Test och utvärdering av framdrivningssystem för drönare avsedd för sjöräddning

Abstract

This thesis has been performed by request of the Swedish Sea Rescue Society during the spring 2020. The object of this thesis is to test and compare different components in the propulsion system of a SAR-drone under development at SSRS. In the future, the drone will support the rescue mission by quickly attend to the scene of distress, loitering the area and sending pictures of the scene to the rescue team preparing them for what situation they will face. With such a function the the quality and safety of the mission will increase considerably. For the drone to be able to perform as many different SAR-missions as possible, a slim, aerodynamic design with energy efficient onboard components is required. In this thesis, 4 propellers, 7 engines and 3 ESCs has been tested to analyze the efficiency of different combinations of these components. All the tests were performed at the voltages 11,1 V and 14,8 V to simulate two types of batteries. The propeller sizes are 12x6,5”, 11x7”, 11x6” och 10x7 and the engines of the makes AXI, EMAX, Hobbywing, Skystars and iFlight XING and the ESCs Jeti, V-Good and Hobbywing. Comparing tests were performed by registering the thrust of the propeller at 50 W electrical power and continuously increasing power feed. Initially a big difference between the ESCs could be seen where Hobbywing where of highest efficiency and Jeti of lowest. The smallest propeller generated the lowest amount of thrust and the biggest the highest amount of thrust in combination with the AXI engine and Hobbywing ESC. The efficiency of the engines varied depending on the adaption to the ESC but the engines from AXI and Hobbywing were distinguished with high results throughout the tests. Overall, the using of lower voltage 11,1 V were more efficient than with 14,8 V, that is caused by voltage-depending losses in the ESC.