Robots use vision to navigate pipe
JUNE 30, 2008--Industrial pipe systems are inaccessible and narrow. The pipes can be vertical and have junctions. In addition, leakage points in the water system must be located, the condition of oil and gas pipelines must be checked, and ventilation systems need to be cleaned. Today's robots are not clever enough to face these challenges. They cannot climb or navigate in vertical pipes and very few have active joints.
Cybernetics and optical measurement scientists at SINTEF (Trondheim, Norway; www.sintef.no) are working on a solution. A team is developing an intelligent pipe-inspection robot on wheels that will be able to climb, navigate intersections, and at any given time know its location in the pipe system. The inspection robot will be able to move in pipes of various diameters, down to 20 cm. Cybernetics scientists are developing the propulsion system, while a team of optics scientists is working on the robot's visual system.
"We are currently developing the vision system that will enable the robot to navigate," says Jens Thielemann of SINTEF. "In the meantime, we are using the lego robot Mindstormer to collect the data to train the vision system. This lego robot has a camera attached and moves around the pipe following a preprogrammed map. The next step will be to utilize the vision system as input to control the actual snake robot we are going to develop."
The camera that will provide the robot's vision is an off-the-shelf time-of-flight camera that provides a bathymetric chart of the pipe system using inflected light. "Combined with our algorithms, the robot will be able to navigate and move forward on its own," says Thielemann. "The robot knows when a left or right turn is approaching and also contains a built-in path description detailing what tasks it should carry out in different situations.
The scientists have designed several versions of the pipe inspection robot and have tested different solutions to make the new robot both mobile and compact. They have now come up with a design they have faith in.
The scientists emphasize that the project is at the design stage. In June, two of the 11 joint modules will be tested to verify the concept, and they hope to demonstrate a prototype model by the end of the year. The final version of the robot will be constructed of aluminum and is planned to be 1.5 m long.