Landing Simulations of a Solar-Powered High-Altitude Platform with Skid-Type Landing Gear in the Presence of Lateral Wind Disturbances

Abstract

A so-called High-Altitude Platform (HAP) is designed for flight at very high altitudes and for a prolonged period. However, flight at low altitudes, especially in the presence of atmospheric perturbations, is challenging. Therefore, thorough investigations of the aircraft’s landing capabilities and the associated limiting wind conditions are crucial for reducing the risk of a loss of the aircraft during landing. This Master’s Thesis deals with landing simulations in the presence of lateral wind of different types. For this purpose, a model for lateral friction forces of a skid was developed and a lateral controller, based on THCS and a guidance block was implemented. Subsequently, several landings in the presence of lateral constant wind, wind shear and gusts with additional continuous turbulence were simulated using the controller mentioned above and the limiting cases were determined. The simulation process is evaluated through different studies: a parameter evaluation, a sensitivity analysis, a limiting cases identification and a batch evaluation process, to also include a statistical evaluation of the vehicle’s responses. The results of the batch simulation show that the gust disturbances are not very critical, while the wind shear is quite effective in most cases. Additionally, the height of encounter of the disturbances, alongside with the bank angle of the vehicle during the touchdown is crucial with respect to the success of a landing.