Bluetooth is finally taking off. Literally. A small robotic blimp floats gently through the Autonomous Systems Laboratory at the Swiss Federal Institute of Technology, wirelessly interacting with a desktop computer to literally evolve its own navigation software without human intervention. What the blimp sees via its onboard sensors is Bluetoothed to the PC for processing. The artificially evolved "brains" are then transmitted back to the mylar blimp so it can intelligently fly through its environment, improving with each run.

While Bluetooth has been slow to catch on for mainstream applications, engineers in many research labs and garages around the world are leveraging the wireless technology for future generations of small mobile robots and "self-deploying" sensor networks.

"Until recently, Bluetooth has been a bit confusing for consumers," says Bryan Hall, a professional Bluetooth engineer at A7 Engineering and robotics hobbyist. "In the laboratory though, people are more willing to put up with tech warts. So you can now get these sensory devices running around relatively quickly and spend your time writing complex applications for them."

As an inexpensive wireless option, Bluetooth provides many advantages for robotics designers over other standards. First of all, it's low-power, so it doesn't guzzle batteries like many other wireless technologies. That's important, say, for small robots where every ounce counts -- an aerobot, for example, like the blimp or the Bluetooth-equipped microrobotic helicopter recently demonstrated by Seiko Epson Corporation. Bluetooth is also robust. The specification smartly contains several schemes that confirm whether a data packet made it to its destination untainted, and resends it if not. This gives roboticists the peace-of-mind that their machines can chit-chat uninterrupted as long as they're in range of one another.

"If you need low power and high error recovery, Bluetooth is the natural way to go to replace wires," says Jean-Christophe Zufferey, the lead graduate student on the robotic blimp project.

Right now, Zufferey, professor Dario Floreano and their colleagues are working on a Bluetooth-enabled robotic plane that also flies indoors. The 30-gram aerobot is outfitted with a tiny Bluetooth module to keep it in contact with its full-blown PC companion while allowing it to soar. Like the blimp, and a wheeled and wired robot before it, components of the plane are based on mother nature's ingenious engineering. The control system consists of a computer vision system, inspired by an insect's eyes, combined with so-called neural networks. Following Darwin's "survival-of-the-fittest" model, the computer runs an evolutionary process where the best code for the job emerges out of the virtual gene pool. Bluetooth enables the robot to evolutionarily adapt to its surroundings untethered from the PC driving the unnatural selection.

Of course, once the aerobots emerge from the laboratory for applications like traffic monitoring or search-and-rescue missions, Bluetooth may not be the ideal wireless solution. Most Bluetooth modules provide a range of just ten meters. Others can reach ten times farther, but consume far more power. Finally, the Bluetooth specification calls for just one megabit of bandwidth, far too little for telepresence.

Bluetooth's short range and low-bandwidth is less of a problem for professor Walter Potter of the University of Georgia's Artificial Intelligence Center. A few months ago, Potter and his graduate students published a scientific paper demonstrating a new way for robots to communicate and, amazingly, collaborate using Bluetooth.

In his demonstration, two small mobile robots collaborated on a "honeybee task," meaning they worked together like insects to locate a target in a room. The honeybee reference is based on the way each worker bee, when it discovers food, directs other bees in the hive to the treat. In Potter's experiment, the robots searched for a lightbulb in a large room.

The robots were based on a commercially available robotics kit that typically carries a Palm device as its onboard microprocessor. Potter and his team decided to outfit their bots with Compaq iPAQs specifically because of the PDA's Bluetooth capabilities.

While Bluetooth may not offer the security necessary for the military search-and-destroy missions Potter has in mind, the technology, he says, is incredibly useful for proof-of-concept demonstrations of "hive robotics" systems. The idea is that many small simple robots are more effective than a single complicated robot. If one breaks, the others pick up the slack. Coordination is key, especially as the number of robots on a team increases.

"If the communication system is robust and reliable, then the loss of one of the team members will only have a minor effect on the outcome of the task," he says. "The remaining robots could adapt their behavior based on the realization that one robot has been lost...This is particularly advantageous in our military-like scenario, where it is almost guaranteed that several of the robots will be lost before the task is complete."

The next step, Potter explains, is to enable the system to track moving targets and also jack up the Bluetooth functionality so that if a robot goes out of range by accident or to conduct independent reconnaissance, it can "reconnect seamlessly and easily to the rest of the group" upon its return.

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