Powerline Eyes Help Prevent Bushfires

Australia's national science agency, CSIRO, and Powercor Australia have developed technology that will make it possible for power companies to measure the distance of tree branches from powerlines from the air. This will save money presently spent on manual inspection, particularly in rural areas.

The application was developed for Powercor Australia, the state of Victoria's largest electricity distributor, to automatically measure the distance of tree branches from powerlines, important in bushfire prevention and corridor mapping.

"Each year Powercor Australia spends millions of dollars making sure our electricity network is free from interference from trees and vegetation," said Powercor Australia's Manager of Technology, Bob Coulter.

"Trees coming into contact with powerlines can pose a serious fire risk to the community, as well as being a major source of power interruptions.

"Throughout the course of each year, our powerline audits involve a combination of aerial inspection and on-the-ground observation by patrolling crews," said Mr Coulter.

"This new technology will mean that ground patrols are only needed later, when tree branches actually need to be trimmed."

Since 1996, CSIRO has carried out several studies for Powercor to develop a cost effective airborne image capture and processing system to automatically measure the clearance of trees from powerlines.

Streams of colour stereo images were collected from an aeroplane flying above power lines carrying two cameras, one on each wing.

CSIRO image analysis specialists, Dr Changming Sun, Dr Mark Berman and their colleagues, developed software to identify objects such as powerlines, poles and the surfaces of nearby trees in three dimensions. The software can then measure distances from powerlines to trees.

"This technology is a form of stereo computer vision," said Dr Berman. "It reconstructs three-dimensional information from a sequence of stereo image pairs of a scene and uses it to measure distances."

"This is similar to how human vision works. The two cameras and a computer are like our two eyes and brain which seamlessly work together to estimate how far away objects are from us and each other."

"Unlike human vision, however, this technology can make very accurate measurements."

As well as assessing powerlines entirely from the air without the need for patrols to check them, the technology will give power companies a record of the state of their distribution assets at a particular date.

Mr Coulter said once the system has been commercialised, it would benefit a wide range of industries in the future.

"We particularly see great opportunities for organisations to use the stereo vision technology for other areas of corridor mapping, such as along roads and railways, phone lines, and pipelines for oil, gas and water."

CSIRO and Powercor Australia have just taken out a provisional patent on the technology.