Now showing items 21-40 of 104

    • Beyond Quadtrees: Cell Decomposition for Path Planning using the Wavelet Transform 

      Cowlagi, Raghvendra V.; Tsiotras, Panagiotis (Georgia Institute of TechnologyIEEE, 2007-12)
      Path planning techniques based on hierarchical multiresolution cell decompositions are suitable for online implementation due to their simplicity and speed of implementation. We present an efficient multiresolution cell ...
    • Multiresolution Path Planning Via Sector Decompositions Compatible to On-Board Sensor Data 

      Bakolas, Efstathios; Tsiotras, Panagiotis (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2008)
      In this paper we present a hybrid local-global path planning scheme for the problem of operating a moving agent inside an unknown environment in a collision-free manner. The path planning algorithm is based on information ...
    • On-line Path Generation for Small Unmanned Aerial Vehicles using B-Spline Path Templates 

      Jung, Dongwon; Tsiotras, Panagiotis (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2008)
      In this study we investigate the problem of generating a smooth, planar reference path, given a family of discrete optimal paths. In conjunction with a path representation by a finite sequence of square cells, the generated ...
    • Multiresolution On-Line Path Planning for Small Unmanned Aerial Vehicles 

      Jung, Dongwon; Tsiotras, Panagiotis (Georgia Institute of TechnologyIEEE, 2008)
      In this article we propose a new online multiresolution path planning algorithm for a small unmanned air vehicle (UAV) with limited on-board computational resources. The proposed approach assumes that the UAV has ...
    • Multiresolution Path Planning with Wavelets: A Local Replanning Approach 

      Cowlagi, Raghvendra V.; Tsiotras, Panagiotis (Georgia Institute of TechnologyIEEE, 2008)
      A path planning algorithm based on multiresolution cell decomposition of the environment using wavelets is proposed. The environment is assumed to be given by an occupancy grid at fine resolution. The algorithm constructs ...
    • Flight Test Results of Autonomous Fixed-Wing Transition to and from Stationary Hover 

      Johnson, Eric N.; Turbe, Michael A.; Wu, Allen D.; Kannan, Suresh K.; Neidhoefer, James C. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, 2008-03)
      Linear systems can be used to adequately model and control an aircraft in either ideal steady-level flight or in ideal hovering flight. However, constructing a single unified system capable of adequately modeling or ...
    • Guidance, Navigation, Control, and Operator Interfaces for Small Rapid Response Unmanned Helicopters 

      Christmann, Hans Claus; Christophersen, Henrik B.; Wu, Allen D.; Johnson, Eric N. (Georgia Institute of Technology, 2008-04)
      This paper focuses on the development of small rapid response reconnaissance unmanned helicopters (1 to 3 kg, electric), for use by the military in urban areas and by civilian first responders, in terms of system ...
    • Bank-to-Turn Control for a Small UAV using Backstepping and Parameter Adaptation 

      Jung, Dongwon; Tsiotras, Panagiotis (Georgia Institute of Technology, 2008-07)
      In this research we consider the problem of path following control for a small fixed-wing unmanned aerial vehicle (UAV). Assuming the UAV is equipped with an autopilot for low level control, we adopt a kinematic error ...
    • Methods for Localization and Mapping Using Vision and Inertial Sensors 

      Wu, Allen D.; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2008-08)
      The problems of vision-based localization and mapping are currently highly active areas of research for aerial systems. With a wealth of information available in each image, vision sensors allow vehicles to gather data ...
    • UAS Reference Scenarios for MANET Development 

      Christmann, Hans Claus; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2008-08)
      After autonomous flight for Unmanned Aerial Vehicles (UAVs) has been accomplished, research was stipulated to look into application related challenges in connection with Unmanned Aerial Systems (UAS). As one possible ...
    • Real-time Implementation and Validation of a New Hierarchical Path Planning Scheme for UAVs via Hardware-in-the-Loop Simulation 

      Jung, Dongwon; Ratti, Jayant; Tsiotras, Panagiotis (Georgia Institute of TechnologySpringer Verlag, 2009)
      We develop a hierarchical path planning and control algorithm for a small fixed-wing UAV. Incorporating the hardware-in-the-loop (HIL) simulation environment, the hierarchical path planning and control algorithm has been ...
    • On the Generation of Nearly Optimal, Planar Paths of Bounded Curvature and Curvature Gradient 

      Bakolas, Efstathios; Tsiotras, Panagiotis (Georgia Institute of TechnologyIEEE, 2009)
      We present a numerically efficient scheme to generate a family of path primitives that can be used to construct paths that take into consideration point-wise constraints on both the curvature and its derivative. The ...
    • The Asymmetric Sinistral/Dextral Markov-Dubins Problem 

      Bakolas, Efstathios; Tsiotras, Panagiotis (Georgia Institute of TechnologyIEEE, 2009)
      We consider a variation of the classical Markov-Dubins problem dealing with curvature-constrained, shortest paths in the plane with prescribed initial and terminal positions and tangents, when the lower and upper bounds ...
    • Georgia Tech Aerial Robotics Team: 2009 International Aerial Robotics Competition Entry 

      Chowdhary, Girish; Christmann, Hans Claus; Johnson, Eric N.; Salaün, Erwan; Sobers, D. Michael Jr. (Georgia Institute of Technology, 2009-07)
      This paper examines the use of low-cost range and target identification sensors on a stable flying vehicle for suitability in solving the 5th Mission proposed for the 2009 International Aerial Robotics Competition. The ...
    • An ILS Inspired Approach and Departure System Utilizing Monocular Vision 

      Christmann, Hans Claus; Johnson, Eric N. (Georgia Institute of Technology, 2009-07)
      This paper introduces a simple system to provide relative position between a base unit and an active unit. The proposed system is directional and allows the active unit to approach or depart from the base unit along a ...
    • A Language for Describing Agent Behavior as Hybrid Models 

      Kannan, Suresh K.; Christmann, Hans Claus; Lee, Seungman; Johnson, Eric N.; Kim, So Y. K (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, 2009-08)
      Air Traffic conflict detection and resolution (CDR) involves multiple domains, the modeling of physical systems such as aircraft, encoding conflict detection algorithms as well as the procedures(tasks) for conflict ...
    • Indoor Navigation for Unmanned Aerial Vehicles 

      Sobers, D. Michael Jr.; Chowdhary, Girish; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, 2009-08)
      The ability for vehicles to navigate unknown environments is critical for autonomous operation. Mapping of a vehicle's environment and self-localization within that environment are especially difficult for an Unmanned ...
    • Flight Test Validation of a Neural Network based Long Term Learning Adaptive Flight Controller 

      Chowdhary, Girish; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2009-08)
      The purpose of this paper is to present and analyze flight test results of a Long Term Learning Adaptive Flight Controller implemented on a rotorcraft and a fixed wing Unmanned Aerial Vehicle. The adaptive control ...
    • Real-Time System Identification of a Small Multi-Engine Aircraft 

      DeBusk, Wesley M.; Chowdhary, Girish; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2009-08)
      In-flight identification of an aircraft's dynamic model can benefit adaptive control schemes by providing estimates of aerodynamic stability derivatives in real time. This information is useful when the dynamic model ...
    • 3D Obstacle Detection Using a Single Camera 

      Shah, Syed Irtiza Ali; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2009-08)
      This paper aims at detecting obstacles using a single camera in an unknown three dimensional world, for 3D motion of an unmanned air vehicle. Obstacle detection is a pre-requisite for collision-free motion of a UAV through ...