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A collision avoiding system and a method of safety flying is proposed in this paper for Unmanned Air Vehicles (UAV). The UAV accesses the data from various sensors mounted on board and thus calculates the risks factors for any impending collision. An algorithm for decision making in order to avoid collision is presented in this paper as a pseudo code. Based on the measured as well as estimated risk...
In this paper, a method to calculate alerting thresholds is outlined along with the assumptions and an example. First, the definitions and recommendations of the FAA sponsored Sense-and-Avoid (SAA) workshop report has been adapted to a formal mathematical definition. These definitions are then realized using assumptions and other logic and are translated into a more concrete SAA scenarios. Alerting...
This paper presents a methodology based on a variation of the Rapidly-exploring Random Trees (RRTs) that generates feasible trajectories for autonomous vehicles with holonomic constraints in environments with obstacles. Our approach is based on seventh order Bézier curves to connect vertexes of the tree, generating paths that do not violate the main kinematic constraints of the vehicle. The methodology...
The utilization of unmanned aerial vehicles requires the ability to navigate in urban or unknown terrain where many moving and/or stationary obstacles of different types and sizes may endanger the safety of the mission. Large efforts have been addressed to resolve conflicts to unmanned aircraft. This paper explores the fundamental concept and presents an up-to-date survey of the collision sensing,...
This paper presents an innovative 3D analytical algorithm for the resolution of the pair-wise non-cooperative collision avoidance problem between aircrafts. The proposed algorithm addresses the above described problem by using an innovative approach, based on the consideration of a cylindrical safety bubble, and it is able to obtain an optimal three-dimensional analytical solution for this problem...
This paper presents a computational framework of partitioning a dynamical system's free space in a way such that global optimality can be guaranteed by composing control policies over a local region. Unlike traditional triangulation methods, the partition method in this paper takes into account the topological layout, as well as the vehicle dynamics. With this framework, we show that spatial, dynamic...
This paper presents path planning algorithms using Rapidly-exploring Random Trees (RRTs) to generate paths for multiple unmanned air vehicles (UAVs) in real time, from given starting locations to goal locations in the presence of static, pop-up and dynamic obstacles. Generating non-conflicting paths in obstacle rich environments for a group of UAVs within a given short time window is a challenging...
This paper presents a methodology based on a variation of the Rapidly-exploring Random Trees (RRTs) that generates feasible trajectories for autonomous aerial vehicles with holonomic constraints in environments with obstacles. Our approach uses Pythagorean Hodograph (PH) curves to connect vertices of the tree, which makes it possible to generate paths for which the main kinematic constraints of the...
Flying multiple unmanned aircraft in the same airspace and instances or operating these aircraft in commercial airspace increases the likelihood of collisions. To facilitate the continuing growth of air traffic and the request for more operational flexibility a more advanced form of collision avoidance will be required. This paper, addresses the problem of solving conflicts raised between unmanned...
This paper presents a collision avoidance method for multiple UAVs and other non-cooperative aircraft based on velocity planning and taking into account the trajectory prediction under uncertainties. The proposed method finds a safe trajectory from the predicted trajectory modifying the velocity profile of the different co-operative vehicles involved in the collision. A particle filter is used to...
This paper is concerned with the coordinated flight of two autonomous UAVs to be used for aerobiological sampling of biological threat agents above agricultural fields. The periodic sampling task involves two phases: a sampling interval and an initialization interval. During the sampling interval, both vehicles must employ their aerobiological sampling devices and follow a precise ground track in...
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