Efficient localization of multiple robots in a wide space

In this paper, the multiple block localization method for multiple robots in a wide space using iGS system is proposed. The iGS system is developed for the indoor global localization using ultrasonic and RF sensors. This method provides the high accuracy solution using only low price sensors. To measure the distance between a mobile robot and a beacon, the tag on the mobile robot triggers one of the beacons in order to send out the ultrasonic signal and measures the transmission time from the beacon to the mobile robot. The more the number of robots is, the longer the localization sampling time is. Note that only one robot can localize its position during each of the sampling time intervals. This is a severe constraint for the localization of multiple robots in a wide space. This paper proposes an efficient localization algorithm for multiple robots in a wide space which can be divided into multi blocks. For a given block, a master beacon is designated to synchronize robots. Accessing the synchronization signal, each beacon in the selected group sends out an ultrasonic signal. When the robots in the block receive the ultrasonic signal, they can calculate their own locations based on the distances to the beacons, which are obtained by the multiplication of transmission time and velocity of the ultrasonic signal. The efficiency of the algorithm is verified through the real experiments.