Alexander Kothe
DOI Number: N/A
Conference number: IFASD-2019-074
Aircraft operating as so-called High-Altitude Platform Systems have been proposed to ba a complementary technology to satellites for several years. State-of-the-art HAPS solution have a high-aspect-ratio wing using lightweight construction. In gusty atmosphere, this results in high bending moments and high structural loads, which can lead to overloads. To overcome the shortcomings of such one-wing aircraft, so-called multibody aircraft have been considered to be an alternative. This aircraft technology has been investigated at TU Berlin’s department of flight mechanics, flight control and aerolasticity (project “AlphaLink”) in the last years. This paper presents a summary of the conducted research. After a review looking at the state of the art, the paper describes the design of an exemplary multibody aircraft. The designed reference model is capable of flying 365 days, for 24 hours, between the 40◦ north and south latitude with 450 kg payload operating in high altitudes with solar power only. Further, a complete flight dynamics model is provided and analyzed for aircraft that are mechanically connected at their wingtips. Using the non-linear flight dynamics model, flight controllers are designed to stabilize the plant and provide the aircraft with an eigenstructure similar to conventional aircraft. The resulting inner-control loops yield a multibody aircraft behavior that is similar to the one of a rigid aircraft. Hence, conventional outer-loops can be used for flight guidance.