Joint effort by USC College and Viterbi probes the mystery of toxic algal blooms
RoboDucks ship out and test the waters in Redondo Beach's King HarborBy Eric Mankin
June 1, 2007
Yacht-owners, kayakers, harbor patrolmen and sea lions are seeing a new vessel on the waters of Redondo Beach's King Harbor these days — a miniature sea craft that someday may save the lives of some of those same sea lions, as well as other marine mammals and birds.
Just under seven feet long, a fiberglass hull mounting a pair of cameras and a USC banner is making its way through the waves. It is key to biological research being done this summer to better understand and provide early warning of coastal algal blooms, including the 'red tide' algae infestations that commonly sicken and kill sea life.
RoboDuck1 (soon to be joined by sister RoboDuck2) is a robotic vessel with onboard sensors able to monitor water temperature, salinity, dissolved oxygen and turbidity.
The robots were created by a team from USC College and the USC Viterbi School of Engineering. They can cruise the harbor intensively and continually to gather data. The roving Roboducks will eventually be totally autonomous, going about their business without human controllers, navigating by GPS from sample point to sample point. Currently, they are operated by remote control and do some independent navigating.
The robot design team was headed by the Viterbi School's Gaurav Sukhatme, an associate professor of computer science and director of the USC Robotic Embedded Systems Laboratory. Sukhatme is working with Professor David Caron of the biological sciences department and the USC Wrigley Institute for Environmental Studies as part of the Networked Aquatic Microbial Observing System (NAMOS).
Caron, one of the world's leading experts on algal blooms, said that NAMOS and the ducks are designed to provide an early warning system for these sudden and unpredictable events.
"It's very difficult to be on the scene when the bloom is emerging," he said. "What you want is to be there with all your equipment studying what is happening as it begins."
But with limited budgets and boats, that has been impossible. By the time the bloom is detected, it's too late to do more than monitor the end stages. Caron hopes the robots can change this, working in the limited confines of the harbor they will be continually on duty. If their instruments detect an upsurge in algae, Caron and his entire team can immediately show up to do a complete analysis.
The data gathering ability of the robots are impressive They can lower a probe to take tests at various depths and they are able to also gauge algal density by measuring chlorophyll concentration in the water. Supplementing the ducks' data are readings from stationary instruments suspended from buoys and piers in the harbor. Crucially, the robots will have the ability to work with pre-selected sample points or to create new ones using data from the stationary network.
The hope is to find out what triggers such blooms, which can have catastrophic consequences for sea mammals and birds. As The New York Times reported in a June 5 story, "Southern California marine mammal hospitals have been overwhelmed by sea lions sick from the acid, which appeared in record levels off the coast of Los Angeles in April. Domoic acid poisoning has killed hundreds of the animals across Southern California this spring and thousands since a major outbreak in 2002, and has also afflicted animals in Monterey Bay, south of San Francisco."
The new ducks are second generation. The first, RoboDuck0, was a foot-long miniature custom design that served to work out some early issues. RoboDuck1 is based on a commercial vehicle called the Q-Boat, built by the Ocean Science groups of Oceanside California.
The off-the-shelf Q-Boats have remote controls, like those used for model cars. Sukhatme's team, consisting of computer science graduate students Amit Dhariwal, Jnaneshwar "JD" Das and Arvind Pereira, made wide-ranging modifications to the vessel to permit completely autonomous operation. Other Viterbi team members working on the project include technician Carl Oberg and computer science graduate student Bin Zhang.
Dhariwal worked to give the robot sonar-based mapping and exploration capabilities, ranging the bottom. Das specialized in the system design for the boat instrument controls, while Pereira created the GPS-based navigation system. In recent weeks, the system has been given a series of shakedown cruises and is on schedule to go into full operation by July.
"Networked robots such the roboducks are at the cutting edge of research in autonomous robotics." said Sukhatme. "On this project we’re building on several years of expertise we’ve developed in our lab mainly working with more conventional ground-based robots. We’re already working on extending the autonomous navigation, mapping and exploration algorithms we develop on this project to underwater robots."
Sukhatme and Caron emphasized that the King Harbor project has received vital support from Redondo Beach city officials and from the coast guard and harbor patrol. "They couldn't be more supportive," said Sukhatme. "Whenever we need something, they've gone out of their way to help."
The National Science Foundation has funded the project, as part of the Center for Embedded Networked Sensing (CENS) a science and technology center.