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The Intelligent Tasker was developed to provide dynamic retasking of autonomous coordinated aerial assets to accommodate “pop-up” points of interest and the loss of a team member during a coordinated mission. The system was implemented in MATLAB and can be integrated with various ground stations. The user interface and backend GA Optimizer make planning and executing an optimized coordinated mission...
(Semi-) autonomous complex UAV missions, such as inspection or search-and-rescue in uncertain dynamic environments, require obstacle avoidance and operator shared control. Combining humans' cognitive abilities with fast automation is the key for such missions. This paper presents a flight control system architecture based on the instantaneous Task Specification using Constraints (iTaSC) methodology...
This article presents a concept for scalable autonomy of UAVs applicable to the field of reconnaissance missions. Level of autonomy can be defined along the amount of human independence. Low human independence allows detailed control, while adding to the workload. Higher human independence provides functionalities inflicting less workload, but hides information from the pilot or inhibits from interacting...
This paper proposes a bidirectional spline-RRT∗ path planning algorithm for fixed-wing unmanned aerial vehicles (UAVs). The proposed algorithm combines the basic RRT∗ algorithm with the spline method to produce smooth paths, which are essential for fixed-wing UAVs. The proposed bidirectional spline-RRT∗ algorithm generates paths satisfying approach direction constraints on both start and goal points,...
We present a two step path planning algorithm for unmanned aerial vehicles (UAVs) with kinematic constraints in the presence of polygonal obstacles. We use a visibility graph representation for the environment and a Dubins vehicle approximation to model UAV kinematics. A modified Dijkstra's shortest path algorithm is developed as first step of our approach to plan paths for a UAV. The algorithm in...
This paper considers the problem of integrating unmanned aircraft into low altitude airspace above urban environments, including major terminal areas and helicopter landing sites. A simple set of data-driven modelling techniques are used to explore, visualise and assess existing air traffic in a manner more informative to the unmanned aircraft community. First, low altitude air traffic data sets (position...
This article addresses an important path planning problem for robots and Unmanned Aerial Vehicles (UAVs) which aims to find a shortest path of bounded curvature passing through a given sequence of target points on a ground plane. Currently, there is no algorithm that can compute an optimal solution to this problem. Therefore, tight lower bounds are vital in determining the quality of any feasible...
A planar path planner for a persistent surveillance application in the presence of static obstacles is developed for a team of homogeneous unmanned aircraft systems (UAS). The role of the team is to provide complete coverage (sensor data or image acquisition) of a user designated area within a specified period. A two stage planner is chosen so that vehicle maneuver constraints can be satisfied in...
Dynamic characteristics of an actuator generally cause a deterioration of control performance because it has a time-lag element. If a control system is designed without considering the actuator dynamics, it cannot guarantee sufficient control performance or stability of a system. In conventional researches, the dynamic characteristics are treated as a modeling error when designing a robust controller...
This paper presents the development of a 3D obstacle avoidance algorithm for Unmanned Aerial Vehicle (UAV) system. The avoidance algorithm works by generating avoiding waypoints, within the original predefined waypoints, when the vehicle faces obstacles obstructing its flightpath. The proposed approach bases its algorithm on the utilization of ellipsoid geometry for defining a restricted zone containing...
This paper describes a vision-based multiple model adaptive estimation using UAVs that enables the tracking of a mobile target that changes the system model depending on unknown factors. In our system the machine-learning-based target identification method uses Haar-like classifiers that detects the target position. The system uses multiple extended Kalman filters for each system model and estimates...
An algorithm was developed for the formation flight of a team of fixed-wing aircraft to follow a desired trajectory described in terms of given waypoints. In-flight formation change can be commanded at set points along the trajectory or on demand. The algorithm makes use of the Hungarian algorithm for formation position assignment in a local tangent coordinate system. Trajectories of the aircraft...
A special class of fixed-wing UAVs called agile UAVs have emerged recently, that are lightweight with control surfaces as big as 50% chord capable of deflecting up to 50 deg., and are characterized by high thrust-to-weight ratios of around 2–3, and a strong propwash. Such configuration allows agile UAVs to perform extreme aerobatic maneuvers that expand the conventional flight envelope to cover the...
In this paper we propose a model of zero-sum differential games (ZSG) to perform the formation flight of a group of three fixed-wing Unmanned Aerial Vehicles (UAVs). The dynamics of these UAVs are described in the linearized model around nominal values. For the formation strategy, the game scheme for one of the UAVs acts as the leader vehicle following a freely designed trajectory meanwhile the two...
The communication link integrity of an Unmanned Aerial System (UAS) is influenced by a number of factors, the most relevant being antenna radiation pattern and gain, receiver sensitivity, output power, terrain relief, aircraft's attitude and trajectory, and frequency band. The constraints are especially severe in the context of beyond line-of-sight and low altitude flight plan. This work presents...
Aircraft systems are the integral part of the naval operations. These systems have been making great contribution to all kind of naval tasks and operations since previous century. On the other hand, developments in Unmanned Aircraft Systems make Naval Forces replace manned aircraft systems with unmanned ones. Consequently, utilization of Unmanned Air Craft Systems in maritime domain contributes to...
Multi-rotor Unmanned Aerial Vehicles make use of multiple propellers, mounted on arms, to produce the required lift. This article investigates the influence on propulsion system efficiency in hover due to the configuration of these propellers. Influence of pusher or puller configuration of the propeller, number of blades, shape and dimensions of the arm, coaxial and overlapping propellers, is presented...
An optimal design method for generating a flight path passing through specified waypoints while satisfying the task points sent by the ground operators is proposed in this paper. Each specified waypoint is reached exactly at the specified location and time while intermediate waypoints are generated in such a way that they satisfy the task points, with highest benefit measure, i.e., satisfying tasks...
Sense and Avoid (SAA) has been identified as one of the crucial technologies for UAV safety flight. The SAA systematic design is to develop a system with sensor configuration and SAA algorithms. Normally, the SAA system integration and test can be both expensive and dangerous without carefully system and algorithms development. In this paper, we proposed a software based SAA simulation framework for...
This paper concerns a distributed control approach of a fleet of Unmanned Aerial Vehicles (UAVs) based on a Leaderless strategy. The independent distributed particle swarm Optimization algorithms are used to develop this approach. The goal is to get a set of UAVs to fly on a 2D plane while converging to a predefined spatial configuration around a rendezvous point. The developed method would be applied...
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