Model-based flight path planning and tracking for tethered wings

In this paper we propose a guidance strategy for the flight control of a tethered wing. We control the wing trajectory in a cascaded approach via the velocity vector orientation. In particular, we consider a control-oriented model with an input delay to follow a reference path. To account for the delay we design a predictor and use the predictions to compute a reference for a lower level tracking controller. In a path-planning step we design reference figure-eight paths for the wing to follow. The path design explicitly considers the model parameters used in the tracking controller such that limitations induced by the delay are respected. By estimating the model parameters on-line we enable the adaptation of the tracking controller and also the path-planner to time varying conditions, including the input delay and crucially the line length. We present the derivation of the guidance strategy and demonstrate its performance via simulation results.