Önen, Anıl Sami
This study addresses the control problem of an airborne wind energy aircraft generating power on the ground. The proposed control tracks a pre-defined trajectory in the power generation phase. The reference attitude information is computed by the trajectory tracking controller such that the aircraft carries out a coordinated turn and maintains a proper pitch attitude to generate the necessary lift to pull the winch. A novel quaternion-based nonlinear attitude controller is designed, utilizing the attitude commands generated by the tracking controller. These commands are in terms of to-go quaternions to utilize a nonlinear attitude controller previously developed for quadrotor flight control as well as solar sail attitude control. However, the approach is extended to fixed-wing airborne wind energy aircraft with aerodynamic nonlinearities. In addition to the six degrees of freedom mathematical model of the aircraft, the winch, an important part of the energy generation system on the ground, is also modeled. Besides the power generation phase, the rewind phase, triggered when the maximum tether length is achieved, is also considered. The success of the developed controller is demonstrated through several nonlinear simulation-based flight tests. The generated power is compared with the theoretical maximum value and other sources from the literature.
Citation Formats
A. S. Önen, “MODELING AND CONTROLLER DESIGN OF AN AIRBORNE WIND ENERGY SYSTEM,” Ph.D. - Doctoral Program, Middle East Technical University, 2024.