Hormone-based control for self-reconfigurable robots

Abstract

Self-reconfigurable or metamorphic robots can change their individual and collective shape and size to meet operational demands. Since these robots are constructed from a set of autonomous and connectable modules (or agents), controlling them is a challenging task. The difficulties stem from the facts that all locomotion, perception, and decision making must be distributed among a network of modules, that this network has a dynamic topology, that each individual module has only limited resources, and that the coordination between modules is highly complex and diverse. To meet these challenges, this paper presents a distributed control mechanism inspired by the concept of hormones in biological systems. We view hormones as special messages that can trigger different actions in different modules, and we exploit such properties to coordinate motions and perform reconfiguration in the context of limited communications and dynamic network topologies. The paper develops a primitive theory of hormone-based control, reports the experimental results of applying such a control mechanism to our CONRO metamorphic robots, and discusses the generality of the approach for a larger class of distributed autonomous systems.