Autonomous Landing of a Multirotor UAV on a Platform in Motion
Abstract
Multirotor Unmanned Aerial Vehicles (UAVs) high maneuverability and their capabilityto hover, makes them an extensively used platform in many fields of applications.However, their limitations in flight time challenge the ambition of using multirotorUAVs in fully autonomous operations. By introducing ground or maritime vehicles fordeployment and recovery of the UAVs, or even serve as a service platform performingautomatic battery replacement, it is possible to perform autonomous operations withmultirotor UAVs beyond todays limitations in regards range and duration. To achieve aseamless synergy between the UAVs and the vehicle including a landing pad, requiresthe UAV to be able to perform autonomous landing on the landing pad wile it is inmotion.
This thesis addresses autonomous landing of a multirotor UAV on a vehicle inmotion by using traditional navigation sensors in combination with a camera basedmeasurement system. The camera based measurements and the traditional navigationmeasurements are processed in a Kalman filter developed in this assignment whichperforms sensor fusion, estimates navigation states as well as calculating the sensorbiases. Moreover, two different guidance methods are compared, and a state machinegenerating flight paths and adjusting controller gains are developed.
The camera based measurement system, the state estimator and the controllerare all implemented on the UAV and physical tests have been conducted in real time.Results from the test show that the UAV is, in a robust manner, able to locate, track andprecisely land on a static landing pad. Unfortunately, there was no time to conduct final tests on landing pad in motion. However, results from simulations and the stateestimator indicates that the system is able to carry out autonomous landing on alanding pads in motion.