Robust Control of Laddermill Wind Energy System

Laddermill flight control problem with closed loop is considered in this paper. Laddermill is an alternative concept for energy production using high altitude kites. The kites have been simulated as rigid bodies and the cable as a thin elastic line. Euler angles and cable speed are controls. Flight control is written as a fusion of two approaches: design of experiments and stochastic optimization. Such combination ensures finding global optimum for any reasonable number of parameters and objectives in a reasonable time while also collecting some information about sensitivities – these two features are much harder to achieve by other means. Robustness has been formulated as an additional objective. We found the system very steady despite big variations of wind velocity. The resulting optimal trajectories can be also used as a first iteration for open loop control algorithms. The methods used can be also employed in wide range of wind energy applications.