Jorn H. Baayen

Jorn H. Baayen, Wubbo J. Ockels

A novel tracking paradigm for flying geometric trajectories using tethered kites is presented. It is shown how the differential-geometric notion of turning angle can be used as a one-dimensional representation of the kite trajectory, and how this leads to a single-input single-output (SISO) tracking problem. Based on this principle a Lyapunov-based nonlinear adaptive controller is developed that only needs control derivatives of the kite aerodynamic model. The resulting controller is validated using simulations with a point-mass kite model.

Jorn H. Baayen

A previously published algorithm for trajectory tracking control of tethered wings, i.e. kites, is updated in light of recent experimental evidence. The algorithm is, furthermore, analyzed in the framework of delay differential equations. It is shown how the presence of system delay influences the stability of the control system, and a methodology is derived for gain selection using the Lambert W function. The validity of the methodology is demonstrated with simulation results. The analysis sheds light on previously poorly understood stability problems.