무인해양드론의 자율 비행 비선형 제어 및 경로 추종에 관한 연구

다국어 초록 (Multilingual Abstract)

Drones have been widely used in the marine sector to deliver relief supplies, detect fish on fishing vessels, inspect wind turbine blades, observe large marine creatures, and conduct search-and-rescue operations. This paper focuses on the L1 guidance logic for an Unmanned Aerial Vehicle （UAV）, which is vulnerable to the wind disturbances. L1 guidance law has two distinctive features: precise trajectory tracking abilities and tight maneuvers. Notably, this logic exhibits superior performance on the curved path, thanks to the anticipatory acceleration commands in a circular path. The experiments demonstrate the effectiveness of the algorithm. In order to apply to the ultimate mission in the marine environment, such as delivering the emergency equipment to the hatch cover of a dry bulk carrier at the wharf, as well as to the person in distress at sea. The UAV should encounter the complicated obstacles, such as structures on both the ship and the harf. The berthed ship often varies the vertical freeboard of the upper deck according to the cargo work and daily tides. Thus, autonomous flight capabilities of UAVs, including landing accuracy and altitude adaptation, play a crucial role in marine applications. The concepts of guidance law, control basis, and recursive estimators are introduced. Numerical simulation of sliding mode control with trajectory tracking was illustrated. Mathematical models of UAVs were separated based on a series of control theories. The dynamic motion equations are adopted by the Lagrange–Euler formalism or simplified equations to comply with the real-time constraints of the embedded control loop. Then, the two representative models are made to experiment with autonomous flights. Hexacopters and quadrotors are widely used by UAV users. The Pixhawk 2 and Mission Planner were employed in the experiments. The two UAVs performed well in the tracking, driving, vibration, and hovering tests. For example, the vibrations in the X-, Y-, and Z-axes directions were less than 30 m/s/s, particularly those in the X- and Y-axes, which were less than 10 m/s/s. Three altitudes （barometer, EKF, and reference） are matched during the ascent and descent actions. After 126 sorties of two UAVs, it can be concluded that the hexacopter's landing accuracy performance is limited, whereas the quadrotor shows improvement in reducing the landing accuracy to below 10 cm. Then, various autonomous flight missions were carried out. The quantitative results and graphical illustrations were presented. The landing accuracy and bias error are two of the interesting topics from the experiment. A maritime UAV is investigated via an autonomous mission on the breakwater and the fishing boat. A maritime UAV was investigated in an autonomous mission on the breakwater and the fishing boat. Even though the experiment on the fishing boat required big challenges, the hexacopter overcame the limitations of ground tests of UAVs. The tests demonstrated several requirements for the mission in the maritime environment, such as long-distance flight, precise trajectory-tracking accuracy under wind disturbances, safe take-off and landing on an unstable fishing boat,
continuous transmission and reception, vertical ascent and descent in autonomous flight, etc