Robot self-localization in ultra-wideband large scale multi-node setups

The large bandwidth of the UWB (UltraWideband) communication systems, makes it ideal for time of travel localization techniques such as ToA (Time of Arrival) and TDoA (Time Difference of Arrival). The techniques based on ToA demand high rate of network traffic which are not suitable for multi-node setups. The TDoA however, addresses this issue, making it possible to have several anchors and nodes at the same time. This paper discusses the two possible setup structures of TDoA technique and provides a comparison of them. The focus of this paper is on the forward TDoA method, which can effectively be used for an unlimited number of robots in the setup with minimum network traffic and high rate of position data updates. A method has been proposed for synchronization of the clocks in anchors based on the Kalman Filter. The positioning algorithm is implemented using the Extended Kalman Filter. The results prove good performance of the method for positioning of large number of robots with accepted level of accuracy and computational effort.