UAV Navigation using Local Computational Resources : Keeping a target in sight

Sammanfattning: When tracking a moving target, an Unmanned Aerial Vehicle (UAV) mustkeep the target within its sensory range while simultaneously remaining awareof its surroundings. However, small flight computers must have sufficientenvironmental knowledge and computational capabilities to provide real-timecontrol to function without a ground station connection. Using a Raspberry Pi4 model B, this thesis presents a practical implementation for evaluating pathplanning generators in the context of following a moving target. The practicalmodel integrates two waypoint generators for the path planning scenario: A'and 3D Vector Field Histogram' (3DVFH'). The performances of the pathplanning algorithms are evaluated in terms of the required processing time,distance from the target, and memory consumption. The simulations are runin two types of environments. One is modelled by hand with a target walkinga scripted path. The other is procedurally generated with a random walker.The study shows that 3DVFH' produces paths that follow the moving targetmore closely when the actor follows the scripted path. With a random walker,A' consistently achieves the shortest distance. Furthermore, the practicalimplementation shows that the A' algorithm’s persistent approach to detectand track objects has a prohibitive memory requirement that the Raspberry Pi4 with a 2GBRAMcannot handle. Looking at the impact of object density, the3DVFH' implementation shows no impact on distance to the moving target,but exhibits lower execution speeds at an altitude with fewer obstacles to detect.The A' implementation has a marked impact on execution speeds in the formof longer distances to the target at altitudes with dense obstacle detection.This research project also realized a communication link between thepath planning implementations and a Geographical Information System (GIS)application supported by the Carmenta Engine SDK to explore how locallystored geospatial information impact path planning scenarios. Using VMapgeospatial data, two levels of increasing geographical resolution werecompared to show no performance impact on the planner processes, but asignificant addition in memory consumption. Using geospatial informationabout a region of interest, the waypoint generation implementations are ableto query the map application about the legality of its current position.