Harnessing the Differential Flatness of Monocopter Dynamics for the Purpose of Trajectory Tracking in a Stable Invertible Coaxial Actuated ROtorcraft (SICARO)

In this paper, the dynamics of an emerging class of rotating nature-inspired micro aerial vehicles known as the Monocopter is proven and shown to be differentially flat. By exploiting this phenomenon, trajectory tracking can now be implemented on Monocopters via feed-forward terms that are computed per the trajectory. To demonstrate this, a Monocopter in the form of a Stable Invertible Coaxial Actuated ROtorcraft (SICARO) is chosen to harness this approach fully. The SICARO is capable of flying with either side of the wing facing up and this feature determines the craft’s direction of rotation about its body Z axis as well. In addition, it has the unique feature of a coaxial motor configuration that allows for a pitching-up moment regardless of the wing side facing up. The feed-forward terms computed are fused into a cascaded nonlinear controller on the craft to ensure its effectiveness in tracking trajectories. Lastly, the flight experiments extend to both sides of the wing to validate this method as being applicable for trajectory tracking for Monocopters such as the SICARO which has an extended range of flying capabilities. SUPPLEMENTARY MATERIAL: Extended flight demonstration of the proposed approach: https://youtu.be/L-e93C53kzM?si=kzKEeshclOOqtlHW Flight demonstration of how the SICARO flies: https://youtu.be/7y2i45iqZhw?si=Xf79UzpBK9hsByME