A least squares-based heading direction estimation for a robot swarm with only ranging capability

For a wirelessly networked robot swarm, we have developed a method of generating a set of common coordinates with only ranging capability in the wireless communication protocol being used to network robots and have evaluated its performance by computer simulations and experiments. The proposed method essentially gives a robot swarm an initial step to notify each robot of its own heading direction in a set of generated coordinates, before the swarm tries to accomplish a given unified task. However, the estimated heading direction for each robot is not accurate enough to be able to control the motion of the swarm as a group, so a method for improving the accuracy of the heading direction is necessary after the initial step. In this paper, we propose a least squares (LS)-based method of improving the initially estimated heading direction for each robot, which is applicable during a series of the motions of the swarm. We evaluate the performance of the proposed method by computer simulations and experiments.