Now showing items 34-50 of 50

    • 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 ...
    • Modeling Urban Environments for Communication-Aware UAV Swarm Path Planning 

      Christmann, Hans Claus; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2010-08)
      The presented work introduces a graph based approach to model urban (or otherwise cluttered) environments for UAS utilization beyond line-of-sight as well as out of direct R/F range of the operator's control station. ...
    • Modeling, Control, and Flight Testing of a Small Ducted Fan Aircraft 

      Johnson, Eric N.; Turbe, Michael A. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2006-07)
      Small ducted fan autonomous vehicles have potential for several applications, especially for missions in urban environments. This paper discusses the use of dynamic inversion with neural network adaptation to provide an ...
    • Nested Saturation with Guaranteed Real Poles 

      Johnson, Eric N.; Kannan, Suresh K. (Georgia Institute of TechnologyIEEE, 2003-06)
      The global stabilization of asymptotically null-controllable linear systems with bounded controls has been studied extensively. An early contribution was by Teel [6] who proposed a set of nested saturators to globally ...
    • Neural Network Augmented Kalman Filtering in the Presence of Unknown System Inputs 

      Sattigeri, Ramachandra J.; Calise, Anthony J. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2006-08)
      We present an approach for augmenting a linear, time-varying Kalman filter with an adaptive neural network (NN) for the state estimation of systems with linear process models acted upon by unknown inputs. The application ...
    • Neural-Network Augmentation of Existing Linear Controllers 

      Sharma, Manu; Calise, Anthony J. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2005-01)
      A method to augment existing linear controllers with a multilayer neural network is presented. The neural network is adapted online to ensure desired closed-loop response in the face of parametric plant uncertainty; ...
    • 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 ...
    • Small Adaptive Flight Control Systems for UAVs Using FPGA/DSP Technology 

      Christophersen, Henrik B.; Pickell, Wayne J.; Koller, Adrian A.; Kannan, Suresh K.; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2004-09)
      Future small UAVs will require enhanced capabilities like seeing and avoiding obstacles, tolerating unpredicted flight conditions, interfacing with payload sensors, tracking moving targets, and cooperating with other ...
    • System Integration and Operation of a Research Unmanned Aerial Vehicle 

      Johnson, Eric N.; Schrage, Daniel P. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2004-01)
      The use of flight simulation tools to reduce the schedule, risk, and required amount of flight testing for complex aerospace systems is a well-recognized benefit of these approaches. However, some special challenges arise ...
    • 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 ...
    • Vision-Aided Inertial Navigation for Flight Control 

      Wu, Allen D.; Johnson, Eric N.; Proctor, Alison A. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2005-09)
      Many onboard navigation systems use the Global Positioning System to bound the errors that result from integrating inertial sensors over time. Global Positioning System information, however, is not always accessible since ...
    • Vision-based Target Tracking with Adaptive Target State Estimator 

      Sattigeri, Ramachandra J.; Johnson, Eric N.; Calise, Anthony J.; Ha, Jin-Cheol (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2007-08)
      This paper presents an approach to vision-based target tracking with a neural network (NN) augmented Kalman filter as the adaptive target state estimator. The vision sensor onboard the follower (tracker) aircraft is a ...
    • Vision-Only Aircraft Flight Control 

      De Wagter, Christophe; Proctor, Alison A.; Johnson, Eric N. (Georgia Institute of Technology, 2003-10)
      Building aircraft with navigation and control systems that can complete flight tasks is complex, and often involves integrating information from multiple sensors to estimate the state of the vehicle. This paper describes ...
    • Visual Marker Detection In The Presence Of Colored Noise for Unmanned Aerial Vehicles 

      Shah, Syed Irtiza Ali; Wu, Allen D.; Johnson, Eric N. (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2010-04)
      This paper develops a vision-based algorithm to detect a visual marker in real time and in the presence of excessive colored noise for Unmanned Aerial Vehicles. After using various image analysis techniques, including ...
    • Visual Search Automation for Unmanned Aerial Vehicles 

      Johnson, Eric N.; Proctor, Alison A.; Ha, Jin-Cheol; Tannenbaum, Allen R. (Georgia Institute of TechnologyIEEE, 2005-01)
      This paper describes the design, development, and testing of an Unmanned Aerial Vehicle (UAV) with automated capabilities: searching a prescribed area, identifying a specific building within that area based on a small ...
    • Vortex Model Based Adaptive Flight Control Using Synthetic Jets 

      Muse, Jonathan A.; Tchieu, Andrew A.; Kutay, Ali T.; Chaundramohan, Rajeev; Leonard, Anthony (Georgia Institute of TechnologyAmerican Institute of Aeronautics and Astronautics, Inc., 2009-08)
      A simple low-order model is derived for developing flight control laws for controlling the longitudinal dynamics of an aircraft using synthetic jet type actuators. Bi-directional changes in the pitching moment over a ...