Model-Free Control-Based Trajectory Tracking Control of a Tail-Sitter UAV in Hovering Mode

This article presents a novel model-free control (MFC)-based controller for achieving accurate trajectory tracking control of a tail-sitter unmanned aerial vehicle (UAV) in hovering mode. The challenges associated with strong coupling, parametric uncertainties, and wind disturbances are addressed. To enhance robustness and accuracy, the controller incorporates interconnection and damping assignment passivity-based control (IDA-PBC) technology to design the auxiliary input. The reshaping characteristics of IDA-PBC significantly improve the control performance. In addition, a compensation term is introduced to account for neglected dynamics and time-varying external disturbances, thereby increasing the control robustness level. This online compensation capability, derived from the MFC principle, distinguishes between modeled system dynamics and unmodeled parts. In addition, a novel data-driven approach is suggested for tuning control parameters of the ultra-local model in MFC, aiming to enhance trajectory tracking capabilities. To assess the controller’s performance, both hardware-in-the-loop (HIL) simulations and real flight tests are carried out. The obtained results showcase the exceptional precision and robustness of the proposed controller, even under external disturbances and uncertainties in the model.