Sterblue Blog


Image In → Defects Out. Automatic industrial defect detection with drones is now live

Article first published on August 19th, 2018.

These previous years, artificial intelligence algorithms (neural networks) have been brought to the forefront thanks to a hardware computation power increase and the labelling of huge data bases that made possible the pre-training of these algorithms. Thanks to a suitable training on thousands of labelled data, these algorithms can recognize some complex patterns such as animals, cars, bridges, etc.

This family of algorithms can perfectly be used on some industrial inspection applications and it works right now! A few golden rules and principles need to be respected.

  • This kind of algorithms are not just a pre-existing “magic algorithmic cauldron” that you feed with data expecting a pertinent result. It is necessary to develop and adapt these neural networks to specific industrial activities. Following the example of a human cognitive process, it is most of the time necessary to mix different neural networks. Each one of them is dedicated to a specific task : recognition, classification, segmentation, number of classes in a pictures, running in parallel or sequence, etc.
  • No quality labelled data, no result! Data must be collected and labelled following a rigorous and constant process: same distance and orientation acquisition, similar resolution, same exposure, same optical or infrared sensor, no blur, etc. This topic does not have to be under estimated in order to reach a good performance level
  • We often hear that millions of images or data are necessary to reach a high automation level for detection/characterization on images.Each industrial case is unique but usually a few thousands of labelled image are enough to kickstart the automation. Sterblue and its industrial partner Omexom have been working together on a neural network, dedicated to corrosion levels & bended bars detection on extra high voltage electrical towers. Training has been done on only 638 images (equivalent of 3 towers). Results are quite encouraging, with a false negative rate (defects not detected) of 2% and a false positive rate (false alarms) of 25%.

Reaching a 100% trust level in a the tool is a medium term project for industrials but this kind of tool can save time right now for job experts in their daily tasks.