The Experts below are selected from a list of 110754 Experts worldwide ranked by ideXlab platform
Shu Lin - One of the best experts on this subject based on the ideXlab platform.
-
On a spatiotemporally discrete Urban Traffic model
IET Intelligent Transport Systems, 2014Co-Authors: Shu Lin, Bart De Schutter, Andreas Hegyi, Hans HellendoornAbstract:In order to control Urban Traffic with model-based control methods, a proper Traffic model is very important. This Traffic control model needs to have enough descriptive power to reproduce relevant Traffic phenomena, and it also has to be fast enough to be used in practice. Consequently, macroscopic Urban Traffic flow models are usually applied as control models. In this study, a macroscopic spatiotemporally discrete Urban Traffic model with a variable sampling time interval is proposed for model-based control strategies. By selecting proper sampling time intervals and sampling space distances, it allows us to balance modelling accuracy and computational complexity of the spatiotemporally discrete model. In addition, an Urban Traffic Courant-Friedrichs-Lewy (CFL) condition is deduced for spatiotemporally discrete Urban Traffic models, which is a sufficient condition to guarantee the discrete model to bear enough descriptive modelling power to reproduce necessary Traffic phenomena. The model is analysed and evaluated based on the model requirements for control purposes. The simulation results are compared for the situations where the CFL condition is violated and not violated.
-
a fast network partition method for large scale Urban Traffic networks
Journal of Control Theory and Applications, 2013Co-Authors: Zhao Zhou, Shu LinAbstract:In order to control the large-scale Urban Traffic network through hierarchical or decentralized methods, it is necessary to exploit a network partition method, which should be both effective in extracting subnetworks and fast to compute. In this paper, a new approach to calculate the correlation degree, which determines the desire for interconnection between two adjacent intersections, is first proposed. It is used as a weight of a link in an Urban Traffic network, which considers both the physical characteristics and the dynamic Traffic information of the link. Then, a fast network division approach by optimizing the modularity, which is a criterion to distinguish the quality of the partition results, is applied to identify the subnetworks for large-scale Urban Traffic networks. Finally, an application to a specified Urban Traffic network is investigated using the proposed algorithm. The results show that it is an effective and efficient method for partitioning Urban Traffic networks automatically in real world.
-
a dynamic network partition method for heterogenous Urban Traffic networks
International Conference on Intelligent Transportation Systems, 2012Co-Authors: Zhao Zhou, Shu LinAbstract:Recently, it has been shown that Macroscopic Fundamental Diagrams(MFDs) existing in large scale Urban Traffic networks paly an important role in dynamic Traffic management, Traffic signal control and mitigation of Urban Traffic congestion. A well defined MFD can be derived from a homogeneous Urban Traffic network with similar Traffic conditions. In reality, however, most large scale Traffic networks are usually heterogeneous networks with various road types and uneven distribution of congestion. In order to use the MFD concept for controlling the large scale Urban Traffic network through hierarchical or decentralized methods, it is necessary to exploit a network partition method, which should be both effective in extracting homogeneous sub-networks and fast to compute. In this paper, a new approach to calculate the correlation degree, which describes the Traffic conditions between two adjacent intersections quantitatively, is first proposed. Then, a fast network division approach by optimizing the modularity, which is a criterion to distinguish the quality of the partition results, is applied to identify the homogeneous sub-networks for large scale Urban Traffic networks. Finally, an application to a specified Urban Traffic network is investigated by using the proposed algorithm. The results show that it is an effective and efficient method for partitioning heterogeneous Urban Traffic networks automatically.
-
On a spatiotemporally discrete Urban Traffic model
IFAC Proceedings Volumes, 2011Co-Authors: Shu Lin, Bart De Schutter, Andreas Hegyi, J. HellendoornAbstract:Abstract In order to control Urban Traffic with model-based control methods, a proper Traffic model is very important. This Traffic control model needs to have enough descriptive power to reproduce relevant Traffic phenomena, and it also has to be fast enough to be used in practice. Therefore, macroscopic Urban Traffic flow models are usually applied as control models. These models are normally sampled temporally and spatially into discrete models so as to be simulated using digital computers. In this paper, a spatiotemporally discrete Urban Traffic model with a variable sampling time interval is proposed for model-based predictive control, which allows to balance modeling accuracy and computational complexity. The model is analyzed and evaluated based on the model requirements for control purposes. In addition, conditions are given to selecting suitable sampling time intervals for the models that are used to control Urban Traffic networks.
-
An Efficient Model for Urban Traffic Network Control
IFAC Proceedings Volumes, 2008Co-Authors: Shu LinAbstract:Abstract In order to control the Urban Traffic network through optimization methods, it is necessary to establish a proper Urban Traffic network model. This model should be both accurate in describing the network Traffic and simple to compute. In this paper, an existing link model is at first improved to describe the main Traffic dynamic behaviors more accurately. Then, a general Urban Traffic network topology is proposed. By modeling the network elements, a macroscopic model for Urban Traffic networks can be established. The model is compared with the microscopic Traffic model CORSIM. It shows that this model well balances the accuracy and simpleness, and is thus suitable to real-time control.
Wang Yan-xin - One of the best experts on this subject based on the ideXlab platform.
-
Information Analysis and Organization for Coordination of Urban Traffic Control System with Urban Traffic Flow Guidance System
Journal of Highway and Transportation Research and Development, 2007Co-Authors: Chen Xin, Yang Zhao-sheng, Wang Hai-yang, Wang Yan-xinAbstract:Information analysis and information organization for coordination of Urban Traffic control system with the Urban Traffic flow guidance system are re,arched in the paper. The information requirements and the data characteristics of the Urban Traffic control system and the Urban Traffic flow guidance system are analyzed. Traffic data structure is described by the data characteristics. Information organization flow chart for the coordination is put forward based on the information data characteristics and relationship of the two systems. Multi-sourees Traffic information processing is highlighted, which is the key technology of information organization. The study provides method guide for real application system development for the coordination of Urban Traffic control system with the Urban Traffic flow guidance system.
Jianping Sun - One of the best experts on this subject based on the ideXlab platform.
-
Study on information processing in the integration of Urban Traffic flow guidance system and Urban Traffic control system
Proceedings of the 2003 IEEE International Conference on Intelligent Transportation Systems, 1Co-Authors: Zhaosheng Yang, Chunxiao Yang, Jianping SunAbstract:This paper describes a theoretical model of information processing in the integration of Urban Traffic flow guidance systems (UTFGS) and Urban Traffic control systems (UTCS), and suggests the application of travelers' behavior-based dynamic Traffic assignment (DTA) to the process. In addition, the article also applies computer supported cooperative work (CSCW) into the network communication in the integration of UTFGS and UTCS. At the same time, we present a means of data communication in the integration of control and guidance based on multicast communication.
Hans Hellendoorn - One of the best experts on this subject based on the ideXlab platform.
-
On a spatiotemporally discrete Urban Traffic model
IET Intelligent Transport Systems, 2014Co-Authors: Shu Lin, Bart De Schutter, Andreas Hegyi, Hans HellendoornAbstract:In order to control Urban Traffic with model-based control methods, a proper Traffic model is very important. This Traffic control model needs to have enough descriptive power to reproduce relevant Traffic phenomena, and it also has to be fast enough to be used in practice. Consequently, macroscopic Urban Traffic flow models are usually applied as control models. In this study, a macroscopic spatiotemporally discrete Urban Traffic model with a variable sampling time interval is proposed for model-based control strategies. By selecting proper sampling time intervals and sampling space distances, it allows us to balance modelling accuracy and computational complexity of the spatiotemporally discrete model. In addition, an Urban Traffic Courant-Friedrichs-Lewy (CFL) condition is deduced for spatiotemporally discrete Urban Traffic models, which is a sufficient condition to guarantee the discrete model to bear enough descriptive modelling power to reproduce necessary Traffic phenomena. The model is analysed and evaluated based on the model requirements for control purposes. The simulation results are compared for the situations where the CFL condition is violated and not violated.
Chen Xin - One of the best experts on this subject based on the ideXlab platform.
-
Information Analysis and Organization for Coordination of Urban Traffic Control System with Urban Traffic Flow Guidance System
Journal of Highway and Transportation Research and Development, 2007Co-Authors: Chen Xin, Yang Zhao-sheng, Wang Hai-yang, Wang Yan-xinAbstract:Information analysis and information organization for coordination of Urban Traffic control system with the Urban Traffic flow guidance system are re,arched in the paper. The information requirements and the data characteristics of the Urban Traffic control system and the Urban Traffic flow guidance system are analyzed. Traffic data structure is described by the data characteristics. Information organization flow chart for the coordination is put forward based on the information data characteristics and relationship of the two systems. Multi-sourees Traffic information processing is highlighted, which is the key technology of information organization. The study provides method guide for real application system development for the coordination of Urban Traffic control system with the Urban Traffic flow guidance system.
