The Experts below are selected from a list of 13440 Experts worldwide ranked by ideXlab platform
Kassas, Zaher M. - One of the best experts on this subject based on the ideXlab platform.
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Integrity-Based Path Planning Strategy for Urban Autonomous Vehicular Navigation Using GPS and Cellular Signals
eScholarship University of California, 2020Co-Authors: Lee Halim, Seo Jiwon, Kassas, Zaher M.Abstract:An integrity-based Path planning strategy for autonomous ground vehicle (AGV) navigation in urban environments is developed. The vehicle is assumed to navigate by utilizing cellular long-term evolution (LTE) signals in addition to Global Positioning System (GPS) signals. Given a desired destination, an optimal Path is calculated, which minimizes a cost function that considers both the horizontal protection level (HPL) and travel distance. The constraints are that (i) the ratio of nodes with faulty signals to the total nodes be lower than a maximum allowable ratio and (ii) the HPLs along each Candidate Path be lower than the horizontal alert limit (HAL). To predict the faults and HPL before the vehicle is driven, GPS and LTE pseudoranges along the Candidate Paths are generated utilizing a commercial ray-tracing software and three-dimensional (3D) terrain and building maps. Simulated pseudoranges inform the Path planning algorithm about potential biases due to reflections from buildings in urban environments. Simulation results are presented showing that the optimal Path produced by the proposed Path planning strategy has the minimum average HPL among the Candidate Paths
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Integrity-Based Path Planning Strategy for Urban Autonomous Vehicular Navigation Using GPS and Cellular Signals
'Institute of Navigation', 2020Co-Authors: Lee Halim, Seo Jiwon, Kassas, Zaher M.Abstract:An integrity-based Path planning strategy for autonomous ground vehicle (AGV) navigation in urban environments is developed. The vehicle is assumed to navigate by utilizing cellular long-term evolution (LTE) signals in addition to Global Positioning System (GPS) signals. Given a desired destination, an optimal Path is calculated, which minimizes a cost function that considers both the horizontal protection level (HPL) and travel distance. The constraints are that (i) the ratio of nodes with faulty signals to the total nodes be lower than a maximum allowable ratio and (ii) the HPLs along each Candidate Path be lower than the horizontal alert limit (HAL). To predict the faults and HPL before the vehicle is driven, GPS and LTE pseudoranges along the Candidate Paths are generated utilizing a commercial ray-tracing software and three-dimensional (3D) terrain and building maps. Simulated pseudoranges inform the Path planning algorithm about potential biases due to reflections from buildings in urban environments. Simulation results are presented showing that the optimal Path produced by the proposed Path planning strategy has the minimum average HPL among the Candidate Paths.Comment: Submitted to ION GNSS+ 202
Lee Halim - One of the best experts on this subject based on the ideXlab platform.
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Integrity-Based Path Planning Strategy for Urban Autonomous Vehicular Navigation Using GPS and Cellular Signals
eScholarship University of California, 2020Co-Authors: Lee Halim, Seo Jiwon, Kassas, Zaher M.Abstract:An integrity-based Path planning strategy for autonomous ground vehicle (AGV) navigation in urban environments is developed. The vehicle is assumed to navigate by utilizing cellular long-term evolution (LTE) signals in addition to Global Positioning System (GPS) signals. Given a desired destination, an optimal Path is calculated, which minimizes a cost function that considers both the horizontal protection level (HPL) and travel distance. The constraints are that (i) the ratio of nodes with faulty signals to the total nodes be lower than a maximum allowable ratio and (ii) the HPLs along each Candidate Path be lower than the horizontal alert limit (HAL). To predict the faults and HPL before the vehicle is driven, GPS and LTE pseudoranges along the Candidate Paths are generated utilizing a commercial ray-tracing software and three-dimensional (3D) terrain and building maps. Simulated pseudoranges inform the Path planning algorithm about potential biases due to reflections from buildings in urban environments. Simulation results are presented showing that the optimal Path produced by the proposed Path planning strategy has the minimum average HPL among the Candidate Paths
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Integrity-Based Path Planning Strategy for Urban Autonomous Vehicular Navigation Using GPS and Cellular Signals
'Institute of Navigation', 2020Co-Authors: Lee Halim, Seo Jiwon, Kassas, Zaher M.Abstract:An integrity-based Path planning strategy for autonomous ground vehicle (AGV) navigation in urban environments is developed. The vehicle is assumed to navigate by utilizing cellular long-term evolution (LTE) signals in addition to Global Positioning System (GPS) signals. Given a desired destination, an optimal Path is calculated, which minimizes a cost function that considers both the horizontal protection level (HPL) and travel distance. The constraints are that (i) the ratio of nodes with faulty signals to the total nodes be lower than a maximum allowable ratio and (ii) the HPLs along each Candidate Path be lower than the horizontal alert limit (HAL). To predict the faults and HPL before the vehicle is driven, GPS and LTE pseudoranges along the Candidate Paths are generated utilizing a commercial ray-tracing software and three-dimensional (3D) terrain and building maps. Simulated pseudoranges inform the Path planning algorithm about potential biases due to reflections from buildings in urban environments. Simulation results are presented showing that the optimal Path produced by the proposed Path planning strategy has the minimum average HPL among the Candidate Paths.Comment: Submitted to ION GNSS+ 202
Akihiro Otaka - One of the best experts on this subject based on the ideXlab platform.
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low latency routing scheme for a fronthaul bridged network
IEEE\ OSA Journal of Optical Communications and Networking, 2018Co-Authors: Yu Nakayama, Takahiro Kubo, Daisuke Hisano, Youichi Fukada, Jun Terada, Akihiro OtakaAbstract:A fronthaul bridged network has attracted attention as a means of efficiently constructing the centralized radio access network (C-RAN) architecture. If we change the functional split of C-RAN and employ timedivision duplex (TDD), the data rate in fronthaul will become variable, and the global synchronization of front-haul streams will occur. This feature results in an increase in the queuing delay in fronthaul bridges among fronthaul flows. To address this problem, this paper proposes a novel low-latency routing scheme designed to minimize the worst-case delay in fronthaul networks with Path-control protocols. The proposed scheme formulates the worst-case delay of each fronthaul stream based on the distribution of nodes, the propagation delay, and metric of the links. It selects the set of Paths that minimizes the maximum value of the worst-case delay from the Candidate Path sets for fronthaul flows generated with the k-th shortest Path algorithm. We confirmed with computer simulations that the proposed scheme can adequately minimize the worst-case delay, irrespective of the network topology. The maximum queuing delay is minimized by considering the time synchronization between fronthaul flows and the burst size determined by the TDD subframe length.
Seo Jiwon - One of the best experts on this subject based on the ideXlab platform.
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Integrity-Based Path Planning Strategy for Urban Autonomous Vehicular Navigation Using GPS and Cellular Signals
eScholarship University of California, 2020Co-Authors: Lee Halim, Seo Jiwon, Kassas, Zaher M.Abstract:An integrity-based Path planning strategy for autonomous ground vehicle (AGV) navigation in urban environments is developed. The vehicle is assumed to navigate by utilizing cellular long-term evolution (LTE) signals in addition to Global Positioning System (GPS) signals. Given a desired destination, an optimal Path is calculated, which minimizes a cost function that considers both the horizontal protection level (HPL) and travel distance. The constraints are that (i) the ratio of nodes with faulty signals to the total nodes be lower than a maximum allowable ratio and (ii) the HPLs along each Candidate Path be lower than the horizontal alert limit (HAL). To predict the faults and HPL before the vehicle is driven, GPS and LTE pseudoranges along the Candidate Paths are generated utilizing a commercial ray-tracing software and three-dimensional (3D) terrain and building maps. Simulated pseudoranges inform the Path planning algorithm about potential biases due to reflections from buildings in urban environments. Simulation results are presented showing that the optimal Path produced by the proposed Path planning strategy has the minimum average HPL among the Candidate Paths
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Integrity-Based Path Planning Strategy for Urban Autonomous Vehicular Navigation Using GPS and Cellular Signals
'Institute of Navigation', 2020Co-Authors: Lee Halim, Seo Jiwon, Kassas, Zaher M.Abstract:An integrity-based Path planning strategy for autonomous ground vehicle (AGV) navigation in urban environments is developed. The vehicle is assumed to navigate by utilizing cellular long-term evolution (LTE) signals in addition to Global Positioning System (GPS) signals. Given a desired destination, an optimal Path is calculated, which minimizes a cost function that considers both the horizontal protection level (HPL) and travel distance. The constraints are that (i) the ratio of nodes with faulty signals to the total nodes be lower than a maximum allowable ratio and (ii) the HPLs along each Candidate Path be lower than the horizontal alert limit (HAL). To predict the faults and HPL before the vehicle is driven, GPS and LTE pseudoranges along the Candidate Paths are generated utilizing a commercial ray-tracing software and three-dimensional (3D) terrain and building maps. Simulated pseudoranges inform the Path planning algorithm about potential biases due to reflections from buildings in urban environments. Simulation results are presented showing that the optimal Path produced by the proposed Path planning strategy has the minimum average HPL among the Candidate Paths.Comment: Submitted to ION GNSS+ 202
And Yoshida K. - One of the best experts on this subject based on the ideXlab platform.
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Dynamic Simulation-Based Action Planner for a Reconfigurable Hybrid Leg Wheel Planetary Exploration Rover
2010Co-Authors: Rohmer E., Reina G., And Yoshida K.Abstract:In this paper, an action planning algorithm is presented for a reconfigurable hybrid leg–wheel mobile robot. Hybrid leg–wheel robots have recently receiving growing interest from the space community to explore planets, as they offer a solution to improve speed and mobility on uneven terrain. One critical issue connected with them is the study of an appropriate strategy to define when to use one over the other locomotion mode, depending on the soil properties and topology. Although this step is crucial to reach the full hybrid mechanism’s potential, little attention has been devoted to this topic. Given an elevation map of the environment, we developed an action planner that selects the appropriate locomotion mode along an optimal Path toward a point of scientific interest. This tool is helpful for the space mission team to decide the next move of the robot during the exploration. First, a Candidate Path is generated based on topology and specifications’ criteria functions. Then, switching actions are defined along this Path based on the robot’s performance in each motion mode. Finally, the Path is rated based on the energy profile evaluated using a dynamic simulator. The proposed approach is applied to a concept prototype of a reconfigurable hybrid wheel–leg robot for planetary exploration through extensive simulations and real experiments
