Corrosion Detection for Industrial Objects: From Multi-Sensor System to 5D Feature Space

TL;DR

This paper presents a multi-sensor system combining RGB cameras and laser triangulation sensors to detect corrosion on industrial objects, utilizing a 5D feature space for improved classification accuracy.

Contribution

It introduces a novel data fusion method that combines 2D and 3D sensor data into a 5D feature space for enhanced corrosion detection.

Findings

5D feature space yields better classification results than 3D.

Multi-sensor fusion improves corrosion detection accuracy.

Data augmentation enhances model robustness.

Abstract

Corrosion is a form of damage that often appears on the surface of metal-made objects used in industrial applications. Those damages can be critical depending on the purpose of the used object. Optical-based testing systems provide a form of non-contact data acquisition, where the acquired data can then be used to analyse the surface of an object. In the field of industrial image processing, this is called surface inspection. We provide a testing setup consisting of a rotary table which rotates the object by 360 degrees, as well as industrial RGB cameras and laser triangulation sensors for the acquisition of 2D and 3D data as our multi-sensor system. These sensors acquire data while the object to be tested takes a full rotation. Further on, data augmentation is applied to prepare new data or enhance already acquired data. In order to evaluate the impact of a laser triangulation sensor for corrosion detection, one challenge is to at first fuse the data of both domains. After the data fusion process, 5 different channels can be utilized to create a 5D feature space. Besides the red, green and blue channels of the image (1-3), additional range data from the laser triangulation sensor is incorporated (4). As a fifth channel, said sensor provides additional intensity data (5). With a multi-channel image classification, a 5D feature space will lead to slightly superior results opposed to a 3D feature space, composed of only the RGB channels of the image.