New insights into autonomous soaring

Abstract

This paper applies computational optimal control to the task of planning optimal trajectories for maximizing altitude gain from thermal updraft columns (‘thermaling’). The Legendre pseudospectral method is applied to a simulated glider over a range of thermal sizes and intensities. Numerical solutions for maximizing altitude gain are compared in performance to standard centered circular orbiting and alternate thermaling strategies suggested by the optimal control results: off-centered circular orbiting, and “figure eights.” Results suggest benefits to utilizing alternatives to centered circular orbiting when encountering small-diameter thermal updrafts.