Nonlinear control and estimation of a tethered kite in changing wind conditions

A study was conducted to develop a nonlinear feedback controller that stabilized the kite motion using a set of noisy measurements of the system. The study used numerical simulations to demonstrate the effectiveness of the controller for tracking power-generation trajectories. The study found that the loop was closed with the kite using feedback and nonlinear optimal control with a tether dynamic model. The study showed that the controller, combines a nonlinear outer loop, was followed by the system in response to changes in wind speed and direction. The updated reference trajectories were tracked using an inner-loop controller based on the time-varying linearized dynamics. The study found that the control of the kite was achieved under changing wind conditions using filtered measurements in the feedback loop.