A new real-time map matching algorithm based on fuzzy logic is proposed. 3 main factors affecting the reliability of map matching, including the distance between the vehicle location and the matching road segment, the...A new real-time map matching algorithm based on fuzzy logic is proposed. 3 main factors affecting the reliability of map matching, including the distance between the vehicle location and the matching road segment, the angle between the vehicle direction and the road segment direction and the road connectivity are discussed. Fuzzy rules for the distance, angle and connectivity are presented to calculate the matching reliability. 2 indicators for estimating the matching reliability are then derived, one is the lower limit of the reliability, and the other is the limit error of the difference between the maximal value and the second-maximal value of the reliability. A real-time map-matching system based on fuzzy logic is therefore developed. Using the real data of global positioning system(GIS) based navigation and geographic information system(GPS) based road map, the method is verified and the (results) prove the effectiveness of the proposed method.展开更多
A scheme for an automatic road surface modeling from a noisy point cloud is presented. The normal vectors of the point cloud are estimated by distance-weighted fitting of local plane. Then, an automatic recognition of...A scheme for an automatic road surface modeling from a noisy point cloud is presented. The normal vectors of the point cloud are estimated by distance-weighted fitting of local plane. Then, an automatic recognition of the road surface from noise is performed based on the fuzzy clustering of normal vectors, with which the mean value is calculated and the projecting plane of point cloud is created to obtain the geometric model accordingly. Based on fuzzy clustering of the intensity attributed to each point, different objects on the road surface are assigned different colors for representing abundant appearances. This unsupervised method is demonstrated in the experiment and shows great effectiveness in reconstructing and rendering better road surface.展开更多
The turning motion of a tracked pipeline-robot implemented by skid steering is a nonholonomic dynamic problem with intrinsic nonlinearity, to which the classical control method is inappropriate and cannot be applied. ...The turning motion of a tracked pipeline-robot implemented by skid steering is a nonholonomic dynamic problem with intrinsic nonlinearity, to which the classical control method is inappropriate and cannot be applied. This paper presents a novel path tracking control method based on hierarchical fuzzy structure. The controller consists of three sub-level low dimensional fuzzy control systems： fuzzy supervisory control, fuzzy steering and fuzzy velocity control. As a result, establishing the bases of rules for the fuzzy control becomes feasible and simplified, and the related controller can be adapted to complicated ground and environment. Using this method, the number of fuzzy controt rules is greatly decreased so that the curse of dimensionality causing the multivariable problem does not occur. Simulation and experimental results validate the effectiveness of the proposed method with satisfied performance on path tracking. Autonomous navigation of the caterpillar-inspired pipeline-robot is also implemented based on the sensor feedbacks.展开更多
Sustainability is popularly defined as meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Social, economic and environmental parameters are most...Sustainability is popularly defined as meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Social, economic and environmental parameters are most commonly accepted as the three pillars of sustainability. In this paper, various sustainability indicators have been identified during the construction stage for elevated transportation corridors and thereafter classified under various categories. Using fuzzy VIKOR technique, sustainability evaluation of transportation corridors is made on two selected project sites of two different government organizations using various identified sustainability indicators, i.e., a 3.2-km long elevated road project under construction from Vikaspuri to Meerabagh in West Delhi by PWD （Public Works Department） and the metro rail elevated corridor （part） from Punjabi Bagh to Mayapuri as a part of Phase 3, Line 7 by DMRC （Delhi Metro Rail Corporation）. The study is made at both sites in the midst of the construction period and it is identified that during the construction stage, the sustainability of these transportation corridors is just not limited to three pillars, but in actuality, it is much beyond that. From the study, it is inferred that the metro rail elevated corridor is a more sustainable corridor, in the context of the identified sustainability indicators.展开更多
Some microscopic traffic simulations on urban road network are developed up to now. However, the effect of urban transport policy in the local city is influenced with the complex interaction of automobile traffic and ...Some microscopic traffic simulations on urban road network are developed up to now. However, the effect of urban transport policy in the local city is influenced with the complex interaction of automobile traffic and public transport traffic. Particularly, behaviours of vehicles should be described with the fuzziness of the subjective recognition and operation. On the other hand, the trip makers are influenced by various transport policies in terms of mode choice behaviour. The change in mode choice behaviour and number of public transport mode users would eventually affect traffic flow conditions on road network. Modal spilt and traffic conditions of a network are interrelated. Therefore, the present study mainly aims to integrate mode choice model and microscopic traffic simulation model based on fuzzy logic. In the study, the fuzzy logic based mode choice model is proposed. The proposed mode choice model and the existing microscopic traffic simulation model are combined. The developed model has been applied on real urban network to demonstrate the effectiveness of the installation of LRT system. Finally, it is helpful for evaluation of transport policy that the fuzzy logic based microscopic traffic simulation with modal choice model has been constructed.展开更多
As the idea of the sustainable development wins support among the people, people have already realized that not only should the road have the transportation function, but we also should consider the rationality of the...As the idea of the sustainable development wins support among the people, people have already realized that not only should the road have the transportation function, but we also should consider the rationality of the road construction fi＇om the multiple angles of the landscape ecology, and the visual art and so on. From the point of view of the landscape ecology, combined with the characteristics of the landscape ecology and the overall targets and requirements of the evaluation, this article constructs a three-tier system of indicators, uses the fuzzy comprehensive evaluation model based on the analytic hierarchy process to evaluate the road landscape, and makes an empirical analysis with the evaluation of the road landscape fi＇om the Luoshi Road to the East Lake Road in the Second Loop of Wuhan City as an example.展开更多
基金Projects(40301043 and 40171078) supported by the National Natural Science Foundation of China
文摘A new real-time map matching algorithm based on fuzzy logic is proposed. 3 main factors affecting the reliability of map matching, including the distance between the vehicle location and the matching road segment, the angle between the vehicle direction and the road segment direction and the road connectivity are discussed. Fuzzy rules for the distance, angle and connectivity are presented to calculate the matching reliability. 2 indicators for estimating the matching reliability are then derived, one is the lower limit of the reliability, and the other is the limit error of the difference between the maximal value and the second-maximal value of the reliability. A real-time map-matching system based on fuzzy logic is therefore developed. Using the real data of global positioning system(GIS) based navigation and geographic information system(GPS) based road map, the method is verified and the (results) prove the effectiveness of the proposed method.
基金Supported by the National Natural Science Foundation of China （No.40471089） and the Key Laboratory of Geo-informatics of State Bureau of Surveying and Mapping.
文摘A scheme for an automatic road surface modeling from a noisy point cloud is presented. The normal vectors of the point cloud are estimated by distance-weighted fitting of local plane. Then, an automatic recognition of the road surface from noise is performed based on the fuzzy clustering of normal vectors, with which the mean value is calculated and the projecting plane of point cloud is created to obtain the geometric model accordingly. Based on fuzzy clustering of the intensity attributed to each point, different objects on the road surface are assigned different colors for representing abundant appearances. This unsupervised method is demonstrated in the experiment and shows great effectiveness in reconstructing and rendering better road surface.
基金Supported by the National Science Foundation of China （ No. 60935001 ） and New Century Excellent Talents in University of Chinese Ministry of Education （NCET-06-0398）.
文摘The turning motion of a tracked pipeline-robot implemented by skid steering is a nonholonomic dynamic problem with intrinsic nonlinearity, to which the classical control method is inappropriate and cannot be applied. This paper presents a novel path tracking control method based on hierarchical fuzzy structure. The controller consists of three sub-level low dimensional fuzzy control systems： fuzzy supervisory control, fuzzy steering and fuzzy velocity control. As a result, establishing the bases of rules for the fuzzy control becomes feasible and simplified, and the related controller can be adapted to complicated ground and environment. Using this method, the number of fuzzy controt rules is greatly decreased so that the curse of dimensionality causing the multivariable problem does not occur. Simulation and experimental results validate the effectiveness of the proposed method with satisfied performance on path tracking. Autonomous navigation of the caterpillar-inspired pipeline-robot is also implemented based on the sensor feedbacks.
文摘Sustainability is popularly defined as meeting the needs of the present generation without compromising the ability of future generations to meet their own needs. Social, economic and environmental parameters are most commonly accepted as the three pillars of sustainability. In this paper, various sustainability indicators have been identified during the construction stage for elevated transportation corridors and thereafter classified under various categories. Using fuzzy VIKOR technique, sustainability evaluation of transportation corridors is made on two selected project sites of two different government organizations using various identified sustainability indicators, i.e., a 3.2-km long elevated road project under construction from Vikaspuri to Meerabagh in West Delhi by PWD （Public Works Department） and the metro rail elevated corridor （part） from Punjabi Bagh to Mayapuri as a part of Phase 3, Line 7 by DMRC （Delhi Metro Rail Corporation）. The study is made at both sites in the midst of the construction period and it is identified that during the construction stage, the sustainability of these transportation corridors is just not limited to three pillars, but in actuality, it is much beyond that. From the study, it is inferred that the metro rail elevated corridor is a more sustainable corridor, in the context of the identified sustainability indicators.
文摘Some microscopic traffic simulations on urban road network are developed up to now. However, the effect of urban transport policy in the local city is influenced with the complex interaction of automobile traffic and public transport traffic. Particularly, behaviours of vehicles should be described with the fuzziness of the subjective recognition and operation. On the other hand, the trip makers are influenced by various transport policies in terms of mode choice behaviour. The change in mode choice behaviour and number of public transport mode users would eventually affect traffic flow conditions on road network. Modal spilt and traffic conditions of a network are interrelated. Therefore, the present study mainly aims to integrate mode choice model and microscopic traffic simulation model based on fuzzy logic. In the study, the fuzzy logic based mode choice model is proposed. The proposed mode choice model and the existing microscopic traffic simulation model are combined. The developed model has been applied on real urban network to demonstrate the effectiveness of the installation of LRT system. Finally, it is helpful for evaluation of transport policy that the fuzzy logic based microscopic traffic simulation with modal choice model has been constructed.
文摘As the idea of the sustainable development wins support among the people, people have already realized that not only should the road have the transportation function, but we also should consider the rationality of the road construction fi＇om the multiple angles of the landscape ecology, and the visual art and so on. From the point of view of the landscape ecology, combined with the characteristics of the landscape ecology and the overall targets and requirements of the evaluation, this article constructs a three-tier system of indicators, uses the fuzzy comprehensive evaluation model based on the analytic hierarchy process to evaluate the road landscape, and makes an empirical analysis with the evaluation of the road landscape fi＇om the Luoshi Road to the East Lake Road in the Second Loop of Wuhan City as an example.
