Underwater rescue robots designed by Sheffield University

Their study has involved a set of robotic modules that, similar to Lego, can be assembled into robots of arbitrary shape.

This allows robots to be customised to meet the changing demands of their task.

Sheffield University researchers are set to reveal their findings this week at the International Conference on Robotics and Automation (ICRA 2016) - the largest gathering in robotics, being held this year in Stockholm, Sweden.

Each module is a cube and has four micro pumps which allow it to move around independently in the water. When modules are joined together, they can draw in fluid from each other, as well as the environment.

The moving of fluid through the network of modules causes the robot to move. The more modules in the network, the more precisely the robot moves, and the better it copes with faults. This new concept is called Modular Hydraulic Propulsion (MHP). The researchers set the robot a task – to detect and move towards a light source. The robots can solve this task reliably without having a central brain. Each module makes its own decisions independently, and only needs a single byte of sensor information to do so.

Dr Roderich Gross, from the Department of Automatic Control and Systems Engineering, who is leading the team, said: “One of the challenges in robotics is to make robots small enough so that they can travel through confined spaces that are otherwise inaccessible. Shrinking robots down, potentially to sub-millimetre scale, puts severe constraints on the hardware and therefore how much information these robots can process.

The university said MHP could offer new solutions to problems requiring “reconfigurable systems” to move precisely in confined spaces, such as the inspection of underground water pipes. In the future, miniaturised versions of MHP robots may even enter the vascular network to monitor the health of patients or deliver drugs in a targeted manner.

Matthew Doyle, a PhD student from the Department of Automatic Control and Systems Engineering who has been working on the project, said: “One potential use for a robot like this is during search and rescue operations in an underwater environment. You may not know the situation in advance, and the robot will have to adapt to whatever it faces.

“The modules could split up and search for survivors more quickly and recombine to lift a heavy object and open up a passageway.

“This type of robot could also be used by utility companies wanting to deal with blockages or faults in pipes that are difficult and expensive to access from the surface.”

The research was funded by an Engineering Physical Sciences Research Council grant. Scientists are now hoping for additional funding to develop the research further and look at how smaller versions of the modules could travel through smaller spaces and solve complex problems.