Published: August 18, 2008 09:59 am            

Ants and swarms

The Civil War’s Robert E. Lee, “It is well that war is so terrible, or we should grow too fond of it.” Research of ants and drones, UAVs — Unmanned Aerial Vehicles — will make a new version of Lee’s quote.

Peter Miller of The National Geographic writes, “… ants marching across my kitchen counter looked so confident, I just figured they had a plan — knew where they were going and what should be done.” A biologist at Stanford University, “Ants aren’t smart, ant colonies are; they can solve problems unthinkable for individual ants, finding the shortest distance to food, allocating workers to different tasks or defending territory.”

This intelligence shows a fundamental fact in nature — swarm intelligence. Ants, bees, a school of fish quickly changing direction.

No one is in charge of an ant colony, none that scientists recognize. Ants communicate by touch and smell, patroller ants tell foragers when to go outside the colony. Biologists say, that’s how swarm intelligence works: simple creatures following simple rules, acting on local information.

The Geographic article, “Inspired by the elegance, computer scientist Marco Dorigo of Brussels used his knowledge of ant behavior to create mathematical procedures to solve complex problems — routing trucks, scheduling airlines or guiding military robots.”

When pigeon flocks on ledges or buildings are disrupted, they’re off in synchronized flight. They have no leader, no pigeon is telling others what to do — each pays close attention to adjacent birds. These rules make another kind of swarm intelligence that has less to do with decisions than with precisely coordinated movements.

Computer graphics researcher Craig Reynolds was curious; in 1980 he created a simple steering program of generic birdlike objects — boids.

In the simulation, each was given three instructions, 1) avoid crowding nearby boids, 2) fly in the average direction of nearby boids, 3) stay close to nearby boids. At the time, Reynolds was seeking ways to depict animals realistically in TV shows and films. “Batman Returns,” 1992, was the first movie to use this approach.

Demonstrating self-organizing models to mimic swarm behavior blazed the trail for robotic engineers. Robots coordinating action as a flock of birds could offer significant advantages over a single robot. Spread over a large area, a group could function as a powerful mobile sensor-net, gathering info about what’s out there. When the fire alarm sounds, instead of humans, machines report happenings at the scene.

The military is acquiring similar capabilities —researchers, January 2004, released a swarm of 66 pint-size robots in an empty building at training center Fort A.P. Hill (Civil War Gen. Ambrose Powell), near Fredericksburg, Va. The mission: find targets in the building. Zipping down hallways, the foot-long robots pivoted on their three-wheels looking as large insects. Eight sensors on each helped avoid collisions with walls and other robots. Each robot, using a small camera, was programmed — if anything pink was sensed, an image was sent to its human supervisor.

Within a half-hour, all six objects had been found. The demonstration was part of an investigation to see if 100 robots could collaborate on a mission.

Cecil Acuff is a Perkins resident.

        

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