Design and Control of Soft Unmanned Aerial Vehicle “S-CLOUD”

Short time-of-flight and safety concerns owing to low efficiency and fast rotation of propellers, respectively, are hurdles in the usage of drones. Usually, drones are carrying out missions that distant from the people like aerial photography, measurement, delivery, and surveillance, and, thus, it is not allowed to deploy drones above crowds. In this article, we present a novel soft drone called S-CLOUD that has longer time-of-flight (more than an hour) and higher user safety. It is composed of a torus-shaped envelope made of soft material, filled with Helium gas, and a center flow control unit mounted at the center of the envelope for producing translational (X-, Y-, and Z-axes) and rotational (Z-axis) motions. In this article, the control unit and envelope design are described in detail, and the characteristics of the drone are explained. Moreover, sensor-based feedback control algorithms and their experimental results are described. Finally, applications with S-CLOUD exhibiting its feasibility are also presented.