The Quadrotor Platform : from a military point of view

Sammanfattning: The use of military UAV’s has become increasingly popular amongst the military powers of the world. But most of these UAV’s lack the vertical take-off and landing (VTOL) ability. This report investigates the quadrotor which is an excellent VTOL platform. The main disadvantage that the quadrotor platform possesses is that it suffers from poor performance if compared to airplanes. Quadrotors lack the endurance and the capability to carry heavy payloads. An effort is to be done to investigate the possible application area of use for the quadrotor platform from a military point of view. In order to solve these problems, two COTS (Commercial off the Shelf) quadrotors has been bought and a number of test flights have been performed with them. The results from these tests have been evaluated in MATLAB and a number of simulation models have been created in order to get a clear picture of the quadrotors potential. Rotorcraft such as the quadrotor is affected by the aerodynamic phenomena of induced power, this phenomena is important to understand when designing a control system for the quadrotor and when optimizing its endurance. A number of suggestions for how to improve the quadrotor platform have been proposed such as using ducted propellers, hybrid fuel systems, gyroscopes, and micro technology. A simulation model has been created that predicts the time that a quadrotor of a given size carrying different payloads could maintain itself in hover, this model show that battery based quadrotors are limited in how big they can be made. Much work has been dedicated to the extended sight concept where the quadrotor is intended to be powered by a cable and serve as a pair of extra eyes to an army vehicle such as a tank in an urban environment. Most of the technical difficulties for this concept has been defined and solved, these are mainly electrical difficulties and work on a demonstrator for this concept has been started. All these investigations points towards that the military would benefit from having quadrotors in their arsenal, they could be used for reconnaissance, placing out surveillance equipment and resupplying soldiers behind enemy lines.