AEROBULL: A Center-of-Mass displacing aerial vehicle enabling efficient high-force interaction

Aerial manipulators are increasingly used in contact-based industrial applications, where tasks like drilling and pushing require platforms to exert significant forces in multiple directions. To enhance force generation capabilities, various approaches, such as thrust vectoring and perching, have been explored. In this article, we introduce a novel approach by investigating the impact of varied CoM (Center of Mass) locations on an aerial manipulation system’s force exertion. Our proposed platform-AEROBULL features a design with a dynamically displacing CoM, enabling a smooth transition between free flight and high-force interactions supported by tilting back rotors. We provide a detailed study of the aerial platform’s overall system design, hardware integration of the developed physical prototype, and software architecture of the proposed control algorithm. Physical experiments were conducted to validate the control design and explore the force generation capability of the designed platform via a pushing task. With a total mass of $3.12kg$, the aerial vehicle exerted a maximum pushing force of above $28N$ being almost equal to its gravity force. Furthermore, the experiments illustrated the benefits of having displaced CoM by benchmarking with a fixed CoM configuration. Additionally, we introduce a quantitative factor to compare the force exertion capabilities of our system with existing platforms, highlighting the advantages of our approach.