Lattice Formation in Mobile Autonomous Sensor Arrays

Abstract

The purpose of this work is to enable an array of mobile sensors to autonomously arrange themselves into a regularly spaced lattice formation such that they may collectively be used as an effective phased-array sensor. Existing approaches to this problem encounter issues with local minima which allow the formation of lattice patterns that are locally regular but have discontinuities or defects that would be undesirable in a narrow-band beamforming application. By exploiting a common reference orientation, such as might be obtained from a magnetic compass, we have been able to create control laws that operate on orthogonal axes and thereby minimize the occurrence of local minima. The result is that we can now form lattice patterns with greater uniformity over extended distances, with significantly less energy or movement per robot. Despite the need for a shared directional reference, our methods are also robust to significant error in the reference readings.