Contents I. Introduction
The Monocopter is a platform with a lot of potential for research. One area that needs further exploration is its performance and limits in trajectory tracking. Currently, there has been little development in controlling the Monocopter for this purpose, and the limitations of its flight envelope are largely unknown. In the early stages of Monocopter research, as detailed in [13], [17], [20], [28], [31], a thorough examination was conducted on the dynamics necessary for both hovering and translational flight. Much of this investigation drew inspiration from the dynamics employed by helicopters [18]. Unlike the comprehensive groundwork laid out by [23] for understanding quadcopter dynamics, the original Monocopter dynamics developed by [20] remain incomplete. This is primarily due to its failure to consider deviations in disk precession rates caused by the interactions between the body’s angular momentum and the disk’s torque. Additionally, studying the Monocopter’s dynamics from its annular frame [18] is an uncommon approach, since most research efforts center around the body frame in their analyses. Subsequent attempts were made by [22] to scrutinize the hovering dynamics from a new perspective whilst recent research was done by [5], [6] to investigate the use of attitude control in separating Monocopters for cooperative flight, and [2] for achieving hovering flight with a biomimetic rotating wing that’s passively stable in attitude. Their research highlighted that control schemes significantly influence dynamics, prompting the need to differentiate the craft’s control approach during both translational and rotational motion. In the context of translational motion, their studies predominantly centered around minimum velocity trajectories, limited to a confined region within their flight envelope. For trajectories above the order of 1, [1] made advancements in computing feed-forward terms for rotating micro aerial vehicles, however, their platform’s flight dynamics mimicked that of a quadcopter which enabled minimal penalization in tracking accuracy whenever the body frame encountered precession. With the premise being set, the focus and contribution of this paper is to address the modeling of the Monocopter that would encompass the property of differential flatness for trajectory tracking. This is combined with a cascaded position to attitude controller for a Monocopter platform like the SICARO, which has an extended flight range capability enabling it to fly on either side of its wing in specific rotations [26]. With this approach, nature-inspired Monocopters can achieve better precision in trajectory tracking whilst reducing energy consumption as compared to existing methods. This is crucial for deployment applications such as surveillance and payload deliveries that may equip them with small and limited battery capacities.
