The Experts below are selected from a list of 303 Experts worldwide ranked by ideXlab platform

A. Ollero - One of the best experts on this subject based on the ideXlab platform.

  • Qualitative analysis of guidance and control methods for wind gradients exploitation with small fixed wing UAS
    2017 Workshop on Research Education and Development of Unmanned Aerial Systems (RED-UAS), 2017
    Co-Authors: Leopoldo Rodríguez, José A. Cobano, A. Ollero
    Abstract:

    In this paper, different Guidance and Control (GC) methods for trajectory tracking are analyzed. This effort considers the ongoing research effort regarding wind features characterization and trajectory generation. The investigation of GC methods is contextualized for long Duration missions of small Unmanned Aerial Systems (UAS). These are often hampered by the platform characteristics with cost and weight stringent restrictions. Therefore, innovative ways of increasing Flight Duration are necessary to fulfill the safety and reliability requirements for such missions fulfilling the cost and weight constraints. Atmospheric Energy Harvesting has been studied as an alternative for Flight Duration enhancement. The guidance and control strategies have been focused in the dynamic soaring case, in which the trajectories require precise tracking for energy gain. This gain depends on the tracking ability of the autopilot which motivates this analysis. As a conclusion to this analysis, two methodologies are chosen as candidates for GC, one based on pure differential geometry techniques to formulate simple error equations, and the other that uses adaptive control strategies based on vector field theory to formulate error equations and a Lyapunov function ensuring asymptotic stability with complex curve shapes and wind disturbances.

  • IROS - Thermal detection and generation of collision-free trajectories for cooperative soaring UAVs
    2013 IEEE RSJ International Conference on Intelligent Robots and Systems, 2013
    Co-Authors: J. A. Cobano, D. Alejo, S. Sukkarieh, G. Heredia, A. Ollero
    Abstract:

    This paper presents a cooperative system architecture that extends the Flight Duration of multiple gliding fixed-wing Unmanned Aerial Vehicles (UAVs) for long endurance missions. The missions are defined by a set of Points of Interest (PoI) and UAVs should pass through them. A module to detect and identify thermals is implemented to exploit their energy and extend the Flight Duration, known as static soaring. A collision-free trajectory planner based on the RRT* (Optimal Rapidly-exploring Random Trees) planning algorithm is implemented. The proposed system allows applications in real time because of its low computational needs. Simulations and experiments carried out in the airfield of La Cartuja (Seville, Spain) show the performance and advantages of the proposed system.

  • Multiple gliding UAV coordination for static soaring in real time applications
    2013 IEEE International Conference on Robotics and Automation, 2013
    Co-Authors: J. A. Cobano, D. Alejo, G. Heredia, S. Vera, A. Ollero
    Abstract:

    This paper addresses the problem of extending the Flight Duration of cooperative missions with multiple gliding fixed-wing UAVs by using the energy that comes from static soaring. We consider exploration missions where UAVs should pass through a set of Point of Interest (PoI) with the presence of thermals in the space. These thermals can be exploited to provide energy in terms of altitude for each gliding UAV. The objective of the mission is to extend the Flight Duration of each UAV to explore the environment without landing and decreasing the time to perform the mission. An algorithm named Bounded Recursive Heuristic Search (BRHS), based on Depth-First search techniques, is applied to the PoIs and to the UAVs. The main advantage is the real time application because of the low computational load. The paper presents a set of simulations and experiments have carried out in the airfield of La Cartuja (Seville, Spain).

  • ICRA - Multiple gliding UAV coordination for static soaring in real time applications
    2013 IEEE International Conference on Robotics and Automation, 2013
    Co-Authors: J. A. Cobano, D. Alejo, G. Heredia, S. Vera, A. Ollero
    Abstract:

    This paper addresses the problem of extending the Flight Duration of cooperative missions with multiple gliding fixed-wing UAVs by using the energy that comes from static soaring. We consider exploration missions where UAVs should pass through a set of Point of Interest (PoI) with the presence of thermals in the space. These thermals can be exploited to provide energy in terms of altitude for each gliding UAV. The objective of the mission is to extend the Flight Duration of each UAV to explore the environment without landing and decreasing the time to perform the mission. An algorithm named Bounded Recursive Heuristic Search (BRHS), based on Depth-First search techniques, is applied to the PoIs and to the UAVs. The main advantage is the real time application because of the low computational load. The paper presents a set of simulations and experiments have carried out in the airfield of La Cartuja (Seville, Spain).

  • Thermal detection and generation of collision-free trajectories for cooperative soaring UAVs
    2013 IEEE RSJ International Conference on Intelligent Robots and Systems, 2013
    Co-Authors: J. A. Cobano, D. Alejo, S. Sukkarieh, G. Heredia, A. Ollero
    Abstract:

    This paper presents a cooperative system architecture that extends the Flight Duration of multiple gliding fixed-wing Unmanned Aerial Vehicles (UAVs) for long endurance missions. The missions are defined by a set of Points of Interest (PoI) and UAVs should pass through them. A module to detect and identify thermals is implemented to exploit their energy and extend the Flight Duration, known as static soaring. A collision-free trajectory planner based on the RRT* (Optimal Rapidly-exploring Random Trees) planning algorithm is implemented. The proposed system allows applications in real time because of its low computational needs. Simulations and experiments carried out in the airfield of La Cartuja (Seville, Spain) show the performance and advantages of the proposed system.

J. A. Cobano - One of the best experts on this subject based on the ideXlab platform.

  • IROS - Thermal detection and generation of collision-free trajectories for cooperative soaring UAVs
    2013 IEEE RSJ International Conference on Intelligent Robots and Systems, 2013
    Co-Authors: J. A. Cobano, D. Alejo, S. Sukkarieh, G. Heredia, A. Ollero
    Abstract:

    This paper presents a cooperative system architecture that extends the Flight Duration of multiple gliding fixed-wing Unmanned Aerial Vehicles (UAVs) for long endurance missions. The missions are defined by a set of Points of Interest (PoI) and UAVs should pass through them. A module to detect and identify thermals is implemented to exploit their energy and extend the Flight Duration, known as static soaring. A collision-free trajectory planner based on the RRT* (Optimal Rapidly-exploring Random Trees) planning algorithm is implemented. The proposed system allows applications in real time because of its low computational needs. Simulations and experiments carried out in the airfield of La Cartuja (Seville, Spain) show the performance and advantages of the proposed system.

  • Multiple gliding UAV coordination for static soaring in real time applications
    2013 IEEE International Conference on Robotics and Automation, 2013
    Co-Authors: J. A. Cobano, D. Alejo, G. Heredia, S. Vera, A. Ollero
    Abstract:

    This paper addresses the problem of extending the Flight Duration of cooperative missions with multiple gliding fixed-wing UAVs by using the energy that comes from static soaring. We consider exploration missions where UAVs should pass through a set of Point of Interest (PoI) with the presence of thermals in the space. These thermals can be exploited to provide energy in terms of altitude for each gliding UAV. The objective of the mission is to extend the Flight Duration of each UAV to explore the environment without landing and decreasing the time to perform the mission. An algorithm named Bounded Recursive Heuristic Search (BRHS), based on Depth-First search techniques, is applied to the PoIs and to the UAVs. The main advantage is the real time application because of the low computational load. The paper presents a set of simulations and experiments have carried out in the airfield of La Cartuja (Seville, Spain).

  • ICRA - Multiple gliding UAV coordination for static soaring in real time applications
    2013 IEEE International Conference on Robotics and Automation, 2013
    Co-Authors: J. A. Cobano, D. Alejo, G. Heredia, S. Vera, A. Ollero
    Abstract:

    This paper addresses the problem of extending the Flight Duration of cooperative missions with multiple gliding fixed-wing UAVs by using the energy that comes from static soaring. We consider exploration missions where UAVs should pass through a set of Point of Interest (PoI) with the presence of thermals in the space. These thermals can be exploited to provide energy in terms of altitude for each gliding UAV. The objective of the mission is to extend the Flight Duration of each UAV to explore the environment without landing and decreasing the time to perform the mission. An algorithm named Bounded Recursive Heuristic Search (BRHS), based on Depth-First search techniques, is applied to the PoIs and to the UAVs. The main advantage is the real time application because of the low computational load. The paper presents a set of simulations and experiments have carried out in the airfield of La Cartuja (Seville, Spain).

  • Thermal detection and generation of collision-free trajectories for cooperative soaring UAVs
    2013 IEEE RSJ International Conference on Intelligent Robots and Systems, 2013
    Co-Authors: J. A. Cobano, D. Alejo, S. Sukkarieh, G. Heredia, A. Ollero
    Abstract:

    This paper presents a cooperative system architecture that extends the Flight Duration of multiple gliding fixed-wing Unmanned Aerial Vehicles (UAVs) for long endurance missions. The missions are defined by a set of Points of Interest (PoI) and UAVs should pass through them. A module to detect and identify thermals is implemented to exploit their energy and extend the Flight Duration, known as static soaring. A collision-free trajectory planner based on the RRT* (Optimal Rapidly-exploring Random Trees) planning algorithm is implemented. The proposed system allows applications in real time because of its low computational needs. Simulations and experiments carried out in the airfield of La Cartuja (Seville, Spain) show the performance and advantages of the proposed system.

Rui Zhang - One of the best experts on this subject based on the ideXlab platform.

  • capacity characterization of uav enabled two user broadcast channel
    arXiv: Information Theory, 2018
    Co-Authors: Qingqing Wu, Jie Xu, Rui Zhang
    Abstract:

    Although prior works have exploited the UAV's mobility to enhance the wireless communication performance under different setups, the fundamental capacity limits of UAV-enabled/aided multiuser communication systems have not yet been characterized. To fill this gap, we consider in this paper a UAV-enabled two-user broadcast channel (BC), where a UAV flying at a constant altitude is deployed to send independent information to two users at different fixed locations on the ground. We aim to characterize the capacity region of this new type of BC over a given UAV Flight Duration, by jointly optimizing the UAV's trajectory and transmit power/rate allocations over time, subject to the UAV's maximum speed and maximum transmit power constraints. First, to draw essential insights, we consider two special cases with asymptotically large/low UAV Flight Duration/speed, respectively. For the former case, it is shown that a simple hover-fly-hover (HFH) UAV trajectory with time division multiple access (TDMA) based orthogonal multiuser transmission is capacity-achieving, while in the latter case, the UAV should hover at a fixed location that is nearer to the user with larger achievable rate and in general superposition coding (SC) based non-orthogonal transmission with interference cancellation at the receiver of the nearer user is required. Next, we consider the general case with finite UAV speed and Flight Duration. We show that the optimal UAV trajectory should follow a general HFH structure, i.e., the UAV successively hovers at a pair of initial and final locations above the line segment of the two users each with a certain amount of time and flies unidirectionally between them at the maximum speed, and SC is generally needed.

  • UAV-Enabled Aerial Base Station (BS) III/III: Capacity Characterization of UAV-Enabled Two-User Broadcast Channel
    arXiv: Information Theory, 2018
    Co-Authors: Qingqing Wu, Jie Xu, Rui Zhang
    Abstract:

    Although prior works have exploited the UAV's mobility to enhance the wireless communication performance under different setups, the fundamental capacity limits of UAV-enabled/aided multiuser communication systems have not yet been characterized. To fill this gap, we consider in this paper a UAV-enabled two-user broadcast channel (BC), where a UAV flying at a constant altitude is deployed to send independent information to two users at different fixed locations on the ground. We aim to characterize the capacity region of this new type of BC over a given UAV Flight Duration, by jointly optimizing the UAV's trajectory and transmit power/rate allocations over time, subject to the UAV's maximum speed and maximum transmit power constraints. First, to draw essential insights, we consider two special cases with asymptotically large/low UAV Flight Duration/speed, respectively. For the former case, it is shown that a simple hover-fly-hover (HFH) UAV trajectory with time division multiple access (TDMA) based orthogonal multiuser transmission is capacity-achieving, while in the latter case, the UAV should hover at a fixed location that is nearer to the user with larger achievable rate and in general superposition coding (SC) based non-orthogonal transmission with interference cancellation at the receiver of the nearer user is required. Next, we consider the general case with finite UAV speed and Flight Duration. We show that the optimal UAV trajectory should follow a general HFH structure, i.e., the UAV successively hovers at a pair of initial and final locations above the line segment of the two users each with a certain amount of time and flies unidirectionally between them at the maximum speed, and SC is generally needed.

  • Capacity Characterization of UAV-Enabled Two-User Broadcast Channel
    IEEE Journal on Selected Areas in Communications, 2018
    Co-Authors: Qingqing Wu, Jie Xu, Rui Zhang
    Abstract:

    Unmanned aerial vehicles (UAVs) have recently gained growing popularity in wireless communications owing to their many advantages such as swift and cost-effective deployment, line-of-sight (LoS) aerial-to-ground link, and controllable mobility in three-dimensional (3D) space. Although prior works have exploited the UAV's mobility to enhance the wireless communication performance under different setups, the fundamental capacity limits of UAV-enabled/aided multiuser communication systems have not yet been characterized. To fill this gap, we consider, in this paper, a UAV-enabled two-user broadcast channel (BC), where a UAV flying at a constant altitude is deployed to send independent information to two users at different fixed locations on the ground. We aim to characterize the capacity region of this new type of BC over a given UAV Flight Duration, by jointly optimizing the UAV's trajectory and transmit power/rate allocations over time, subject to the UAV's maximum speed and maximum transmit power constraints. First, to draw essential insights, we consider two special cases with asymptotically large/low UAV Flight Duration/speed, respectively. For the former case, it is shown that a simple hover-fly-hover (HFH) UAV trajectory with time division multiple access (TDMA)-based orthogonal multiuser transmission is capacity-achieving; while in the latter case, the UAV should hover at a fixed location that is nearer to the user with larger achievable rate and in general superposition coding (SC)-based non-orthogonal transmission with interference cancellation at the receiver of the nearer user is required. Next, we consider the general case with finite UAV speed and Flight Duration. We show that the optimal UAV trajectory should follow a general HFH structure, i.e., the UAV successively hovers at a pair of optimal initial and final locations above the line segment connecting the two users each with a certain amount of time and flies unidirectionally between them at the maximum speed, and SC is generally needed. Furthermore, when TDMA-based transmission is considered for low-complexity implementation, we show that the optimal UAV trajectory still follows an HFH structure, but the hovering locations can only be those above the two users. Extensive simulation results are provided to verify our analysis, which also reveal useful guidelines to the practical design of UAV trajectory and communication jointly.

G. Heredia - One of the best experts on this subject based on the ideXlab platform.

  • IROS - Thermal detection and generation of collision-free trajectories for cooperative soaring UAVs
    2013 IEEE RSJ International Conference on Intelligent Robots and Systems, 2013
    Co-Authors: J. A. Cobano, D. Alejo, S. Sukkarieh, G. Heredia, A. Ollero
    Abstract:

    This paper presents a cooperative system architecture that extends the Flight Duration of multiple gliding fixed-wing Unmanned Aerial Vehicles (UAVs) for long endurance missions. The missions are defined by a set of Points of Interest (PoI) and UAVs should pass through them. A module to detect and identify thermals is implemented to exploit their energy and extend the Flight Duration, known as static soaring. A collision-free trajectory planner based on the RRT* (Optimal Rapidly-exploring Random Trees) planning algorithm is implemented. The proposed system allows applications in real time because of its low computational needs. Simulations and experiments carried out in the airfield of La Cartuja (Seville, Spain) show the performance and advantages of the proposed system.

  • Multiple gliding UAV coordination for static soaring in real time applications
    2013 IEEE International Conference on Robotics and Automation, 2013
    Co-Authors: J. A. Cobano, D. Alejo, G. Heredia, S. Vera, A. Ollero
    Abstract:

    This paper addresses the problem of extending the Flight Duration of cooperative missions with multiple gliding fixed-wing UAVs by using the energy that comes from static soaring. We consider exploration missions where UAVs should pass through a set of Point of Interest (PoI) with the presence of thermals in the space. These thermals can be exploited to provide energy in terms of altitude for each gliding UAV. The objective of the mission is to extend the Flight Duration of each UAV to explore the environment without landing and decreasing the time to perform the mission. An algorithm named Bounded Recursive Heuristic Search (BRHS), based on Depth-First search techniques, is applied to the PoIs and to the UAVs. The main advantage is the real time application because of the low computational load. The paper presents a set of simulations and experiments have carried out in the airfield of La Cartuja (Seville, Spain).

  • ICRA - Multiple gliding UAV coordination for static soaring in real time applications
    2013 IEEE International Conference on Robotics and Automation, 2013
    Co-Authors: J. A. Cobano, D. Alejo, G. Heredia, S. Vera, A. Ollero
    Abstract:

    This paper addresses the problem of extending the Flight Duration of cooperative missions with multiple gliding fixed-wing UAVs by using the energy that comes from static soaring. We consider exploration missions where UAVs should pass through a set of Point of Interest (PoI) with the presence of thermals in the space. These thermals can be exploited to provide energy in terms of altitude for each gliding UAV. The objective of the mission is to extend the Flight Duration of each UAV to explore the environment without landing and decreasing the time to perform the mission. An algorithm named Bounded Recursive Heuristic Search (BRHS), based on Depth-First search techniques, is applied to the PoIs and to the UAVs. The main advantage is the real time application because of the low computational load. The paper presents a set of simulations and experiments have carried out in the airfield of La Cartuja (Seville, Spain).

  • Thermal detection and generation of collision-free trajectories for cooperative soaring UAVs
    2013 IEEE RSJ International Conference on Intelligent Robots and Systems, 2013
    Co-Authors: J. A. Cobano, D. Alejo, S. Sukkarieh, G. Heredia, A. Ollero
    Abstract:

    This paper presents a cooperative system architecture that extends the Flight Duration of multiple gliding fixed-wing Unmanned Aerial Vehicles (UAVs) for long endurance missions. The missions are defined by a set of Points of Interest (PoI) and UAVs should pass through them. A module to detect and identify thermals is implemented to exploit their energy and extend the Flight Duration, known as static soaring. A collision-free trajectory planner based on the RRT* (Optimal Rapidly-exploring Random Trees) planning algorithm is implemented. The proposed system allows applications in real time because of its low computational needs. Simulations and experiments carried out in the airfield of La Cartuja (Seville, Spain) show the performance and advantages of the proposed system.

D. Alejo - One of the best experts on this subject based on the ideXlab platform.

  • IROS - Thermal detection and generation of collision-free trajectories for cooperative soaring UAVs
    2013 IEEE RSJ International Conference on Intelligent Robots and Systems, 2013
    Co-Authors: J. A. Cobano, D. Alejo, S. Sukkarieh, G. Heredia, A. Ollero
    Abstract:

    This paper presents a cooperative system architecture that extends the Flight Duration of multiple gliding fixed-wing Unmanned Aerial Vehicles (UAVs) for long endurance missions. The missions are defined by a set of Points of Interest (PoI) and UAVs should pass through them. A module to detect and identify thermals is implemented to exploit their energy and extend the Flight Duration, known as static soaring. A collision-free trajectory planner based on the RRT* (Optimal Rapidly-exploring Random Trees) planning algorithm is implemented. The proposed system allows applications in real time because of its low computational needs. Simulations and experiments carried out in the airfield of La Cartuja (Seville, Spain) show the performance and advantages of the proposed system.

  • Multiple gliding UAV coordination for static soaring in real time applications
    2013 IEEE International Conference on Robotics and Automation, 2013
    Co-Authors: J. A. Cobano, D. Alejo, G. Heredia, S. Vera, A. Ollero
    Abstract:

    This paper addresses the problem of extending the Flight Duration of cooperative missions with multiple gliding fixed-wing UAVs by using the energy that comes from static soaring. We consider exploration missions where UAVs should pass through a set of Point of Interest (PoI) with the presence of thermals in the space. These thermals can be exploited to provide energy in terms of altitude for each gliding UAV. The objective of the mission is to extend the Flight Duration of each UAV to explore the environment without landing and decreasing the time to perform the mission. An algorithm named Bounded Recursive Heuristic Search (BRHS), based on Depth-First search techniques, is applied to the PoIs and to the UAVs. The main advantage is the real time application because of the low computational load. The paper presents a set of simulations and experiments have carried out in the airfield of La Cartuja (Seville, Spain).

  • ICRA - Multiple gliding UAV coordination for static soaring in real time applications
    2013 IEEE International Conference on Robotics and Automation, 2013
    Co-Authors: J. A. Cobano, D. Alejo, G. Heredia, S. Vera, A. Ollero
    Abstract:

    This paper addresses the problem of extending the Flight Duration of cooperative missions with multiple gliding fixed-wing UAVs by using the energy that comes from static soaring. We consider exploration missions where UAVs should pass through a set of Point of Interest (PoI) with the presence of thermals in the space. These thermals can be exploited to provide energy in terms of altitude for each gliding UAV. The objective of the mission is to extend the Flight Duration of each UAV to explore the environment without landing and decreasing the time to perform the mission. An algorithm named Bounded Recursive Heuristic Search (BRHS), based on Depth-First search techniques, is applied to the PoIs and to the UAVs. The main advantage is the real time application because of the low computational load. The paper presents a set of simulations and experiments have carried out in the airfield of La Cartuja (Seville, Spain).

  • Thermal detection and generation of collision-free trajectories for cooperative soaring UAVs
    2013 IEEE RSJ International Conference on Intelligent Robots and Systems, 2013
    Co-Authors: J. A. Cobano, D. Alejo, S. Sukkarieh, G. Heredia, A. Ollero
    Abstract:

    This paper presents a cooperative system architecture that extends the Flight Duration of multiple gliding fixed-wing Unmanned Aerial Vehicles (UAVs) for long endurance missions. The missions are defined by a set of Points of Interest (PoI) and UAVs should pass through them. A module to detect and identify thermals is implemented to exploit their energy and extend the Flight Duration, known as static soaring. A collision-free trajectory planner based on the RRT* (Optimal Rapidly-exploring Random Trees) planning algorithm is implemented. The proposed system allows applications in real time because of its low computational needs. Simulations and experiments carried out in the airfield of La Cartuja (Seville, Spain) show the performance and advantages of the proposed system.