Autonomous-rail rapid transit(ART)is a new medium-capacity rapid transportation system with punctuality,comfort and convenience,but low-cost construction.Combined velocity planning is a critical approach to meet the r...Autonomous-rail rapid transit(ART)is a new medium-capacity rapid transportation system with punctuality,comfort and convenience,but low-cost construction.Combined velocity planning is a critical approach to meet the requirements of energy-saving and punctuality.An ART velocity pre-planning and re-planning strategy based on the combination of punctuality dynamic programming(PDP)and pseudospectral(PS)method is proposed in this paper.Firstly,the longitudinal dynamics model of ART is established by a multi-particle model.Secondly,the PDP algorithm with global optimal characteristics is adopted as the pre-planning strategy.A model for determining the number of collocation points of the real-time PS method is proposed to improve the energy-saving effect while ensuring computation efficiency.Then the enhanced PS method is utilized to design the velocity re-planning strategy.Finally,simulations are conducted in the typical scenario with sloping roads,traffic lights,and intrusion of the pedestrian.The simulation results indicate that the ART with the proposed velocity trajectory optimization strategy can meet the punctuality requirement,and obtain better economy efficiency compared with the punctuality green light optimal speed advisory(PGLOSA).展开更多
Energy management is an important issue in the operation of hybrid electric trains.To achieve optimal energy utilization,this paper proposes a dynamic programming approach considering state space reduction to solve th...Energy management is an important issue in the operation of hybrid electric trains.To achieve optimal energy utilization,this paper proposes a dynamic programming approach considering state space reduction to solve the optimization problem.Dynamic programming,as an exact algorithm,has a clear advantage in terms of solution accuracy,but its efficiency is low when dealing with large-scale optimization problems.Firstly,the paper introduces the topology and operation modes of hydrogen fuel cell hybrid trains,as well as the basic principles and computational steps of dynamic programming.Secondly,several state reduction strategies are designed to improve solution efficiency,and an objective function considering both passenger experience and operational costs is proposed.The numerical experimental results demonstrate that the proposed method not only solves the inherent problems of dynamic programming but also outperforms traditional dynamic programming and level set-based optimization methods in terms of computational accuracy and time.Furthermore,experimental results based on real driving conditions validate the applicability of the proposed method.展开更多
Autonomous-rail Rapid Transit(ART)tram is a new type of multiple-articulated rubber-tire transit that utilizes intelligent perception,path tracking,and trajectory following control technologies to eliminate reliance o...Autonomous-rail Rapid Transit(ART)tram is a new type of multiple-articulated rubber-tire transit that utilizes intelligent perception,path tracking,and trajectory following control technologies to eliminate reliance on physical railway tracks.The adoption of power batteries,hydrogen energy,wheel-edge motor drive,and other technologies has comprehensively realized the dual advantages of large-capacity rail transportation,which is punctual,high volume,energy-saving,and environmentally friendly,as well as the flexibility and low comprehensive cost of traditional bus operations.This has created a brand-new urban rail transit model.This article first introduces the ART tram systems architecture,operating principles,applicable scenarios.Secondly,it introduces the core subsystems of ART tram vehicle structure,electrical system,and energy storage system.Thirdly,it focuses on analyzing the structure composition and control principles of the Automatic All-Wheel Steering System,which includes two key core subsystems:path tracking control subsystems and trajectory following control subsystems.Then,a horizontal comparison is made between the performance advantages and disadvantages of ART and other transportation systems,and the application status of ART tram is summarized.Finally,some common issues related to the development of ART tram are discussed,and a development plan for future ART systems is proposed to better integrate ART tram into urban transportation and meet people's demands for intelligent,comfortable,fast,and environmentally friendly urban public transportation.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52072073 and 52025121)National Key R&D Program of China(Grant No.2018YFB1201602).
文摘Autonomous-rail rapid transit(ART)is a new medium-capacity rapid transportation system with punctuality,comfort and convenience,but low-cost construction.Combined velocity planning is a critical approach to meet the requirements of energy-saving and punctuality.An ART velocity pre-planning and re-planning strategy based on the combination of punctuality dynamic programming(PDP)and pseudospectral(PS)method is proposed in this paper.Firstly,the longitudinal dynamics model of ART is established by a multi-particle model.Secondly,the PDP algorithm with global optimal characteristics is adopted as the pre-planning strategy.A model for determining the number of collocation points of the real-time PS method is proposed to improve the energy-saving effect while ensuring computation efficiency.Then the enhanced PS method is utilized to design the velocity re-planning strategy.Finally,simulations are conducted in the typical scenario with sloping roads,traffic lights,and intrusion of the pedestrian.The simulation results indicate that the ART with the proposed velocity trajectory optimization strategy can meet the punctuality requirement,and obtain better economy efficiency compared with the punctuality green light optimal speed advisory(PGLOSA).
文摘Energy management is an important issue in the operation of hybrid electric trains.To achieve optimal energy utilization,this paper proposes a dynamic programming approach considering state space reduction to solve the optimization problem.Dynamic programming,as an exact algorithm,has a clear advantage in terms of solution accuracy,but its efficiency is low when dealing with large-scale optimization problems.Firstly,the paper introduces the topology and operation modes of hydrogen fuel cell hybrid trains,as well as the basic principles and computational steps of dynamic programming.Secondly,several state reduction strategies are designed to improve solution efficiency,and an objective function considering both passenger experience and operational costs is proposed.The numerical experimental results demonstrate that the proposed method not only solves the inherent problems of dynamic programming but also outperforms traditional dynamic programming and level set-based optimization methods in terms of computational accuracy and time.Furthermore,experimental results based on real driving conditions validate the applicability of the proposed method.
文摘Autonomous-rail Rapid Transit(ART)tram is a new type of multiple-articulated rubber-tire transit that utilizes intelligent perception,path tracking,and trajectory following control technologies to eliminate reliance on physical railway tracks.The adoption of power batteries,hydrogen energy,wheel-edge motor drive,and other technologies has comprehensively realized the dual advantages of large-capacity rail transportation,which is punctual,high volume,energy-saving,and environmentally friendly,as well as the flexibility and low comprehensive cost of traditional bus operations.This has created a brand-new urban rail transit model.This article first introduces the ART tram systems architecture,operating principles,applicable scenarios.Secondly,it introduces the core subsystems of ART tram vehicle structure,electrical system,and energy storage system.Thirdly,it focuses on analyzing the structure composition and control principles of the Automatic All-Wheel Steering System,which includes two key core subsystems:path tracking control subsystems and trajectory following control subsystems.Then,a horizontal comparison is made between the performance advantages and disadvantages of ART and other transportation systems,and the application status of ART tram is summarized.Finally,some common issues related to the development of ART tram are discussed,and a development plan for future ART systems is proposed to better integrate ART tram into urban transportation and meet people's demands for intelligent,comfortable,fast,and environmentally friendly urban public transportation.
