THE prospect of disembodied arms creeping around your house like caterpillars
sounds spine-chilling, but a British robotics expert believes this kind of robot
could one day give disabled people more independence around their homes.
Mike Topping of Rehab Robotics in Staffordshire came up with the idea when he
was trying to extend the capabilities of robotic feeding arms that clip onto
wheelchairs. He wants to create a new type of arm that can move about the house
doing jobs that would normally be beyond easy reach of someone in a
wheelchair—such as washing dishes or changing a light bulb.
Each arm, called a Flexibot, is symmetrical lengthwise and has a four-pronged
gripper at each end (see Graphic).
These act both as manipulators and as plug
contacts. Either end of the arm plugs into the power supply via a wall socket.
The arm can move, caterpillar style, by stretching a free end to the next socket
and plugging itself in before pulling its other end out of the wall. The free
end flips round to the next socket, and the arm crawls its way along the wall,
socket by socket.
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It sounds bizarre, but at least one potential user contacted by New
Scientist is interested in the idea. “It would be fantastic,” says
Stephanie O’Connell, who has cerebral palsy and already uses some equipment from
Rehab Robotics. O’Connell uses a fixed-arm system developed by Topping that, she
says, has transformed her life. “It allows me to feed myself,” she says. “I
would be lost without it.” It also helps her with make-up, drawing and playing
games.
With Flexibot, she could extend her repertoire to tasks such as making
herself a cup of tea. But she doesn’t want Flexibot to replace human carers
altogether.
“It’s a good idea,” says Mark Yim, a roboticist at the Xerox Palo Alto
Research Center in California, who envisages the arms doing useful work in
space. They could clamber around the space station or shuttle and spare
astronauts from making potentially dangerous space walks.
In the meantime, Topping also foresees his peripatetic arms finding work in
able-bodied households. At night, the lonesome limbs would be programmed to
creep around and do housework while everyone is asleep.
He reckons most clutter in our homes is found on the floor, so his system
would be designed to keep the floor clear. The robots will also be cheap, he
says, because they won’t need their own power supply or
microprocessor—these would be contained within the walls or supplied by a
PC.
Topping believes Flexibots will have the kind of precision normally
restricted to factory robots working in fixed, predictable environments. Unlike
factory droids, these mobile arms will need sensors that stop them dead if
people or pets get in their way. Topping is studying existing snake-like
robotic locomotion technology
(91av, 4 December 1999, p 9) to
design the most effective motor system.
Perhaps the biggest challenge Topping faces, says Yim, will be making the
arms strong enough. “With snake-like robot arms you quickly run into torque
problems,” he explains. “The longer the arm is, the more difficult it becomes to
hold itself up.”
But Topping doesn’t see the problems as insurmountable. He has filed a patent
on his idea, and hopes to have a working prototype by the end of the year.
The Flexibot idea means having a network of sockets set in the walls and
ceilings, but Topping thinks it’s a small price to pay for the advantages it
brings.