Adaptive distributed fetching and retrieval of goods by a swarm-bot

Abstract

Swarm robotics is a rising paradigm which aims at designing new robot artifacts by extracting engineering guidelines from Nature. The work presented here shows the use of a particular swarm of robots called swarm-bot for carrying out distributed missions of fetching and retrieval of objects. To solve this task, a high level description plan defined in terms of behaviors is synthesized. A mission is divided in four different stages: searching for a target, calling for a swarm to aggregate as soon as one is found, jointly fetching it, and jointly retrieving it back. All robots used (s-bots) are assumed to know the same set of behaviors as well as the same behavioral plan for carrying out the task. Units are kept purely reactive, thus they do not keep any memory of their previous history. This allows to withstand changes in a highly dynamic environment. Coordination is achieved asynchronously by using light signals, whereas cooperation for the actual transportation is realized by using a force sensor located between the turret and the tracks of each s-bot. A swarm-bot, which is formed by a group of s-bots physically connected to their target, is capable of behaving during its homeward motion as if it were a single entity. Experiments show the high level of adaptability and resilience of a swarm-bot with respect to occasional possible failures of its members