This paper presents a classification work performed on industrial parts using artificial vision, SVM and a combination of classifiers. Prior to this study, defect detection was performed by human inspectors. Unfortunately, the time involved in the inspection procedure was far too long and the misclassification rate too high. Our project consists in detecting anomalies under manufacturer production and cost constraints as well as in classifying the anomalies among twenty listed categories. Manufacturer’s specifications require a minimum of ten inspections per second without a decrease in the quality of the produced parts. This problem can be solved with a classification system relying on a real-time machine vision. To fulfill both real time and quality constraints, two classification algorithms and a tree based classification method were compared. The first one, Hyperrectangle based, has proved to be well adapted for real-time constraints. The second one, based on Support Vector Machine (SVM), is more robust, more complex and more greedy regarding the computing time. Finally, naïve rules were defined, to build a decision tree and to combine it with one of the previous classification algorithms.
In this paper, we propose a method of implementation improvement of the decision rule of the support vector machine, applied to real-time image segmentation. We present very high speed decisions (approximately 10 ns per pixel) which can be useful for detection of anomalies on manufactured parts. We propose an original combination of classifiers allowing fast and robust classification applied to image segmentation. The SVM is used during a first step, pre-processing the training set and thus rejecting any ambiguities. The hyperrectangles-based learning algorithm is applied using the SVM classified training set. We show that the hyperrectangle method imitates the SVM method in terms of performances, for a lower cost of implementation using reconfigurable computing. We review the principles of the two classifiers: the Hyperrectangles-based method and the SVM and we present our combination method applied on image segmentation of an industrial part.