Receding Horizon Trajectory Generation of Stratospheric Airship in Low-Altitude Return Phase

The contribution of this paper is the proposal of a new receding horizon trajectory generation method for stratospheric airships' return phase. Since the energy consumption, wind field and path constraints are restrictions during the return phase of airships at low altitude, it is crucial to develop novel trajectory optimization methods to ensure that the airship returns to the landing site. In this article, optimization objects and conditions of the return trajectory were constructed, considering the energy consumption and wind field. Then, a modified interior point method (MIP) was used to transform the inequality constraint, which is a simple and adaptable method used to improve the solving efficiency on the basis of a modified multiple shooting method (MMS). In addition, an adaptive gradient descent regulator was improved to reduce the influence on the optimization result due to different selections of the initial search point, and the convergence was made faster and more stable. Finally, considering the performance and path constraints of the airship, the effectiveness of the scheme was verified by numerical experiments under wind effects and a comparison of different methods.