Safe inside their earthbound labs, NASA scientists recently used a remote-controlled robot to analyze rocks on distant Mars. Much closer to home, long-range robots are also unlocking the mysteries of another vast, unexplored region--the depths of Earth's oceans.
Shortly after the Mars Pathfinder showed how skillfully machines can explore another planet, scientist Robert Ballard announced that he had used an undersea robot to survey and recover artifacts from the largest concentration of ancient shipwrecks ever found in the deep seas. Louis Whitcomb, an assistant professor of mechanical engineering at The Johns Hopkins University, helped design this robot's navigation and control system and participated in the expedition. Whitcomb is pleased that mechanical explorers are proving their worth in high-profile missions.
"This is the golden age for robotic exploration vehicles," he says. "They're finally gaining credibility as an effective method of conducting research in inhospitable environments--both on Mars and at the bottom of the sea."
Some scientists argue that remote-controlled machines will never collect scientific knowledge as well as a human explorer could. But robots can do many important research tasks, Whitcomb says, without risking human lives and without the need to carry costly and cumbersome life-support equipment. "Robots have been most successful," he explains, "in tasks that are dirty, dull or dangerous."
Whitcomb has been working on systems that enable undersea robots to make visual records, create maps and pick up materials at depths far below those where human scuba divers and most submarines can survive. For the rare robot than can descend up to 6,000 meters or 20,000 feet, research opportunities abound. "We know more about the moon than we do about the floor of our own oceans," Whitcomb says.
One of the few machines capable of such dives is Jason, a 2,200- pound robot about the size of a Volkswagen Beetle. Jason was developed and is operated by the Woods Hole Oceanographic Institution. Whitcomb conducted post-doctoral research at Woods Hole and continues to serve as a visiting scientist there. During Ballard's recent expedition, Jason helped the research team explore ancient shipwrecks resting 2,500 feet below the surface of the Mediterranean Sea.
After the U.S. Navy's NR-1 nuclear submarine located the wrecked vessels, some more than 2,000 years old, Jason was sent down for a closer look. Equipped with video and still cameras, sonar devices, seven maneuvering thrusters and a robotic arm, Jason remained in constant contact with a surface ship via fiber-optic cables. During this expedition, a diverse team of engineering researchers developed and tested a new sonar-based navigation and control system that enabled Jason to perform the highly precise sonar and photographic surveys. The group included team leader Dana Yoerger of Woods Hole; Hanumant Singh, also of Woods Hole; Dave Mindell, of MIT; and Whitcomb.
The new system allowed Whitcomb and other team members to control Jason's movements with great precision. As Jason hovered about 10 feet above the ocean's floor, the team used the robot's cameras and sonar devices to make complete photographic records and detailed topographical maps of the shipwrecks. "We developed a new system that utilizes a doppler sonar to measure and control Jason's position and velocity," Whitcomb explains. "It exceeded our expectations. With this system, Jason can hover mere centimeters above delicate sea-floor sites and reach down with its robotic arm to recover artifacts and samples without disturbing the surrounding environment."
The engineering team's work was funded by the Office of Naval Research. The overall expedition was organized by Ballard, director of the Institute for Exploration of Mystic, Conn., a non-profit foundation dedicated to deep-ocean exploration. The expedition was co-sponsored by the National Geographic Society of Washington, D.C.
Control systems for underwater vehicles have been the principal thrust of Whitcomb's research since he joined the faculty of the Whiting School of Engineering at Hopkins in 1994. He and his students are continuing their efforts to expand the abilities of underwater robots, enabling them to conduct missions that were previously considered impractical or infeasible. "We build the 'brains' of underwater robotic vehicles," he says. "Our goal is to develop robots possessing dexterity and sensory capabilities exceeding those of humans, yet capable of operating in the inhuman environment of the deepest regions of the seas."
Whitcomb, 35, received his doctorate in electrical engineering and his bachelor's degree in mechanical engineering from Yale University in 1992 and 1984, respectively. In 1984-86 he was a research and development engineer with GM-Fanuc Robotics in Detroit. In 1993 he conducted robotics research in collaboration with Toshiba Corporation while he was a post-doctoral fellow at the University of Tokyo.
The Hopkins researcher is a recipient of a 1996 CAREER award from the National Science Foundation and a 1997 Young Investigator Award from the Office of Naval Research.
To learn more about Louis Whitcomb, Jason and robotics research, visit the following Web sites:
Louis Whitcomb's Home Page: http://spray.
Robotics Research at Johns Hopkins: http://robotics.
Johns Hopkins Dynamical Systems and Control Lab: http://spray.
Wood's Hole Oceanographic Institution: http://www.
The Jason Project: http://www.
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