July 1, 2005 Researchers have developed a flexible, sensor-laden artificial antenna to help a robotic "bug" move and navigate just like the common cockroach. The bug can curry along walls, turn corners, avoid obstacles, and feel its way through the dark. In rescue operations, such robots could be sent to explore collapsed buildings and other situations that could pose hazards or just be inaccessible to humans.
WASHINGTON -- To most of us, cockroaches are a nasty nuisance. But engineers are now using them as role models for designing robots.
Now, mechanical engineers have a new bug-inspired robot device to send into risky rescues like earthquakes.
"The idea is that we want to make robots become more and more capable of going into dangerous environments without a human being there guiding it on every step," says Noah Cowan, who is a mechanical engineer at Johns Hopkins University in Baltimore.
Most robots can't "see" when lights are dim. But the key to this robot's success is its cockroach-like antenna that helps it scurry along walls, turn corners, avoid obstacles, and feel its way through the dark. "Our sensor is flexible and reaches out and touches an object, so if there's clouds or smoke, the sensor doesn't have a problem, it will still follow along the surface just fine," Cowan says.
The antenna is attached to a wheeled robot made of a flexible, rubber-like material. It has six embedded sensors. When one of them bumps into an object, it feeds an electrical signal to a tiny computer inside the robot, steering the robot away from or closer to the object.
"I envision not one or two but dozens of robots traveling through a building on their own," Cowan explains, "rather than one human operator trying to remote control a single robot."
Scientists are currently working on perfecting their roach-inspired robot before it can be made available to emergency response teams. Researchers are hopeful their roach robot will kick off an invasion of future rescue robots.
HOW IT WORKS: Most robotic vehicles designed to navigate dangerous terrain rely on artificial vision or sonar systems to find the safest path. But robotic "eyes" don't operate well in low light and sonar can be confused by polished surfaces. The Johns Hopkins University scientists have turned to touch, inspired by how bugs use this sense to navigate dark rooms with varied surfaces. Just like a cockroach's antenna, the artificial version sends signals to the electronic brain of a wheeled robot, enabling the machine to scurry along walls, turn corners, and avoid obstacles in its path.
The antenna is made of cast urethane, a flexible substance that resembles rubber, encased in a clear plastic sheath. It contains six strain gauges, sensors that change resistance as they are bent. The device has been calibrated so that certain electric voltages correspond to certain bending angles as the antenna touches the wall or some other object. This data is fed to the robot's controller, enabling it to sense its position in relation to the way and to maneuver around obstacles. For instance, when the antenna signals that the robot is moving too close to a wall, the controller steers it away.
WHAT IS SWARM INTELLIGENCE: Building "swarms," of robotic insects that work together to adapt to their environment is part of "evolutionary robotics": creating machines that are digitally "bred" to evolve themselves. Swarm intelligence is the notion that complex behavior can arise from large numbers of individual agents each following very simple rules. For example, ants follow the strongest pheronome trail left by other ants to find the most efficient route to a food source, through a process of trial and error. A chunk of the plot in Michael Crichton's novel Prey was inspired in part by an experiment in which a fleet of robotic predators were programmed to seek out "prey" to get their next energy boost. The mechanical "prey," in contrast, were programmed to "graze" on special light sources and to keep alert for potential predators. The respective robots evolved increasingly complex hunting and escape strategies as the swarms of robots accumulated more and more data (in the form of experience) on which to base their decisions.
ON THE WEB: Johns Hopkins University Robotics Research
The Institute of Electrical and Electronics Engineers, Inc. (IEEE), and the American Society of Mechanical Engineers contributed to the information contained in the TV portion of this report.