Imagine driving to work one morning and seeing something other than just birds perched on the power lines above. Then, imagine never having to guess or manually test power lines again.
Most power companies don’t know the weak points in their electrical grids, and although the power gets turned on after a storm, the long-term effects of hurricanes, landslides, wind or ice storms remain unexamined. Now, researchers at the University of Washington have developed a robot to crawl along power lines and detect problems.
“This is the first robot built that can inspect power cables autonomously looking for incipient failures,” said Alexander Mamishev, associate professor of electrical engineering at the University of Washington. “It can find cables that may need repair before they cause problems.”
The prototype robot has been developed over the past five years and tested on underground power lines at the UW. New Orleans was chosen for the field test because of the widespread damage to the city’s power system.
UW’s robot can pinpoint problem spots by using information from the surface of the cable to assess the condition of what’s inside. The robot, which looks like an insect and can negotiate tight curves, rides along the insulated distribution cable scanning for internal damage. It uses three sensors: a heat sensor that detects heat dissipation; an acoustic sensor that listens for partial electrical discharge; and a sensor developed by Mamishev that detects “water trees,” filaments of water that have seeped into the insulation. Engineers can monitor the robot through wireless connection and watch the robot’s surroundings through a front-mounted video camera.
While the threat from damaged power lines is most acute after a natural disaster such as Hurricane Katrina, the researchers say the robot could also be used for regular maintenance. “Right now, power companies either let a cable age until it fails, or they take out the entire line after a set time period,” said Luke Kearney, an electrical engineering undergraduate student working on the project. “Knowing whether the cable is starting to wear would save power companies a lot of money, and it would reduce the number of blackouts.” “Our vision is that someday robots will accomplish the lion’s share of maintenance tasks,” Mamishev said. EC