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Control >> Aggregation

Aggregation

Aggregation is of particular interest since it stands as a prerequisite for other forms of cooperation. For instance, in order to assemble into a swarm-bot, s-bots should first be able to aggregate. Therefore, the aggregation ability can be considered as the precondition for other tasks that the swarm-bot is expected to be able to carry out.

At the beginning of our research work, we have focused on the study of aggregation mechanisms by exploiting a behavior-based architectures. The aim of these experiments is to desing the agent's controllers by defining a set of behavioural states and a set of probabilistic transition rules between the states which allow the agents to aggregate. Since at this stage of the project, s-bots were still in the prototyping phase, we carried out our work by mainly using simulated agents. However, some experiments have been run on real robots built with LEGO Mindstorm©.

The work on simulation focused on the study of three shapes of possible aggregates:

Cluster pattern formation
This is the most simple form of aggregate. The behaviours used for it are the base for the all the other aggregations.
Chain pattern formation
The s-bots have to form chains. This structure can be useful, for instance, if pulling of heavy objects is required.
Centre/periphery pattern formation
This structure consider two kinds of s-bots. They have to cluster, but with s-bots of one kind in the centre and the other outside. It can be useful if, for instance, s-bots in the centre can carry heavy objects and those outside have more sophisticated sensors to look for the best path.
The work with real robots focused on chain formation: <>

Chain formation using LEGO Mindstorm©.

The methodological approach mentioned above (i.e., behavior-based approach) have been subsequently abandoned. The work on aggregation has continued by exploiting artifcial neural networks shaped by evolutionary algoithms. In particular, evolution has been used to automatically design the control system of the s-bots for aggregation in a cluster.

This work on scalable aggregation behaviours is described in the following:

Evolving Clustering Formation


Control >> Aggregation

Swarm-bots project started
on October 1,2001
The project terminated
on March 31, 2005.
Last modified:
Sat, 21 Aug 2010 19:46:15 +0200
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