from the application point of view.To overcome these difficulties,we present stochastic comparison methods in order to get qualitative estimates of these measures.In particular,we prove the monotonicity of the transition operator of the embedded Markov chain.In addition,we establish conditions for which transition operators as well as stationary probabilities,associated with two embedded Markov chains,having the same structure but with different parameters,are comparable relative to the given stochastic orderings.Further,numerical examples are carried out to illustrate the theoretical results.
基金Supported by National Natural Science Foundation of China(Grant Nos.52172383,51805081)Jiangsu Provincial Postgraduate Research&Practice Innovation Program(Grant No.KYCX22_0196)。
文摘The integration of eco-driving and cooperative adaptive cruise control(CACC)with platoon cooperative control(eco-CACC)has emerged as a pivotal approach for improving vehicle energy efficiency.Nonetheless,the prevailing eco-CACC implementations still exhibit limitations in fully harnessing the potential energy savings.This can be attributed to the intricate nature of the problem,characterized by its high nonlinearity and non-convexity,making it challenging for conventional solving methods to find solutions.In this paper,a novel strategy based on a decentralized model predictive control(MPC)framework,called predictive ecological cooperative control(PECC),is proposed for vehicle platoon control on hilly roads,aiming to maximize the overall energy efficiency of the platoon.Unlike most existing literature that focuses on suboptimal coordination under predefined leading vehicle trajectories,this strategy employs an approach based on the combination of a long short-term memory network(LSTM)and genetic algorithm(GA)optimization(GA-LSTM)to predict the future speed of the leading vehicle.Notably,a function named the NotchFilter function(NF(?))is introduced to transform the hard state constraints in the eco-CACC problem,thereby alleviating the burden of problem-solving.Finally,through simulation comparisons between PECC and a strategy based on the common eco-CACC modifications,the effectiveness of PECC in improving platoon energy efficiency is demonstrated.
文摘为研究基于实测头车数据的多车辆跟驰场景下各车辆的跟随效果和排放拟合效果,选取Gipps、LCM、Fritzsche模型进行研究。进行模型标定与多车辆仿真,计算结果显示:Gipps、LCM、Fritzsche模型的CO_(2)、NO_(x)、CO、PN拟合排放误差的均值分别为2.59%、7.02%和4.07%,均能较好地实现排放仿真。Gipps模型在车速、加速度、VSP(vehicle specific power)分布与排放拟合方面的效果最佳,各跟驰车辆与头车的一致性最好,适用于对跟随效果与排放拟合有要求的多车辆跟驰仿真场景。LCM模型中,后方车辆的加速度、VSP分布与头车相比向数值更低的方向偏移,拟合排放减少,排放误差增加。Fritzsche模型加速度和VSP分布在高、低两个方向上均有偏移,呈三峰分布的特征,高、低峰值对拟合排放的影响有相互抵消的作用,排放误差略有降低。在多车辆跟驰仿真中,各车辆车速、加速度分布与头车保持相似,能够得到较为一致的跟驰车辆VSP分布,获得较好的多车辆排放拟合效果。
文摘车载网中platoon的稳定性直接决定了道路的安全性.对于platoon编组而言,"稳定"意味着在受到干扰时platoon的结构能保持相对稳定,并且干扰不会被放大.对此,研究platoon在受到干扰时的内部动态特性.通过分析可知,内部间距的变化符合阻尼运动,并采用SUMO(simulation of urban mobility)仿真软件做了大量实验以证实分析结论.此外,还讨论了不同加速度对欠阻尼的影响,总结出加速度与稳定性之间的关系.
