Cooperation through self-assembly in multi-robot systems

Abstract

This article illustrates the methods and results of two sets of experiments in which a group of mobile robots, called s-bots, are required to physically connect to each other, that is, to self-assemble, to cope with environmental conditions that prevent them from carrying out their task individually. The first set of experiments is a pioneering study on the utility of self-assembling robots to address relatively complex scenarios, such as cooperative object transport. The results of our work suggest that the s-bots possess hardware characteristics which facilitate the design of control mechanisms for autonomous self-assembly. The control architecture we developed proved particularly successful in guiding the robots engaged in the cooperative transport task. However, the results also showed that some features of the robots' controllers had a disruptive effect on their performances. The second set of experiments is an attempt to enhance the adaptiveness of our multi-robot system. In particular, we aim to synthesise an integrated (i.e., not-modular) decisionmaking mechanism which allows the s-bot to autonomously decide whether or not environmental contingencies require self-assembly. The results show that it is possible to synthesize, by using evolutionary computation techniques, artificial neural networks that integrate both the mechanisms for sensory-motor coordination and for decision making required by the robots in the context of self-assembly.

Performance benefits of self-assembly in a swarm-bot

“…Initially, we consider the simple benefits of scale conferred by selfassembly: some tasks can be carried out more effectively if the robots act as a larger connected entity [10]. For example, a larger robotic entity might have increased stability for rough terrain navigation [6] or increased strength for object transportation [15].…”

Control of one-dimensional guided formations using coarsely quantized information

“…In intelligent highway systems, the guiding commands are expected to be simple and formatted as short digital messages to scale with the number of vehicles and also to avoid conflict with the automatic driver assistance systems installed within the vehicles. Similar guided formation control problems also arise when navigating mobile robots or docking autonomous vehicles [4].…”

An extensive review of research in swarm robotics

“…Modular self-reconfigurable robotic systems can be generally classified into several architectural groups by the geometric arrangement of their units [44]. Lattice architectures [45][46] have units that are arranged and connected in some regular, three-dimensional pattern, such as a simple cubic or hexagonal grid.…”