PRISM Magazine Online - March 2000
teaching toolbox
On Campus
Send In The Robots

by Maryam Miller

Moccasin II That's what rescuers will soon be saying when a big quake or blast sends a building tumbling to the ground, trapping anyone who might be inside under piles of rubble.

After an earthquake or bombing, rescuers who climb into a fallen building in search of survivors hidden deep under the debris put their own lives at risk. But teams of engineering students at different schools are designing and building rescue robots to help solve this problem, and engineering a new approach to "search and rescue."

The pipe-crawling robot at North Carolina State University is designed to locate survivors without endangering the lives of rescuers. "The rescue robots would remove human operators from the danger zone," says Eddie Grant, a visiting professor of electrical and computer engineering and director of the Undergraduate Design Center at NC State.

Because pipes are often left intact following a quake or blast, the hope is that these robots could reach the deep interiors of a wrecked building. The most recent design, Moccasin II, looks a lot like an inchworm and moves with minimal impact on its surroundings. The robot's many segments expand outward and then pull the rest of the body forward, making it possible to navigate a complicated path, including 90-degree turns and vertical piping.

Moccasin II is outfitted with lights and a tiny video camera, which feeds images to the robot's operators through a cable so its location in the pipe can be seen. The robot can also carry sensors to pick up the vibrations from someone tapping on the pipes, or the warm presence of a person.

Howie Chaset, a Carnegie Mellon University professor, agrees that a snake-like shape may be ideal for a robot that needs to thread through piles of rubble. "A snake can slither through and find a person right away," he says.

But Chaset doesn't just want to find the people. His team of students is designing a robot that will be able to contact people who are trapped so they don't lose hope.

"[Hopefully] we can talk them through and improve their chances for survival," says Chaset, adding that robots might even be able to carry food, water, medicine, or radio transmitters to trapped survivors. But the snake doesn't slither on its own—yet. "We're making a snake robot that would be deployed from a larger unit," he said. "But we're designing it so we can eventually cut the cord and let it crawl on its own."

Chaset is also working with Robin Murphy, a professor at the University of South Florida, whose students designed a rescue robot with the marsupial system in mind. In this sense, "marsupial" refers to the pouch-like cavity within a big "mother" robot where a smaller "daughter" robot lurks.

The two-meter-long robot, called Silver Bullet, looks like a scaled-down Jeep and can climb over rubble. But if the mother robot hits a wall or some other snag, it sends out its "offspring"—a smaller robot named Bujold—from its internal hideaway. The "offspring"-bot remains tethered to Silver Bullet by a cable—like an umbilical cord—that delivers all its power and communication needs.

In addition to all the sensors and camera equipment Murphy's team is designing for the Silver Bullet-Bujold team, Murphy thinks it is important to maximize the robots' "thinking."

"You don't want the robot to think something is blood every time it sees red, or to wake up the operator every time it hears a noise," says Murphy. "Using human attention efficiently means utilizing rules of probability. We'd like to have the robots make those decisions as much as possible."

But one of the best features of rescue robots is that they are, well, machines. Dogs and people are good at finding survivors, but they might be killed in the process.

"If nothing else, these robots can be sent in front of rescue workers and dogs and make sure there aren't any dangerous gases or treacherous structures," says Murphy.

So, if something does go wrong in the search and rescue process, all that will be lost is a somewhat expensive piece of metal.

Maryam Miller is a former Prism editorial intern.

On Campus
A Tiny Team Wins Big

by Kelly Gordon

Scoot, Ray, Lars, and Major Tom are some of Cornell University's top soccer players. They're also less than 18 centimeters tall, battery-powered, and have been known to spin in circles uncontrollably and crash into walls.

These cube-shaped robots and their creators represented Cornell at the Robot World Cup Initiative, or RoboCup, held in Stockholm last August, in which 90 teams from more than 20 countries competed. Although it was Cornell's first RoboCup entry, their team, Big Red, became World Champions of the small size division.

Schools can compete in any of RoboCup's four divisions: small size; middle size; simulation, in which the game is played entirely on computers; and the Sony legged division, in which the corporation lends participating schools poodle-sized robots that have four legs, a snout, and a tail.

The RoboCup Federation, which sponsors the contests, is a collaboration between university and corporate laboratories around the world. Sony and Sun Microsystems underwrote last year's competition. The first RoboCup took place less than three years ago in Nagoya, Japan, and the organization's ultimate goal is to have a team of fully autonomous humanoid robots defeat the most recent World Cup soccer champions. An upset of this magnitude may seem unlikely, but as organization officials like to point out, it took only 50 years from the Wright brothers' first aircraft flight to the Apollo mission that sent men to the moon and only 50 years from the invention of the digital computer to Deep Blue, the computer that beat world chess champion Gary Kasparov.

Cornell's involvement with RoboCup began in 1998 with both undergraduate and master's engineering and computer science students signing up for a systems engineering class taught by Raffaello D'Andrea, an assistant professor of mechanical and aerospace engineering. The year-long course focused entirely on designing and building robots for the RoboCup competition. To concentrate on the whole system, the class was divided into mini-departments of electrical engineering, mechanical engineering, artificial intelligence, and team management.

Cornell's team says that what gave them the edge was their focus on designing and engineering the system as a whole, rather than a concentration on the computer programming that creates artificial intelligence (AI), or so-called smart machines.

"With a systems engineering approach, instead of an AI one, we were able to develop a better system," says Lars Cremean, who graduated last May with a bachelor's degree in mechanical engineering. "We concentrated on designing a system to play soccer, so if there were different conditions on game day, they could still cope."

The way the final design worked, a ceiling-mounted camera acted as the robots' eyes, and transmitted data to a computer, which then relayed the information to an AI computer that made the soccer decisions. By remote control, the AI told each robot where to move, kick, or turn and how fast to do it (top speed was two meters per second). Field players had a kicking mechanism that allowed them to push the ball while goalies were limited to a side-to-side motion.

The small size robots compete on a regulation size Ping-Pong table top, set on the floor with sides attached to keep the players from careening out of bounds. Each team can have up to five players, which kick or push a bright orange golf ball around the field during two 10-minute halves. The rules provide for timeouts which come in handy when one of the players short-circuits or loses parts on the field. "We designed our robots to be extremely durable, because as smart as they are, they're always banging into each other," says Aris Samad-Yahaya, who graduated last May with a bachelor's degree in electrical engineering.

Big Red faced another challenge when some of the team's bags were lost by the airline on their way to Stockholm. Besides clothes, they were also missing cabling for the camera, a wide-angle lens, and all of the batteries for operating the robots. The two and a half days scheduled for setting up and testing equipment were instead spent soldering cable and buying new batteries. The baggage showed up just before the competition, which left the team with time for only a few trial runs. As Samad-Yahaya explains, "once you press 'start' you can't do anything but look on and yell from the sidelines, just like a coach." Luckily, their robots had been in training for almost a year before their championship debut.

 

    Kelly Gordon is a Prism editorial intern.

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