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This paper develops mobility control strategies for robotic agents to provide quality of service of information while carrying out active sensing tasks. Like wireless communication concepts of quality of service, a new metric is developed to encapsulate an aggregate measure of information gathering as a network service. This metric states that a given amount of information will be achieved in given...
The problems of area patrol, perimeter surveillance, and target tracking are combined into a single reconnaissance framework. This integration is based on application of ordered upwind methods to track the propagation of the target position boundary. The ordered upwind methods provide a computationally efficient method for computing the target track boundary over a discretized nonuniform mesh of the...
This paper presents a vision-based navigation solution for unmanned aircraft operations on airfield surfaces in GPS-denied environments. The unmanned aircraft system ground operations management system (UGOMS) described here combines measurements from a computer vision system and inertial sensors with an airport layout database to provide real-time position determination on the airfield surface. UGOMS...
This paper presents a system for in situ atmospheric sensing using an aerial robot system in the presence of a strong wind field. The geostatistical concept of the variogram is used to characterize regions of the environment with high variability, which is assumed to correlate with scientific interest. After regions of interest are identified, ordered upwind methods are used to generate feasible trajectories...
This paper presents an approach to approximate information content for active sensing tasks. The unscented transform is used to represent probability distributions by a set of representative sample points that capture the first and second moments of the distribution. Using these sample points, the effects of nonlinear operators on a probability distribution of active sensing costs can be approximated...
This paper presents a hierarchical control architecture that enables cooperative surveillance by a heterogeneous aerial robot network comprised of mothership unmanned aircraft and daughtership micro air vehicles. Combining the endurance, range, and processing capabilities of the motherships with the stealth, flexibility, and maneuverability of swarms of daughterships enables robust control of aerial...
This paper presents a new task assignment algorithm that integrates area search and target tracking. A new tracking metric is derived that encodes the ability of each robot to reach an unsensed target before the uncertainty in its position passes a given upper bound. Target activation and tracking assignment using this method enable broader participation by individual robots in a cooperative surveillance...
This paper explores the role of meshed airborne communication networks in the operational performance of small unmanned aircraft systems. Small unmanned aircraft systems have the potential to create new applications and markets in civil domains, enable many disruptive technologies, and put considerable stress on air traffic control systems. We argue that of the existing networked communication architectures,...
This paper presents results implementing Lyapunov vector fields for the guidance of unmanned aircraft. The vector fields yield globally stable tracking of circular loiter patterns. These loiter patterns are used in several unmanned aircraft applications including hierarchical micro air vehicle control for cooperative plume tracking, extremum seeking for electronic chaining, and cooperative tracking...
This paper presents a coordination scheme for standoff tracking of an uncertain moving target by cooperating mobile robots with range and bearing sensors. An algorithm is described that transforms a guidance vector field developed for loitering about circular patterns into a vector field that tracks ellipses. Specific elliptical tracking patterns are developed based on the covariance matrix of a stochastic...
This paper presents a framework for receding horizon control under measurement or sensor uncertainty. Concepts from optimal input design (OID) are combined with the unscented transform (UT) developed for nonlinear estimation. UT algorithms represent probability distributions by a set of representative sample points that capture the first and second moments of the distribution. Using these sample points,...
A decentralized mobility control scheme, using extremum seeking methods, is presented that forms a linked chain of mobile relays, having nonholonomic constraints, that maximizes the total link bandwidth. The factors that determine the final arrangement are numerous and hard to model and predict in real time. Thus controlling the mobile nodes by position alone to form a linked communication chain is...
In this paper we investigate the establishment and maintenance of a delay tolerant network through decentralized mobility control. A set of geographically dispersed wireless radio nodes wish to communicate with one another. These nodes are free to move about the environment and are not constrained to remain in direct communication range of one another. A second set of helper nodes exist in the environment...
This paper presents an integrated vision-based navigation system for small autonomous aircraft. Previously developed sensor fusion algorithms based on the unscented Kalman filter (UKF) are combined with an adaptive receding horizon controller (ARHC) for guidance. Control and planning horizons are computed based on the sensor range and the effective speed of the UAV, which is computed as a weighted...
This paper presents a comparison of lateral controllers for vision-based control of a small autonomous aircraft following a road. Control strategies are designed to stabilize the aircraft lateral control using only the vision measurements and inertial sensors. Methods compared here include several aim-ahead controllers, sliding surface controllers, linear quadratic Gaussian (LQG) regulators, and a...
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