Design and implementation of a reliable unmanned aerial system design

• Autor(a) principal: Caria, Tiago Miguel Simão
• Data de Publicação: 2017
• Tipo de documento: Dissertação
• Idioma: eng
• Título da fonte: Repositório Científico de Acesso Aberto de Portugal (Repositórios Cientìficos)
• Texto Completo: http://hdl.handle.net/10071/14823
• topic: Unmanned Aerial Vehicles; Reliable design; Safety mechanics; Engenharia de telecomunicações; Drone; Sensor

With the increase in popularity of the UAV, due to their high accessibility, it becomes even more important that they can be operated in a safe way not only to protect the UAV but also to protect the surroundings and the people. This thesis has the main objective to study ways that allow to increase the security of UAV operations. We start by identifying the failures and their impact and proceed to develop a module that is independent from the principal modules of the UAV. Within this work we opted to focus on the implementation of detection and avoidance of obstacles for the MAV type of UAVs. After making an evaluation of different types of ultrasonic sensors we studied ways to connect them in an array and get a 360º cover of the UAV. Then, we developed three different implementations of an object detection algorithm, with each algorithm being a more complex version of the previous one: First Algorithm – Detection and distance estimation from an object Second Algorithm – Added a false alarm avoidance and direction estimation of the object Third Algorithm – Added the ability to detect more than one object Following the evaluation of those algorithms, we then aimed to develop an interface for the collision module which could send a message to the UAV if an object was detected so that it can change its flight mode and prevent collision. For that the MAVlink protocol was selected since it is compatible with a lot of flight controllers. In the end a final study was made in order to check what was the maximum velocity that an UAV can achieve in order for it to react in time to avoid collision.