Adaptive Control Allocation for A New Bi-Copter With Center of Gravity Uncertainty

Abstract

A pair of vectored thrusts grants bi-copters greater power efficiency than quadrotors but also makes them more susceptible to the uncertain center of gravity, which alters the steady state attitude and challenges the control. In this letter, we leveraged this feature by designing a new bi-copter incorporating a middle servo, converting its natural drawback into a functional advantage. Such an arrangement allows the bi-copter to actively change its steady state attitude, enabling it to navigate through narrow gaps in different orientations. Additionally, compared to conventional multi-rotors, it has a superior capability to handle eccentric payloads. The adaptive control allocation is designed to handle the steady state variation caused by the uncertain center of gravity. Flight experiments are conducted to demonstrate the effectiveness of the proposed bi-copter together with the control scheme.