A New Overactuated Multirotor: Prototype Design, Dynamics Modeling, and Control
Yipeng Yang, Xinghu Yu, Zhan Li, Michael Basin
Abstract
Multirotors have been extensively used due to their simple structure and flexible flight capabilities. However, traditional coplanar multirotors are underactuated in such a way that their 3-degree-of-freedom (DoF) position and 3-DoF attitude cannot be controlled simultaneously. This article proposes a new overactuated flight platform using biaxial-tilt actuation unit (BTAU), called <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Quad3DV</i> , with capability of antidisturbance 6-DoF trajectory tracking. The structure of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Quad3DV</i> is simpler than other published multirotors with BTAUs, and can hover at <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex-math notation="LaTeX">$90^\circ$</tex-math></inline-formula> pitch with higher flight efficiency. First, the 6-DoF multibody dynamic model of the whole system is given considering variable inertia parameters, gyroscopic effects of the BTAU, and coupling effects of translational and rotational motions. Second, based on this model, an antidisturbance Lyapunov stable 6-DoF trajectory tracking controller is designed. Extended state observer is adopted to estimate the unmodeled error and external disturbances. Third, an admissible-wrench-space-optimal geometric control allocation method is proposed, which fully exploits the controllability and attitude accessibility of <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Quad3DV</i> . Fourth, simulations were carried out in the high fidelity dynamics simulation software to compare with other controllers. Finally, flight experiments were conducted to verify the effectiveness of the whole system.