Configuring RTK-GPS Architecture for System Redundancy in Multi-Drone Operations

The researches on Real Time Kinematic GPS (RTK-GPS) have been actively conducted to accurately estimate the location of drones, and there were many use cases applied to drones. However, such systems using RTK-GPS do not provide the protection against network instability, failure of the components that make up the RTK-GPS service. In other words, availability is not provided to ensure the stability of the RTK-GPS. In this paper, we propose an architecture enabling redundancy to improve the availability of RTK-GPS system by switching or parallelizing the GPS correction data sources. We also introduce how to propagate the correction messages through the drone network. After evaluating the system on empirical testbed, we validated that the correction messages propagated without delay, the message source was switched or multiplexed among several message sources through the proposed system when the network was unstable, and the switching time was short enough not to affect our propagation system. Consequently, we have confirmed availability through the proposed architecture of RTK-GPS redundancy.