Abstract:

A biologically-inspired swarm of robots with collaboration towards a common mission has a broad range of applications. However, the required dynamic localization among autonomous robots through effective wireless communication for such swarm collaboration, though usually implicitly assumed, has not been properly addressed. In this article, we analyze the use of multiple antennas in the dynamic networking of a swarm of robots. Following the gradient of signal powers along a trajectory, a robot can track the direction of a source robot. With three or more properly placed antennas that sense different phase shifts of the carrier, a robot can localize a source. By lateration,  three collaborative robots can localize a source with known distances to it. Via angulation technique, and three robots can determine their geometric relationship with knowing two angles and one distance between them. On the basis of knowledge of robot locations, beamforming techniques can be employed to receive and transmit a signal towards the desired robot therefore improving power efficiency and prolonging robot lifetime. The techniques can be extended from 2-D to 3-D space for application of wall-climbing robots.

Key words: mobile robots, localization, wireless communication, antennas