Modeling and Control of a Coaxial Monocopter via Moving Mass Actuation

Aerial drone technology plays an increasingly significant role in modern life, with applications ranging from environmental monitoring and infrastructure inspection to delivery services and aerial photography. As the range of use cases continues to expand, there is a growing need to explore innovative drone types and configurations that can offer improved performance, enhanced efficiency, and adaptability to complex environments. Among these, the coaxial monocopter has emerged as a promising alternative to conventional quadrotors, offering aerodynamic efficiency and reduced mechanical complexity. This study presents the structural design, dynamic modeling, simulation, and control development of a novel moving-mass coaxial monocopter. The proposed platform utilizes internal mass displacement to achieve maneuverability, thereby eliminating the need for traditional active stabilization mechanisms. The design prioritizes simplicity and is tailored for long-endurance operation. The systemdynamics are derived using the Lagrangian method to accurately capture the coupled behavior introduced by the moving mass. A dynamic model is formulated to investigate stability conditions, and numerical simulations are conducted to validate the model and assess its nonlinear characteristics. A simple proportional-integral-derivative (PID) control strategy is implemented to address the primary control challenges, demonstrating the system’s ability to achieve stable flight. Comparative analysis with a thrust-vectoring configuration highlights the advantages of the proposed approach, offering a streamlined and effective alternative for aerial mobility.