The work paves the way, says the University, for robot 'swarms' to be used in industries such as agriculture where precision farming methods could benefit from the use of many very simple and cheap robots.
A group of 40 robots were programmed to perform the clustering task and the researchers have shown, using computer simulations, that this could be expanded to include thousands of robots.
According to the university, each robot uses just one sensor that tells it whether or not they can 'see' another robot in front of them. Based on whether or not they can see another robot, they will either rotate on the spot, or move around in a circle until they can see one.
In this way they are able to gradually form and maintain a cluster formation. The system's ingenuity lies in its simplicity.
The robots have no memory, do not need to perform any calculations and require only very little information about the environment. This apparently surmounts the problem of robotic swarms requiring complex programming, making it difficult to miniaturise the individual robots.
"What we have shown is that robots do not need to compute to solve problems like that of gathering into a single cluster, and the same could be true for swarming behaviours that we find in nature, such as in bacteria, fish, or mammals," said Roderich Gross, of SCentRo.
"This means we are able to 'scale up' these swarms, to use thousands of robots that could then be programmed to perform tasks. In a real world scenario, this could involve monitoring the levels of pollution in the environment; we could also see them being used to perform tasks in areas where it would be hazardous for humans to go. Because they are so simple, we could also imagine these robots being used at the micron-scale, for example in healthcare technologies, where they could travel through the human vascular network to offer diagnosis or treatment in a non-invasive way."
The university says the researchers are now focusing on programming the robots to accomplish simple tasks by interacting with other objects, for example by moving them around or by sorting them into groups.
The research work is published today in the International Journal of Robotics Research.
It was supported by the Strategic Educational Pathways Scholarship (Malta), the European Union - European Social Fund (ESF), under Operational Programme II - Cohesion Policy 2007-2013, "Empowering People for More Jobs and a Better Quality of Life", and the Marie Curie European Reintegration Grant within the 7th European Community Framework Programme.