The couple between the power network and the transportation network(TN)is deepening gradually with the increasing penetration rate of electric vehicles(EV),which also poses a great challenge to the traditional voltage...The couple between the power network and the transportation network(TN)is deepening gradually with the increasing penetration rate of electric vehicles(EV),which also poses a great challenge to the traditional voltage control scheme.In this paper,we propose a coordinated voltage control strategy for the active distribution networks considering multiple types of EV.In the first stage,the action of on-load tap changer and capacitor banks,etc.,are determined by optimal power flow calculation,and the node electricity price is also determined based on dynamic time-of-use tariff mechanism.In the second stage,multiple operating scenarios of multiple types of EVs such as cabs,private cars and buses are considered,and the scheduling results of each EV are solved by building an optimization model based on constraints such as queuing theory,Floyd-Warshall algorithm and traffic flow information.In the third stage,the output power of photovoltaic and energy storage systems is fine-tuned in the normal control mode.The charging power of EVs is also regulated in the emergency control mode to reduce the voltage deviation,and the amount of regulation is calculated based on the fair voltage control mode of EVs.Finally,we test the modified IEEE 33-bus distribution system coupled with the 24-bus Beijing TN.The simulation results show that the proposed scheme can mitigate voltage violations well.展开更多
This article presents the research and development of an electric vehicle（EV） in Department of Human-Robotics Saitama Institute of Technology,Japan.Electric mobile systems developed in our laboratory include a conve...This article presents the research and development of an electric vehicle（EV） in Department of Human-Robotics Saitama Institute of Technology,Japan.Electric mobile systems developed in our laboratory include a converted electric automobile,electric wheelchair and personal mobile robot.These mobile systems contribute to realize clean transportation since energy sources and devices from all vehicles,i.e.,batteries and electric motors,does not deteriorate the environment.To drive motors for vehicle traveling,robotic technologies were applied.展开更多
This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle （AV） technologies. AV technologies can decrease the transporta...This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle （AV） technologies. AV technologies can decrease the transportation cost and increase accessibility to low-income households and persons with mobility issues. This emerging technology also has far-reaching applications and implications beyond all current expectations. This paper provides a comprehensive review of the relevant literature and explores a broad spectrum of issues from safety to machine ethics. An indispensable part of a prospective AV development is communication over cars and infrastructure （connected vehicles）. A major knowledge gap exists in AV technology with respect to routing behaviors. Connected- vehicle technology provides a great opportunity to imple- ment an efficient and intelligent routing system. To this end, we propose a conceptual navigation model based on a fleet of AVs that are centrally dispatched over a network seeking system optimization literature on two fronts： （i） This study contributes to the it attempts to shed light on future opportunities as well as possible hurdles associated with AV technology; and （ii） it conceptualizes a navigation model for the AV which leads to highly efficient traffic circulations.展开更多
The dynamics of turning system which is a nonlinear system normally has great impact on the transportation speed of the vehicle having heavy load and large size.The dynamics of turning system depends on control algori...The dynamics of turning system which is a nonlinear system normally has great impact on the transportation speed of the vehicle having heavy load and large size.The dynamics of turning system depends on control algorithm and its implementation,but the existing control algorithms which having high dynamics in the application of heavy transportation vehicle are complex for realization and high hardware requirement.So,the nonlinear turning system is analyzed for improving its dynamics by researching new efficient control algorithm.The models of electromagnetic valve,hydraulic cylinder and turning mechanical part are built individually to get the open-loop model of the turning system following characteristics analyzed.According to the model,a new control algorithm for heavy transportation vehicle which combined PID with Bang-Bang control is presented.Then the close-loop model of turning system is obtained under Matlab/Simulink environment.By comparing the step response of different control algorithms in the same conditions,the new algorithm＇s validity is verified.On the basis of the analysis results,the algorithm is adopted to implement the turning control system by using CAN field bus and PLC controllers.Furthermore,the turning control system has been applied in one type of heavy transportation vehicle.It reduces the response time of turning system from seconds level to 250 ms,and the speed of heavy transportation vehicle increases from 5 km/h to 30 km/h.The application result shows that the algorithm and turning control system have met all the turning requirements.This new type of turning control algorithm proposed is simple in implementation for fast response of nonlinear and large-scale turning system of heavy transportation vehicle.展开更多
In order to solve internal logistics problems of iron and steel works,such as low transportation efficiency of vehicles and high transportation cost,the production process and traditional transportation style of iron ...In order to solve internal logistics problems of iron and steel works,such as low transportation efficiency of vehicles and high transportation cost,the production process and traditional transportation style of iron and steel works were introduced.The internal transport tasks of iron and steel works were grouped based on cluster analysis according to demand time of the transportation.An improved vehicle scheduling model of semi-trailer swap transport among loading nodes and unloading nodes in one task group was set up.The algorithm was designed to solve the vehicle routing problem with simultaneous pick-up and delivery(VRPSPD) problem based on semi-trailer swap transport.A solving program was written by MATLAB software and the method to figure out the optimal path of each grouping was obtained.The dropping and pulling transportation plan of the tractor was designed.And an example of semi-trailer swap transport in iron and steel works was given.The results indicate that semi-trailer swap transport can decrease the numbers of vehicles and drivers by 54.5% and 88.6% respectively compared with decentralized scheduling in iron and steel works,and the total distance traveled reduces by 43.5%.The semi-trailer swap transport can help the iron and steel works develop the production in intension.展开更多
There is a drastic increase experienced in the production of vehicles in recent years across the globe.In this scenario,vehicle classification system plays a vital part in designing Intelligent Transportation Systems(...There is a drastic increase experienced in the production of vehicles in recent years across the globe.In this scenario,vehicle classification system plays a vital part in designing Intelligent Transportation Systems(ITS)for automatic highway toll collection,autonomous driving,and traffic management.Recently,computer vision and pattern recognition models are useful in designing effective vehicle classification systems.But these models are trained using a small number of hand-engineered features derived fromsmall datasets.So,such models cannot be applied for real-time road traffic conditions.Recent developments in Deep Learning(DL)-enabled vehicle classification models are highly helpful in resolving the issues that exist in traditional models.In this background,the current study develops a Lightning Search Algorithm with Deep Transfer Learning-based Vehicle Classification Model for ITS,named LSADTL-VCITS model.The key objective of the presented LSADTL-VCITS model is to automatically detect and classify the types of vehicles.To accomplish this,the presented LSADTL-VCITS model initially employs You Only Look Once(YOLO)-v5 object detector with Capsule Network(CapsNet)as baseline model.In addition,the proposed LSADTL-VCITS model applies LSA with Multilayer Perceptron(MLP)for detection and classification of the vehicles.The performance of the proposed LSADTL-VCITS model was experimentally validated using benchmark dataset and the outcomes were examined under several measures.The experimental outcomes established the superiority of the proposed LSADTL-VCITS model compared to existing approaches.展开更多
Visible Light Communication(VLC)technology is aggressive research for the next generation of communication.Currently,Radio Frequency(RF)communication has crowed spectrum.An Intelligent Transportation System(ITS)has be...Visible Light Communication(VLC)technology is aggressive research for the next generation of communication.Currently,Radio Frequency(RF)communication has crowed spectrum.An Intelligent Transportation System(ITS)has been improved in the communication network for Vehicle-to-Vehicle(V2 V),Vehicle-to-Infrastructure(V2I),and Infrastructure-to-Vehicle(I2V)by using the visible light spectrum instead of the RF spectrum.This article studies the characterization of Line-of-Sight(LOS)optical performance in an Outdoor Wireless Visible Light Communication(OWVLC)system employing a Multiple-Input Multiple-Output(MIMO)technique for I2V communications in ITS regulations.We design the new configuration of the OWVLC-I2V system,which is an alternative approach to communication for I2V system at nighttime.The results show the Channel Impulse Response(CIR)of the LOS links in visible light communication for I2V system in ITS by investigating the receiver on the vehicle moving along the coverage communication area.Furthermore,the OWVLC-I2V system using the MIMO technique depicts the performance of throughput and Bit Error Rate(BER)vs.vehicle speed while the vehicle passes a street light.展开更多
Based on the study on the city transport systems of some typical cities worldwide,this paper put forward that each city transport system has its own development mode,which is influenced by the city development plan,ec...Based on the study on the city transport systems of some typical cities worldwide,this paper put forward that each city transport system has its own development mode,which is influenced by the city development plan,economic development level,traveling vehicle composition etc..When some problems occur,such as the congestions caused by contradiction between the road capacity and vehicle composition,the city transport system may come into temporary maturity period.If the improvement for road system is limited meanwhile,optimized structure of vehicle composition should be an effective solution in this case.With the development of economy-internationalization,the development speed of city transport modernization is rapid.When traveling easiness is conflicting with efficiency,the advantages of public transport system become more obvious.Correspondingly,the superiority of two-wheel vehicles will reappear.Though the important function of two-wheel vehicles for alleviating city traffic problems is obvious,however,their development strategy must be reasonably proposed,and operation regulations must be performed accordingly.展开更多
Resource energy projects present a number of challenges to road authorities who need to formulate a response that allows for the appropriate infrastructure upgrades to be planned,constructed and paid for.Too often the...Resource energy projects present a number of challenges to road authorities who need to formulate a response that allows for the appropriate infrastructure upgrades to be planned,constructed and paid for.Too often the road authority is overwhelmed by individual traffic reports from the proponents without having any reference to a system or process such as a network traffic model on which to test options and cumulative impacts.Yet to set up a functional traffic model will take time,is costly and will need some in-house capability to maintain.At the other end of the scale spread sheet style options are cumbersome to use and often out of date.This paper describes a system that allows the authority to effectively manage the transport task.The latest proposed vehicle movements can be displayed on an active GIS screen and referenced against agreed operational parameters.Various report outputs are also available upon demand.Such a system would assist state and local government authorities to manage the new development generated traffic in Qld.展开更多
Hanoi’s rapid urbanization has led to a surge in private vehicle ownership, particularly motorcycles, amidst inadequate public transportation infrastructure. Despite government efforts, many still prefer motorized tr...Hanoi’s rapid urbanization has led to a surge in private vehicle ownership, particularly motorcycles, amidst inadequate public transportation infrastructure. Despite government efforts, many still prefer motorized transport, citing mobility and safety concerns, exacerbated by insufficient pedestrian infrastructure. This study examines the motivations behind this reliance on motorized vehicles, particularly motorcycles, in Hanoi. Findings reveal safety and convenience as primary factors driving motorized transport use, especially for accessing bus stations. Economic incentives could promote non-motorized travel and public transport adoption. Policy implications highlight the importance of addressing economic factors and improving access infrastructure to manage motorized vehicle reliance and foster sustainable urban mobility in Hanoi.展开更多
The SPMT construction method is a new rapid construction technology of large urban overpass with unblocked traffic,and unstability of SPMT construction method equipment cannot be accurately described due to the concre...The SPMT construction method is a new rapid construction technology of large urban overpass with unblocked traffic,and unstability of SPMT construction method equipment cannot be accurately described due to the concrete beam size,irregular shape and complex transport conditions,which is called kiloton bridge transporting and laying vehicle.The anti-rollover performance of SPMT suspension system is studied,and vehicle side slip angle and load transfer rate(LTR) are regarded as the evaluation indexes.An active suspension adaptive anti-rollover control model of SPMT,in which roll stability affected by the structural parameters and control parameters,is built based on fuzzy PID,and the effectiveness of the control method is verified through real vehicle test.展开更多
This paper presents a high-speed ground effect vehicle(HS-GEV)used specifically for maritime transportation.Given the limitations of current vessels,including various types of watercraft and high-speed boats,in fulfil...This paper presents a high-speed ground effect vehicle(HS-GEV)used specifically for maritime transportation.Given the limitations of current vessels,including various types of watercraft and high-speed boats,in fulfilling of needs in different maritime transportation scenarios,the HS-GEV emerges as a promising solution to address unmet requirements.To efficiently accomplish maritime transportation missions with quickness and safety,several critical features are emphasized,including short take-off on water,flight maneuverability and flight stability.The key techniques required to achieve these features,as well as recent progress highlights,are introduced.Following and promoting these crucial techniques is also suggested as a future step to improve HS-GEV performance.With its predominant features,the HS-GEV holds immense application value in enhancing a high-speed maritime transportation system that aligns with the evolving needs of the real world.展开更多
Accidents involving heavy vehicles might show high mortality rates, so it is important to study ways of reducing them. in this research, it was carried out an analysis of the regulations concerning heavy vehicle braki...Accidents involving heavy vehicles might show high mortality rates, so it is important to study ways of reducing them. in this research, it was carried out an analysis of the regulations concerning heavy vehicle braking systems in Costa Rica. And some opportunities of improving road safety regarding heavy vehicle braking systems were identified. The analysis showed several regulatory weaknesses, among which were found： lack of regulatory controls of vehicles importation, the friction coefficient associated to maximum braking distance is not specified, the use of technologies that guarantee a stable braking is not compulsory, the measuring procedure of braking efficacy in vehicle inspection shows some deficiencies, and little controls have been established on maintenance practices of heavy vehicle fleets.展开更多
The effect of the information delay, which was caused by thc naturc of the distance sensors and wireless communication systems, on the string stability of platoon of automated vehicles was studied. The longitudinal ve...The effect of the information delay, which was caused by thc naturc of the distance sensors and wireless communication systems, on the string stability of platoon of automated vehicles was studied. The longitudinal vehicle dynamics model was built by taking the information delay into consideration, and three typical information frameworks, i.e., leader-predecessor framework （LPF）, multiple-predecessors framework （MPF） and predecessor-successor framework （PSF）, were defined and their related spacing error dynamics models in frequency domain were proposed. The string stability of platoon of automated vehicles was analyzed for the LPF, MPF and PSF, respectively. Meanwhile, the related sufficient string stable conditions were also obtained. The results demonstrate that the string stability can be guaranteed tbr the LPF and PSF with considering the information delay, but the ranges of the control gains of the control laws are smaller than those without considering the information delay. For the MPF, the ＂weak＂ string stability, which can be guaranteed without considering the information delay, cannot be obtained with considering the information delay. The comparative simulations further demonstrate that the LPF shows better string stability, but the PSF shows better string scalable performance.展开更多
Internet of things is deemed as the one of the great revolution after the age of Industrial Revolution.With the development of the communication technology,more and more entities are connected to the communication net...Internet of things is deemed as the one of the great revolution after the age of Industrial Revolution.With the development of the communication technology,more and more entities are connected to the communication network and become one of the elements in the network.Over recent decades,in the area of intelligent transportation,pedestrian and transport infrastructure are connected to the communication network to improve the driving safety and traffic efficiency which is known as the ICV(Intelligent Connected Vehicle).This paper summarizes the global ICV progresses in the past decades and the latest activities of ICV in China,and introduces various aspects regarding the recent development of the ICV,including industry development,spectrum and standard,at the same time.展开更多
The Split Delivery Vehicle Routing Problem (SDVRP) allows customers to be assigned to multiple routes. Two hybrid genetic algorithms are developed for the SDVRP and computational results are given for thirty-two data ...The Split Delivery Vehicle Routing Problem (SDVRP) allows customers to be assigned to multiple routes. Two hybrid genetic algorithms are developed for the SDVRP and computational results are given for thirty-two data sets from previous literature. With respect to the total travel distance and computer time, the genetic algorithm compares favorably versus a column generation method and a two-phase method.展开更多
The Split Delivery Vehicle Routing Problem (SDVRP) is a relaxation of the Capacitated Vehicle Routing Problem (CVRP) where customers may be assigned to multiple routes. A new construction heuristic is developed for th...The Split Delivery Vehicle Routing Problem (SDVRP) is a relaxation of the Capacitated Vehicle Routing Problem (CVRP) where customers may be assigned to multiple routes. A new construction heuristic is developed for the SDVRP and computational results are given for thirty-two data sets from previous literature. With respect to the total travel distance, the construction heuristic compares favorably versus a column generation method and a two-phase method. In addition, the construction heuristic is computationally faster than both previous methods. This construction heuristic could be useful in developing initial solutions, very quickly, for a heuristic, algorithm, or exact procedure.展开更多
For the constant distance spacing policy,the existing researches of the string stability focus on the single-predecessor information framework（SPIF） and predecessor-successor information framework（PSIF）.The resear...For the constant distance spacing policy,the existing researches of the string stability focus on the single-predecessor information framework（SPIF） and predecessor-successor information framework（PSIF）.The research results demonstrated that the string stability could not be guaranteed with the SPIF,and then the PSIF was proposed to resolve this string instability.But the issue,whether the string stability can be guaranteed when applying the PSIF,is still controversial.Meanwhile,most of the previous researches on the string stability were conducted without consideration of the parasitic time delays and lags.In this paper,the practical longitudinal vehicle dynamics model is built with consideration of the parasitic time delays and lags existing in the actuators,sensors or the communication systems.Secondly,the detailed theoretical analysis of string stability in frequency domain is conducted to demonstrate that the classical linear control laws can not ensure the string stability when applying both the symmetrical PSIF（SPSIF） and asymmetrical PSIF（APSIF）.Thirdly,a control law,which adds the position and velocity information of the leading vehicle,is proposed to guarantee string stability for small/medium platoon,and the other control law,which adds the acceleration information of the controlled vehicle,is proposed to guarantee string stability for large platoon as well as small/medium platoon.Finally,the comparative simulation is conducted to confirm the conducted analysis and the proposed control laws.The conducted research completes the means to analyze the string stability in frequency domain,provides the parameters＇ reference for the design and implementation of the practical automatic following controllers,and improves the reliability and stability of the platoon of automatic vehicles.展开更多
All automobile manufacturing companies, Google and Microsoft have announced recently their production of the Fully Automated Autonomous Vehicles (FAAVs), otherwise known as driverless cars. A few FAAVs would be availa...All automobile manufacturing companies, Google and Microsoft have announced recently their production of the Fully Automated Autonomous Vehicles (FAAVs), otherwise known as driverless cars. A few FAAVs would be available in the market as early as in 2018, but mostly in 2020’s. When FAAVs will be available to and become affordable by the average consumers, the implications to the society would be far reaching. The purpose of the paper is to examine the prospect of the popularity of FAAVs and their socio-economic implications to the future society of the World. The paper examines potential impacts on selected sectors of the society including changes in demand for automobiles, its impact on the use of oil, on the environment, and on urban land uses, to list a few.展开更多
基金supported by the Science and Technology Project of North China Electric Power Research Institute,which is“Research on Key Technologies for Power Quality Evaluation and Improvement of New Distribution Network Based on Collaborative Interaction of Source-Network-Load-Storage”(KJZ2022016).
文摘The couple between the power network and the transportation network(TN)is deepening gradually with the increasing penetration rate of electric vehicles(EV),which also poses a great challenge to the traditional voltage control scheme.In this paper,we propose a coordinated voltage control strategy for the active distribution networks considering multiple types of EV.In the first stage,the action of on-load tap changer and capacitor banks,etc.,are determined by optimal power flow calculation,and the node electricity price is also determined based on dynamic time-of-use tariff mechanism.In the second stage,multiple operating scenarios of multiple types of EVs such as cabs,private cars and buses are considered,and the scheduling results of each EV are solved by building an optimization model based on constraints such as queuing theory,Floyd-Warshall algorithm and traffic flow information.In the third stage,the output power of photovoltaic and energy storage systems is fine-tuned in the normal control mode.The charging power of EVs is also regulated in the emergency control mode to reduce the voltage deviation,and the amount of regulation is calculated based on the fair voltage control mode of EVs.Finally,we test the modified IEEE 33-bus distribution system coupled with the 24-bus Beijing TN.The simulation results show that the proposed scheme can mitigate voltage violations well.
文摘This article presents the research and development of an electric vehicle（EV） in Department of Human-Robotics Saitama Institute of Technology,Japan.Electric mobile systems developed in our laboratory include a converted electric automobile,electric wheelchair and personal mobile robot.These mobile systems contribute to realize clean transportation since energy sources and devices from all vehicles,i.e.,batteries and electric motors,does not deteriorate the environment.To drive motors for vehicle traveling,robotic technologies were applied.
文摘This study investigates the challenges and opportunities pertaining to transportation policies that may arise as a result of emerging autonomous vehicle （AV） technologies. AV technologies can decrease the transportation cost and increase accessibility to low-income households and persons with mobility issues. This emerging technology also has far-reaching applications and implications beyond all current expectations. This paper provides a comprehensive review of the relevant literature and explores a broad spectrum of issues from safety to machine ethics. An indispensable part of a prospective AV development is communication over cars and infrastructure （connected vehicles）. A major knowledge gap exists in AV technology with respect to routing behaviors. Connected- vehicle technology provides a great opportunity to imple- ment an efficient and intelligent routing system. To this end, we propose a conceptual navigation model based on a fleet of AVs that are centrally dispatched over a network seeking system optimization literature on two fronts： （i） This study contributes to the it attempts to shed light on future opportunities as well as possible hurdles associated with AV technology; and （ii） it conceptualizes a navigation model for the AV which leads to highly efficient traffic circulations.
基金supported by National Hi-tech Research and Development Program of China (863 Program, Grant No. 2007AA04Z215)Research Fund for the Doctoral Program of Higher Education of China (Grant No. 20111102110007)
文摘The dynamics of turning system which is a nonlinear system normally has great impact on the transportation speed of the vehicle having heavy load and large size.The dynamics of turning system depends on control algorithm and its implementation,but the existing control algorithms which having high dynamics in the application of heavy transportation vehicle are complex for realization and high hardware requirement.So,the nonlinear turning system is analyzed for improving its dynamics by researching new efficient control algorithm.The models of electromagnetic valve,hydraulic cylinder and turning mechanical part are built individually to get the open-loop model of the turning system following characteristics analyzed.According to the model,a new control algorithm for heavy transportation vehicle which combined PID with Bang-Bang control is presented.Then the close-loop model of turning system is obtained under Matlab/Simulink environment.By comparing the step response of different control algorithms in the same conditions,the new algorithm＇s validity is verified.On the basis of the analysis results,the algorithm is adopted to implement the turning control system by using CAN field bus and PLC controllers.Furthermore,the turning control system has been applied in one type of heavy transportation vehicle.It reduces the response time of turning system from seconds level to 250 ms,and the speed of heavy transportation vehicle increases from 5 km/h to 30 km/h.The application result shows that the algorithm and turning control system have met all the turning requirements.This new type of turning control algorithm proposed is simple in implementation for fast response of nonlinear and large-scale turning system of heavy transportation vehicle.
基金Project(70671108) supported by the National Natural Science Foundation of China
文摘In order to solve internal logistics problems of iron and steel works,such as low transportation efficiency of vehicles and high transportation cost,the production process and traditional transportation style of iron and steel works were introduced.The internal transport tasks of iron and steel works were grouped based on cluster analysis according to demand time of the transportation.An improved vehicle scheduling model of semi-trailer swap transport among loading nodes and unloading nodes in one task group was set up.The algorithm was designed to solve the vehicle routing problem with simultaneous pick-up and delivery(VRPSPD) problem based on semi-trailer swap transport.A solving program was written by MATLAB software and the method to figure out the optimal path of each grouping was obtained.The dropping and pulling transportation plan of the tractor was designed.And an example of semi-trailer swap transport in iron and steel works was given.The results indicate that semi-trailer swap transport can decrease the numbers of vehicles and drivers by 54.5% and 88.6% respectively compared with decentralized scheduling in iron and steel works,and the total distance traveled reduces by 43.5%.The semi-trailer swap transport can help the iron and steel works develop the production in intension.
文摘There is a drastic increase experienced in the production of vehicles in recent years across the globe.In this scenario,vehicle classification system plays a vital part in designing Intelligent Transportation Systems(ITS)for automatic highway toll collection,autonomous driving,and traffic management.Recently,computer vision and pattern recognition models are useful in designing effective vehicle classification systems.But these models are trained using a small number of hand-engineered features derived fromsmall datasets.So,such models cannot be applied for real-time road traffic conditions.Recent developments in Deep Learning(DL)-enabled vehicle classification models are highly helpful in resolving the issues that exist in traditional models.In this background,the current study develops a Lightning Search Algorithm with Deep Transfer Learning-based Vehicle Classification Model for ITS,named LSADTL-VCITS model.The key objective of the presented LSADTL-VCITS model is to automatically detect and classify the types of vehicles.To accomplish this,the presented LSADTL-VCITS model initially employs You Only Look Once(YOLO)-v5 object detector with Capsule Network(CapsNet)as baseline model.In addition,the proposed LSADTL-VCITS model applies LSA with Multilayer Perceptron(MLP)for detection and classification of the vehicles.The performance of the proposed LSADTL-VCITS model was experimentally validated using benchmark dataset and the outcomes were examined under several measures.The experimental outcomes established the superiority of the proposed LSADTL-VCITS model compared to existing approaches.
基金supported in part by the Ministry of Higher Education,Science and Research Innovation of Thailand.
文摘Visible Light Communication(VLC)technology is aggressive research for the next generation of communication.Currently,Radio Frequency(RF)communication has crowed spectrum.An Intelligent Transportation System(ITS)has been improved in the communication network for Vehicle-to-Vehicle(V2 V),Vehicle-to-Infrastructure(V2I),and Infrastructure-to-Vehicle(I2V)by using the visible light spectrum instead of the RF spectrum.This article studies the characterization of Line-of-Sight(LOS)optical performance in an Outdoor Wireless Visible Light Communication(OWVLC)system employing a Multiple-Input Multiple-Output(MIMO)technique for I2V communications in ITS regulations.We design the new configuration of the OWVLC-I2V system,which is an alternative approach to communication for I2V system at nighttime.The results show the Channel Impulse Response(CIR)of the LOS links in visible light communication for I2V system in ITS by investigating the receiver on the vehicle moving along the coverage communication area.Furthermore,the OWVLC-I2V system using the MIMO technique depicts the performance of throughput and Bit Error Rate(BER)vs.vehicle speed while the vehicle passes a street light.
文摘Based on the study on the city transport systems of some typical cities worldwide,this paper put forward that each city transport system has its own development mode,which is influenced by the city development plan,economic development level,traveling vehicle composition etc..When some problems occur,such as the congestions caused by contradiction between the road capacity and vehicle composition,the city transport system may come into temporary maturity period.If the improvement for road system is limited meanwhile,optimized structure of vehicle composition should be an effective solution in this case.With the development of economy-internationalization,the development speed of city transport modernization is rapid.When traveling easiness is conflicting with efficiency,the advantages of public transport system become more obvious.Correspondingly,the superiority of two-wheel vehicles will reappear.Though the important function of two-wheel vehicles for alleviating city traffic problems is obvious,however,their development strategy must be reasonably proposed,and operation regulations must be performed accordingly.
文摘Resource energy projects present a number of challenges to road authorities who need to formulate a response that allows for the appropriate infrastructure upgrades to be planned,constructed and paid for.Too often the road authority is overwhelmed by individual traffic reports from the proponents without having any reference to a system or process such as a network traffic model on which to test options and cumulative impacts.Yet to set up a functional traffic model will take time,is costly and will need some in-house capability to maintain.At the other end of the scale spread sheet style options are cumbersome to use and often out of date.This paper describes a system that allows the authority to effectively manage the transport task.The latest proposed vehicle movements can be displayed on an active GIS screen and referenced against agreed operational parameters.Various report outputs are also available upon demand.Such a system would assist state and local government authorities to manage the new development generated traffic in Qld.
文摘Hanoi’s rapid urbanization has led to a surge in private vehicle ownership, particularly motorcycles, amidst inadequate public transportation infrastructure. Despite government efforts, many still prefer motorized transport, citing mobility and safety concerns, exacerbated by insufficient pedestrian infrastructure. This study examines the motivations behind this reliance on motorized vehicles, particularly motorcycles, in Hanoi. Findings reveal safety and convenience as primary factors driving motorized transport use, especially for accessing bus stations. Economic incentives could promote non-motorized travel and public transport adoption. Policy implications highlight the importance of addressing economic factors and improving access infrastructure to manage motorized vehicle reliance and foster sustainable urban mobility in Hanoi.
基金Supported by the National Natural Science Foundation of China(No.51405424,51675461,11673040)Hebei Province Natural Science Foundation of China(No.E2012203071)
文摘The SPMT construction method is a new rapid construction technology of large urban overpass with unblocked traffic,and unstability of SPMT construction method equipment cannot be accurately described due to the concrete beam size,irregular shape and complex transport conditions,which is called kiloton bridge transporting and laying vehicle.The anti-rollover performance of SPMT suspension system is studied,and vehicle side slip angle and load transfer rate(LTR) are regarded as the evaluation indexes.An active suspension adaptive anti-rollover control model of SPMT,in which roll stability affected by the structural parameters and control parameters,is built based on fuzzy PID,and the effectiveness of the control method is verified through real vehicle test.
基金supported by the Fundamental Research Funds for the Central Universities[No.ILA 22012]CARDC Fundamental and Frontier Technology Research Found[No.PJD20200210].
文摘This paper presents a high-speed ground effect vehicle(HS-GEV)used specifically for maritime transportation.Given the limitations of current vessels,including various types of watercraft and high-speed boats,in fulfilling of needs in different maritime transportation scenarios,the HS-GEV emerges as a promising solution to address unmet requirements.To efficiently accomplish maritime transportation missions with quickness and safety,several critical features are emphasized,including short take-off on water,flight maneuverability and flight stability.The key techniques required to achieve these features,as well as recent progress highlights,are introduced.Following and promoting these crucial techniques is also suggested as a future step to improve HS-GEV performance.With its predominant features,the HS-GEV holds immense application value in enhancing a high-speed maritime transportation system that aligns with the evolving needs of the real world.
文摘Accidents involving heavy vehicles might show high mortality rates, so it is important to study ways of reducing them. in this research, it was carried out an analysis of the regulations concerning heavy vehicle braking systems in Costa Rica. And some opportunities of improving road safety regarding heavy vehicle braking systems were identified. The analysis showed several regulatory weaknesses, among which were found： lack of regulatory controls of vehicles importation, the friction coefficient associated to maximum braking distance is not specified, the use of technologies that guarantee a stable braking is not compulsory, the measuring procedure of braking efficacy in vehicle inspection shows some deficiencies, and little controls have been established on maintenance practices of heavy vehicle fleets.
基金Project(20070006011) supported by the Doctoral Foundation of Ministry of Education of China
文摘The effect of the information delay, which was caused by thc naturc of the distance sensors and wireless communication systems, on the string stability of platoon of automated vehicles was studied. The longitudinal vehicle dynamics model was built by taking the information delay into consideration, and three typical information frameworks, i.e., leader-predecessor framework （LPF）, multiple-predecessors framework （MPF） and predecessor-successor framework （PSF）, were defined and their related spacing error dynamics models in frequency domain were proposed. The string stability of platoon of automated vehicles was analyzed for the LPF, MPF and PSF, respectively. Meanwhile, the related sufficient string stable conditions were also obtained. The results demonstrate that the string stability can be guaranteed tbr the LPF and PSF with considering the information delay, but the ranges of the control gains of the control laws are smaller than those without considering the information delay. For the MPF, the ＂weak＂ string stability, which can be guaranteed without considering the information delay, cannot be obtained with considering the information delay. The comparative simulations further demonstrate that the LPF shows better string stability, but the PSF shows better string scalable performance.
文摘Internet of things is deemed as the one of the great revolution after the age of Industrial Revolution.With the development of the communication technology,more and more entities are connected to the communication network and become one of the elements in the network.Over recent decades,in the area of intelligent transportation,pedestrian and transport infrastructure are connected to the communication network to improve the driving safety and traffic efficiency which is known as the ICV(Intelligent Connected Vehicle).This paper summarizes the global ICV progresses in the past decades and the latest activities of ICV in China,and introduces various aspects regarding the recent development of the ICV,including industry development,spectrum and standard,at the same time.
文摘The Split Delivery Vehicle Routing Problem (SDVRP) allows customers to be assigned to multiple routes. Two hybrid genetic algorithms are developed for the SDVRP and computational results are given for thirty-two data sets from previous literature. With respect to the total travel distance and computer time, the genetic algorithm compares favorably versus a column generation method and a two-phase method.
文摘The Split Delivery Vehicle Routing Problem (SDVRP) is a relaxation of the Capacitated Vehicle Routing Problem (CVRP) where customers may be assigned to multiple routes. A new construction heuristic is developed for the SDVRP and computational results are given for thirty-two data sets from previous literature. With respect to the total travel distance, the construction heuristic compares favorably versus a column generation method and a two-phase method. In addition, the construction heuristic is computationally faster than both previous methods. This construction heuristic could be useful in developing initial solutions, very quickly, for a heuristic, algorithm, or exact procedure.
基金supported by Doctoral Foundation of Ministry of Education of China (Grant No.20070006011)
文摘For the constant distance spacing policy,the existing researches of the string stability focus on the single-predecessor information framework（SPIF） and predecessor-successor information framework（PSIF）.The research results demonstrated that the string stability could not be guaranteed with the SPIF,and then the PSIF was proposed to resolve this string instability.But the issue,whether the string stability can be guaranteed when applying the PSIF,is still controversial.Meanwhile,most of the previous researches on the string stability were conducted without consideration of the parasitic time delays and lags.In this paper,the practical longitudinal vehicle dynamics model is built with consideration of the parasitic time delays and lags existing in the actuators,sensors or the communication systems.Secondly,the detailed theoretical analysis of string stability in frequency domain is conducted to demonstrate that the classical linear control laws can not ensure the string stability when applying both the symmetrical PSIF（SPSIF） and asymmetrical PSIF（APSIF）.Thirdly,a control law,which adds the position and velocity information of the leading vehicle,is proposed to guarantee string stability for small/medium platoon,and the other control law,which adds the acceleration information of the controlled vehicle,is proposed to guarantee string stability for large platoon as well as small/medium platoon.Finally,the comparative simulation is conducted to confirm the conducted analysis and the proposed control laws.The conducted research completes the means to analyze the string stability in frequency domain,provides the parameters＇ reference for the design and implementation of the practical automatic following controllers,and improves the reliability and stability of the platoon of automatic vehicles.
文摘All automobile manufacturing companies, Google and Microsoft have announced recently their production of the Fully Automated Autonomous Vehicles (FAAVs), otherwise known as driverless cars. A few FAAVs would be available in the market as early as in 2018, but mostly in 2020’s. When FAAVs will be available to and become affordable by the average consumers, the implications to the society would be far reaching. The purpose of the paper is to examine the prospect of the popularity of FAAVs and their socio-economic implications to the future society of the World. The paper examines potential impacts on selected sectors of the society including changes in demand for automobiles, its impact on the use of oil, on the environment, and on urban land uses, to list a few.
