Locusts Inspire Technology That May Prevent Car Crashes

John Roach
for National Geographic News
August 6, 2004
Locusts are commonly associated with plagues, food shortages, and death. But for a team of European scientists, the grasshopper-like insects are inspiring a technology that may save lives by preventing hundreds of thousands of car crashes.

"Locusts are good at avoiding collisions," said team member Claire Rind, a biologist at the University of Newcastle upon Tyne in England. "We should learn from a species that is good at the task."

The insects migrate in swarms as dense as 80 million adults per square kilometer (0.4 square mile) yet avoid crashing into each other and the mouths of predatory birds.

Jack Ference is an electronics engineer with the U.S. National Highway Traffic Safety Administration in Washington, D.C., which oversees a U.S.-led crash-avoidance initiative. He said approximately 3.6 million cars are damaged each year as a result of rear-ending the car in front of them, swiping another car while changing lanes, or running off the road.

Upward of half of these wrecks could be prevented with effective crash-avoidance technologies, which the automobile industry views as the future of car safety. "We've spent as much as we can to make cars more crashworthy. Now's the time to do something more active," Ference said.

Together with colleagues from the Hungarian Academy of Sciences in Budapest, the National Center of Microelectronics in Seville, Spain, and the Volvo Car Corporation in Göteborg, Sweden, Rind is developing crash-avoidance technology based on locusts' navigational skills.

Crash-Avoidance Course

Locusts, which can consume their own weight in food each day, have a large neuron called the locust giant movement detector (LGMD) located behind their eyes. The LGMD releases bursts of energy whenever a locust is on a collision course with another locust or a predatory bird.

A few years ago Rind and her colleagues studied the activity of the LGMD as locusts watched action scenes from the movie Star Wars. The team found that the LGMD releases more energy when something is coming directly at the locust.

These spikes of energy, called action potentials, prompt the locusts to take evasive action. The entire process from motion detection to reaction takes about 45 milliseconds—or 45 thousandths of a second.

"Locusts, like most insects, can see many more images per second than we do. This means they can react in time to things that are approaching very rapidly and so make their escape before collision," Rind said.

The locusts' ability to see many more images per second than humans gives them a remarkable view of the world. For humans, it would be like watching everything go by in slow motion, Rind added.

And because the insects only detect things that are on a collision course with them, the locusts are ignorant of all other movements. It's a particularly useful trait, as the locusts travel in dense swarms akin to rush hour traffic.

"The [LGMD] system is complemented by the brain of the locust, which provides the necessary experience and knowledge to really react according to the situation," said Jorge Cuadri, a project engineer with Spain's National Center of Microelectronics. Cuadri is helping to develop the circuitry for the locust-inspired crash avoidance technology.

Circuitry Development

Cuadri and his colleagues are responsible for adapting the locust collision-avoidance system to the automotive environment.

Their adapted system is based on a single, integrated step that combines visual optics and electronics. The conventional way of doing this would involve tow steps: First, a camera would capture the image. Second, a digital processor would analyze it.

The two-step approach, which uses radar images, is expensive and currently limited only to luxury cars, Rind said.

"[Our] system, once mass produced, won't be so expensive as to stop it from being applied, and it will also be very quick," she said. "It's meant to cover the collision which is only a few seconds away."

The challenge, according to Cuadri, is building circuits that can function wherever car and driver may go.

"One of the biggest problems we have regarding the electronic implementation is the huge range of illumination conditions under which the chip should be able to see," he said. "Another difficult point is the climatic conditions, since the chip should work from really low temperatures to real hot."

To date, the team has built a locust-inspired, collision-avoiding robot and is currently developing crash-avoidance circuitry for a model car. In a few years Volvo may have a prototype. By the end of the decade cars equipped with the locust-inspired technology could be on the showroom floor.

The system is envisioned as something that would detect approaching danger before a human notices it. The system would sound an alarm so that the driver could take evasive action. "If the situation gets worse, it would apply the brakes, initiate defensive features, such as tensioning of the seatbelts, and arming inside airbags," Rind said.

In the future the system may also deploy external airbags on the front bumpers to protect pedestrians. Initiatives requiring such pedestrian-safety oriented technologies are on the books in Europe and in discussion in the U.S.

According to Ference, consumer adoption of crash-avoidance technologies will depend on how efficient they are at giving out warnings without annoying the driver with excessive false alarms.

"It's very complex," he said. "We have to think through how to warn a driver in an unambiguous way that gets their attention and warns them when they want to be warned and not when they don't, so they are not annoyed by it."

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