Anti-collision Sensing for Unmanned Aerial Vehicle in Planetarium Using Circular RFID Array on Spherical Balloon

This study presented a new anti-collision sensing system based on a circular array configuration of linear shaped RFID tags attaching on a spherical balloon. This system is applied on an unmanned aerial vehicle (UAV) which moves around inside a planetarium for dome screen inspection, to sense whether the UAV is approaching to the dome screen and in what direction. The benefit of the circular configuration for the RFID array, in contrast to the traditional planar configuration, the sensing system can detect the proximity surrounding the UAV as well as the distance to the ceiling. The sensing principle is based on the signal strength variation of the antenna of the RFID tags when a metal plate is at the proximity. From the measurement results, it is verified that the signal strength of the tags become larger when a metal plate is closed and the range of variation is about 4 to 8 dB, thus confirming the effectiveness of the proposed anti-collision sensing using circular RFID array.