Optimum attitude planning of near-space solar powered airship

Abstract

The attitude of Near-space airship including yaw, roll and pitch angle is important to the output performance of airship solar array. The yaw angle of airship can be controlled without affecting airship mission execution in the quasi-zero wind layer of near-space. This paper aims to improve solar energy system of near-space airship by optimizing airship yaw angle. Based on the solar radiation model and solar array energy model, a MATLAB program is established to calculate the output power. For model validation, solar radiation and output power are simulated and compared with experimental results. The optimum yaw angle for a whole year is obtained with optimization model based on genetic algorithm. The effect of airship shape parameters including the slenderness ratio and the ratio of forebody length to total length (L1/L) is elaborated. The results show that the effect of yaw angle on output power is greater at higher latitude than that at lower latitude and the solar array output energy can be remarkable increased after adjusting yaw angle of airship according to the optimization result. Although the optimal yaw angle is different with the change of working date and latitude, the optimum values mainly lie in 0° and 180°. Moreover, the optimal yaw angle is barely changed, when the slenderness ratio and L1/L of airship are greater than 0.3 and 0.25, respectively. The result has great valuable engineering reference in attitude planning of near-space airship and other aerospace vehicle for energy improvement.