Optimization of Thrust-Augmented Dynamic Soaring

Dynamic soaring is a non-powered flight mode that enables to fly at no cost by gaining energy from a horizontal shear wind. This is not possible if the shear wind strength is too low. Engine thrust is introduced as a means to augment dynamic soaring in shear winds with insufficient strength. Appropriate models of the vehicle dynamics and the shear wind are developed, and an optimization method is used to construct results on optimal thrust-augmented dynamic soaring. The minimum energy required from the propulsion system is determined for the entire region of insufficient shear wind strength down to zero wind. Solutions of the characteristics of the motion including states and controls are presented. Furthermore, it is shown what a control simplification in terms of an optimal constant power setting as an ease of control yields for the energy required from the propulsion system.