SpICED: Design and Control of a Safe Spherical Blimp using Coandă Effect

This paper presents the Spherical Indoor Coandă Effect Drone (SpICED), a safe spherical blimp design propelled by closed impellers utilizing the Coandă effect. Unlike multicopter or conventional propeller blimp, the closed impellers reduce safety risks to surrounding people and objects, allowing SpICED to be operated in close proximity with humans and opening up possibility of novel human-drone interactions. Capitalizing on Coandă effect, the design implements a symmetrical impeller which uniquely allows for bi-directional torque control in the propulsion unit. Different configurations of the arrangement and quantity of propulsion units are explored. The strengths and weaknesses of such configurations are evaluated through dynamical analysis and simulations in 6DOF space. PID controllers are combined with a special control mixing due to the unique dynamics of the propulsion units to achieve position control in all three axes and azimuth control. A physical prototype with a selected Propulsion Unit configuration was then constructed to experimentally validate the dynamic behavior and controls in a motion-captured environment.