Now showing items 77-96 of 113

    • On the Existence and Synthesis of Curvature-Bounded Paths Inside Nonuniform Rectangular Channels 

      Cowlagi, Raghvendra V.; Tsiotras, Panagiotis (Georgia Institute of TechnologyIEEE, 2010)
      Motion planners for autonomous mobile vehicles that are based on rectangular cell decompositions are often required to construct kinematically feasible path – typically curvature-bounded paths – traversing rectangular ...
    • 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 ...
    • 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 ...
    • An Optimal Evader Strategy in a Two-Pursuer One-Evader Problem 

      Sun, Wei; Tsiotras, Panagiotis (Georgia Institute of Technology, 2014-12)
      We consider a relay pursuit-evasion problem with two pursuers and one evader. We reduce the problem to a one-pursuer/one-evader problem subject to a state constraint. A suboptimal control strategy for the evader to prolong ...
    • Optimal Feedback Guidance of a Small Aerial Vehicle in the Presence of Stochastic Wind 

      Anderson, Ross P.; Bakolas, Efstathios; Milutinović, Dejan; Tsiotras, Panagiotis (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, 2013)
      The navigation of a small unmanned aerial vehicle is challenging due to a large influence of wind to its kinematics. When the kinematic model is reduced to two dimensions, it has the form of the Dubins kinematic vehicle ...
    • Optimal Motion Planning with the Half-Car Dynamical Model for Autonomous High-Speed Driving 

      Cowlagi, Raghvendra V.; Peters, Steven C.; Karaman, Sertac; Frazzoli, Emilio; Tsiotras, Panagiotis; Iagnemma, Karl; Jeong Hwan, Jeon (Georgia Institute of Technology, 2013-06)
      We discuss an implementation of the RRT* optimal motion planning algorithm for the half-car dynamical model to enable autonomous high-speed driving. To develop fast solutions of the associated local steering problem, we ...
    • Optimal Pursuit of Moving Targets using Dynamic Voronoi Diagrams 

      Bakolas, Efstathios; Tsiotras, Panagiotis (Georgia Institute of TechnologyIEEE, 2010)
      We consider Voronoi-like partitions for a team of moving targets distributed in the plane, such that each set in this partition is uniquely associated with a particular moving target in the following sense: a pursuer ...
    • Optimal Synthesis of the Zermelo–Markov–Dubins Problem in a Constant Drift Field 

      Bakolas, Efstathios; Tsiotra, Panagiotis (Georgia Institute of TechnologySpringer Verlag, 2012-01-16)
      We consider the optimal synthesis of the Zermelo–Markov–Dubins problem, that is, the problem of steering a vehicle with the kinematics of the Isaacs–Dubins car in minimum time in the presence of a drift field. By using ...
    • Performance of a Monocular Vision-aided Inertial Navigation System for a Small UAV 

      Magree, Daniel; Johnson, Eric N. (Georgia Institute of Technology, 2013-08)
      The use of optical sensors for navigation on aircraft has receive much attention recently. Optical sensors provide a wealth of information about the environment and are standard payloads for many unmanned aerial vehicles ...
    • Pose-Tracking Controller for Satellites with Time-Varying Inertia 

      Filipe, Nuno; Holzinger, Marcus J.; Tsiotras, Panagiotis (Georgia Institute of Technology, 2014-06)
      Satellite proximity operations have been identified by NASA and the USAF as a crucial technology that could enable a series of new missions in space. Such missions would require a satellite to simultaneously and accurately ...
    • Preliminary Evaluation of Rapidly-Exploring Random Trees for Sling-Load Flight Guidance 

      Johnson, Eric N.; Mooney, John G. (Georgia Institute of Technology, 2013)
      A novel approach to providing guidance for helicopters with under-slung loads is presented. Rapidly-exploring Ran- dom Trees are adapted to plan trajectories for simplified helicopter-load models. The algorithm is presented ...
    • A Process to Obtain Robustness Metrics for Adaptive Flight Controllers 

      Kimbrell, Scott; Johnson, Eric N.; Chowdhary, Girish; Calise, Anthony J.; Chandramohan, Rajeev (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, 2009-08)
      This research effort seeks a process to draw parallels between the classical stability metrics of gain and phase margins for classical linear control systems with stability margins for adaptive controllers. The method ...
    • 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 ...
    • 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 ...
    • Real-Time Vision-Based Relative Aircraft Navigation 

      Johnson, Eric N.; Calise, Anthony J.; Watanabe, Yoko; Ha, Jin-Cheol; Neidhoefer, James C. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2007-03)
      This paper describes two vision-based techniques for the navigation of an aircraft relative to an airborne target using only information from a single camera fixed to the aircraft. These techniques are motivated by ...
    • Relay Pursuit of a Maneuvering Target Using Dynamic Voronoi Diagrams 

      Bakolas, Efstathios; Tsiotras, Panagiotis (Georgia Institute of TechnologyInternational Federation of Automatic Control (IFAC)Elsevier, 2012-08)
      This paper addresses the problem of the pursuit of a maneuvering target by a group of pursuers distributed in the plane. This pursuit problem is solved by associating it with a Voronoi-like partitioning problem that ...
    • Rigid body motion tracking without linear and angular velocity feedback using dual quaternions 

      Filipe, Nuno; Tsiotras, Panagiotis (Georgia Institute of Technology, 2013-06)
      This paper takes advantage of a new, recently proposed representation of the combined translational and rotational dynamic equations of motion of a rigid body in terms of dual quaternions. We show that combined position ...
    • Robust Feature Detection, Acquisition and Tracking for Relative Navigation in Space with a Known Target 

      Cho, Dae-Min; Tsiotras, Panagiotis; Zhang, Guangcong; Holzinger, Marcus J. (Georgia Institute of Technology, 2013-08)
      Recent advances in robotics and computer vision have enabled the implementation of sophisticated vision-based relative navigation algorithms for robotic spacecraft using a single calibrated monocular camera. These techniques, ...
    • Self-Contained Autonomous Indoor Flight with Ranging Sensor Navigation 

      Chowdhary, Girish; Sobers, D. Michael, Jr.; Pravitra, Chintasid; Christmann, Hans Claus; Wu, Allen; Hashimoto, Hiroyuki; Ong, Chester; Kalghatgi, Roshan; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, 2012-11)
      This paper describes the design and flight test of a completely self-contained autonomous indoor Miniature Unmanned Aerial System (M-UAS). Guidance, navigation, and control algorithms are presented, enabling the M-UAS ...
    • A Sequential Pursuer-Target Assignment Problem Under External Disturbances 

      Sun, Wei; Tsiotras, Panagiotis (Georgia Institute of Technology, 2013-12)
      In this paper we deal with the problem of a team of pursuers distributed in the plane subject to an environmental disturbance (e.g., wind). The objective of the pursuers is to intercept a moving target which is not affected ...