Bridge inspector

The changing effects of weather and temperature, road salt and traffic all take their toll on bridges, causing damage such as hairline cracks, flaking concrete and rust.

But up until now, inspecting a bridge has been a manual process - inspectors have always examined bridges for visible damage directly on site.

That's all set to change thanks to new image processing software developed by researchers at the Fraunhofer Institute for Industrial Mathematics in Kaiserslautern and scientists from the Italian company Infracom . The new software they have written can examine a photograph of a bridge for irregularities and then mark the respective area on the photo to alert an inspector to any problems.

Building the software was no easy task. Bridges all differ in terms of their shape, construction material and surface structure, while their colour depends on the material, the dirt or fouling, and the degree of humidity.

The software developers had to build a database of images featuring many different types of bridges that had experienced many different sorts of damage, while categorising the type of damage with the visual image itself.

But the results of the development effort have paid off. Now, when a new photograph of a bridge whose characteristics are unknown is presented to the system, that image is compared with those in the database. The software can then determine whether there are any irregularities. If there are, it marks the respective area on the photograph, allowing a bridge inspector to decide how serious the damage is.

Engineers have already been using the software over the past six months to inspect bridges in Italy.

'Unlike a human, the tool doesn’t miss any abnormalities - even minor damage is identified and signalled,' said ITWM scientist Markus Rauhut.