'Manchester Computer Scientists working to help save lives take inspiration from 'mole'
Date: 2nd June 2006
In 1999 a gigantic earthquake struck Taipei, Taiwan, collapsing tower blocks and killing more than 400 people. Rescue teams were left to dig through the rubble and try to locate survivors. EPSRC-supported research into a digging robot could help in future disasters.
Robot ‘Mole’
Scenario: Somewhere within a collapsed building people are trapped under rubble prone to secondary collapse.
EPSRC Project: To develop a robotic excavator that can shift heavy debris aside and crawl through voids in the rubble to locate survivors. A prototype is currently being built which uses a digging style inspired by that most efficient and careful excavator the European mole. This small robot also has to be energy efficient and expendable.
Emergencies come in many shapes and sizes – from accidents to large-scale disasters such as earthquakes or bombings. Yet whatever the scenario you can bet that scientists and engineers are working to help save lives. In the first part of this special report Newsline looks at how research can help the emergency services mount a rescue.
Reaching survivors trapped in buildings that have collapsed due to natural disaster or terrorist attack is no easy task. Not only do those involved know that every minute diminishes the chances of finding people alive but they often have no idea where any survivors might be. Usually the only option is to dig, listen and hope. Now researchers at the University of Manchester plan to give rescue teams a new option; sending in a robot that can burrow through the rubble to find where people are trapped.
Any Urban Search And Rescue (USAR) robot has to cope with an extremely hazardous working environment. Collapsed buildings feature many small spaces or ‘voids’ which offer potential passageways for a robot to crawl along. Yet these passageways tend to be choked with debris and there is always the danger of secondary collapse triggered by the robot’s movements.
“One of the major limitations of existing USAR robotics is the lack of manipulation capability that we see as vital to be able to move through and between void spaces” explains Dr Rob Richardson of the Manchester Robotics group, “but the energy and torque required to manipulate debris is considerable and any force has to be exerted efficiently and in a way that avoids secondary collapse.”
Developing a robot which can move debris of a similar size to itself is a considerable challenge as all current mechanical excavators only move material a fraction of their size and weight.
So when they came to design their robot the Manchester researchers turned to one of Nature’s most accomplished excavators, the common European mole, for inspiration.
“We investigated a variety of animals with different digging techniques,” says Dr Richardson, “amongst the most specialised diggers we found that the European mole has evolved to be able to produce the greatest amount of digging force for its size.”
This force-to-size ratio is important because any robot will have to be small enough to fit into voids but still able to deliver sufficient force to shift debris out of the way.
The researchers took particular inspiration from the mole’s movement ranges, bone structure and muscle locations as this would enable them to recreate its highly efficient digging action.
“In order to achieve this motion we first defined the trajectory that the manipulators should follow.
The shape of this trajectory had to alter depending on the position of the robot and the forces being exerted: this allows it to respond to unmoveable debris and to avoid its manipulators pushing debris into its path as they move forward,” research associate Dr Robin Scott tells us. So far the researchers have made vital strides in understanding debris fields and what’s required to move through them.
These studies helped them come up with and then simulate a range of design concepts to see which would meet their exacting torque and efficiency targets, Dr Richardson adds: “Our simulations have now led us to a novel and efficient
mechanism that is able to reproduce the desired elliptical trajectory. Manufacture of this prototype is about to begin.”
Written by Pete Wilton
Find out more about the School's Artificial Intelligence Group
For further information:
For more on the USAR robot e-mail Dr Rob Richardson at rob@cs.man.ac.uk
More articles about how researchers are applying science to some combat real world problems are available in EPSRC’s Newsline magazine: http://www.epsrc.ac.uk/CMSWeb/Downloads/Publications/Newsline/NewslineIssue36.pdf