It sounds like classic sci-fi: Robots, linked by a common network, roam the land. When one unit discovers something, they all know it instantly. They use artificial intelligence to carry out their mission.
Soon, such marching orders will be real, carried out by robot groups known as "swarms" or "hives." For example:
• Last month, South Korea's Defense Ministry announced that it was planning to spend up to $1.9 billion to deploy robots along its border with North Korea. The robots would be used mainly for surveillance, although some could be armed. The effort might allow South Korea to remove some of its troops from along the 150-mile-long demilitarized zone (DMZ), one of the most heavily guarded borders in the world, a defense ministry representative told the Associated Press.
• iRobot, a Burlington, Mass., company that makes military robots along with its popular domestic robot, the Roomba vacuum cleaner, operates perhaps the largest robot swarm in the world. About 100 experimental units operate as a team and have taught at least one important lesson: Real-life robots need to be reminded to recharge themselves. That's led to just such a feature on the Roomba, which now returns to its charging base when its battery fades.
• The United States Army is developing a Future Combat System (FCS) that includes a close network of troops and ground and aerial unmanned robots. The robots would communicate with one another and coordinate their activities based on the mission assigned to them.
"We're very interested" in hive or "swarm" technology, said Dennis Muilenburg, FCS program manager at Boeing, which is being paid $21 billion by the Army to oversee hundreds of contractors working on the FCS program.
The FCS family of ground and aerial robots now under development would include a 25-pound "flying fan" that could be carried in a soldier's backpack, Mr. Muilenburg explained at a robotics conference in Cambridge, Mass., last week. When launched, it would survey the battlefield by hovering overhead or perching on a rooftop. A combat unit of the near future, he said, might consist of 3,000 soldiers, 900 vehicles, and "hundreds of robots" - some of them armed - all closely networked.
The US military will deploy networked robots "within five years," predicts Helen Greiner, cofounder and chairman of iRobot.
Frontline Robotics, in Ottawa, is working with a South Korean firm, DoDAAM Systems Ltd., in a bid to supply robots for the DMZ defense project. The Canadian company plans to offer a line of security robots that possess a significant level of individual autonomy and "hive" intelligence, says Richard Lepack, president and chief executive officer of Frontline, which merged last week with White Box Robotics in Pittsburgh.
In a test last month, two of the company's robots were able to decide for themselves which should enter a narrow passageway first. That's something that may be easy for people, he says, but has been hard for robots to master.
Frontline makes a robotic vehicle that looks like a small Jeep and others that could be cousins of R2D2, one of the robots in the "Star Wars" movies. A proprietary Robot Control System on each unit employs mathematical formulas, or algorithms, that give it some basic movements such as following the leader, avoiding obstacles, or wandering in an area.
The robots also can work as teams, with each having a leader. The teams talk among themselves, and the leaders talk with one another. If a leader is disabled, another robot automatically takes over.
"What one robot sees is shared among all the other team members in real time," Mr. Lepack says. So what Robot A senses is immediately known to Robots B, C, D, and so on.
Robotmakers find inspiration for their programs in nature: the behavior of bee, ant, and wasp colonies, as well as of flocks of birds and schools of fish. Ants, for example, communicate by leaving pheromone trails that other ants can follow to food. Ants also work as teams to distribute their workload, such as finding the most efficient paths for foraging or deciding who will haul bits of leaves back to the nest, without needing any directions from a leader.
In simulations on a computer at Frontline, teams of up to 200,000 robots were shown to be able to coordinate their activities smoothly.
But computer simulations can only do so much, says Ms. Greiner of iRobot. Software can't account for the unexpected, she says. "Whatever you don't put in [to the simulation] will come back and bite you."
The development of "true swarms," thousands or tens of thousands of mobile robots working together, is many years off and "depends on some things that haven't been invented yet," Greiner says, including miniaturization of components and better power sources and sensors.
Military deployment of networked robots will come first, she says. For example, "searching for mines is inherently a parallel task," since you don't want "to put all your eggs in one basket" if a single robot gets blown up. Swarms will be an effective tool for reconnaissance, too. In the foreseeable future, a soldier might take a handful of tiny robots out of his pocket and send them into a building to check it out, she says.
And in an imaginable future, swarms might do much of the routine housework, Greiner says. They'd understand that the dusting robots should come out before the vacuuming robots, which should do their job before the mopping robots. The lawn-mowing robots would scurry around before the raking robots cleaned up.