Bi-directional pheromone communication between robots

Abstract

SUMMARY This paper describes a project that aims to demonstrate two-way communication between robots using chemical signals. The project is part of a wider investigation examining the potential advantages and drawbacks of implementing pheromone signalling between robots. It is well known that all kinds of biological creatures use chemicals as a means of attracting, repelling, controlling, guiding and informing their fellow creatures. This very wide range of effective biological forms of chemical communication is the inspiration to look at potential robotic applications. In previous work involving the use of physical chemical signals in robotics the case of one robot releasing or depositing a chemical for other robots (or the same robot) to detect and act upon has been addressed. This project moves a step forward to investigate a group of robots where each group member emits and detects pheromone chemicals. The example task addressed in the project is to use chemical signalling to help a collection of robots to assess group size. Bacteria provide a model for this kind of chemical communication. By monitoring chemical concentration bacteria can assess group size and hence modify their behaviour as appropriate. Although not intending to model bacterial quorum sensing in detail this behaviour provides inspiration for our demonstration of bi-directional communication. This paper provides details of the implementation of quorum sensing in a group of robots. The robots used in the project, their control algorithms and experimental results are presented. Both beneficial aspects and the pitfalls of pheromone communication in robotic systems are also discussed.