MAKING locusts watch battle scenes from Star Wars could eventually
help cars steer themselves out of trouble.
Researchers in Britain and Switzerland have already exploited this bizarre
research to build a robot that can dodge approaching objects. They hope the
robot’s neural network program, which mimics part of the locust’s brain, will be
the basis of a collision-avoidance system for cars.
The conventional approach to creating such systems involves using radar or
infrared detectors, and requires very heavy-duty computer processing. Insects,
however, manage to dodge objects despite their poor vision and basic brains.
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In locusts, the key to this ability is a large neuron behind each of their
compound eyes called the lobula giant movement detector. The LGMD is thought to
be partly responsible for triggering the insects’ escape jumps and steering
responses during flight, says Claire Rind, a neurobiologist at the University of
Newcastle.
So copying the behaviour of the LGMD could help create fast and efficient
avoidance systems for vehicles such as cars and planes, Rind says. “The
advantage of using this neuron is that it can discriminate between objects that
are on a collision course and ones that aren’t,” she says.
To build up a picture of how this neuron works, Rind showed a locust images
of rapidly approaching objects while monitoring the neuron’s activity. She chose
scenes from Star Wars, she says, because the film has particularly good
shots of objects—such as Tie fighters—heading for the viewer during
dogfight sequences.
Working with Mark Blanchard and Paul Verschure of the Institute of
Neuroinformatics at the Swiss Federal Institute of Technology in Zurich, Rind
then built a robot with a vision system based on the locust’s. The small
three-wheeled robot has a camera with a resolution of just 20 by 20 pixels,
which closely imitates the locust’s grainy vision.
As in the locust, signals from these makeshift photoreceptors are subjected
to some pre-processing by a neural network—providing some basic “edge
detection”—before they reach the robot’s movement detector, which is
designed to respond in the same way as the LGMD. The researchers found that
their robot avoided objects 91 per cent of the time, even though it had only a
short time to react.
Nigel Clarke, principal engineer at the car company Jaguar’s radar
applications research unit in Coventry, has been keeping a close eye on Rind’s
progress. “We certainly think there’s a great deal of mileage in using
techniques that the brain uses to calculate these things, such as detecting
moving objects in a scene,” he says.
Blanchard believes that traditional approaches to collision
avoidance—such as infrared or laser rangefinders and ultrasonic
reflections—are too easily confused by spurious signals. “Most biological
systems can see,” he says, “so it’s at least one approach that should be
exploited in trying to make machines explore for themselves.”
But Rind says more research is needed before the technology can be exploited
commercially. She now wants to monitor the locusts’ response to natural stimuli,
instead of movies, and work out how the speed of approaching objects affects
behaviour.