Research of online measurement and inspection approaches for 2.5 dimensional workpieces

Abstract

By using online measurement and inspection, the efficiency of production in product manufacturing can be greatly improved. However, most of the available methods for the measurement and inspection of parts are offline in practice, which results in either time consuming or expensive inefficiencies. In this paper, a vision-based inspection approach is proposed, which is designed to measure and inspect parts with 2.5 dimensional shapes online within an appropriate accuracy. The hardware of the system includes: a scanner that is utilized to capture an image of the part to be inspected, a control device that manages the scanner so that it can capture the image at the appropriate time, a backlighting table that provides enough light to help acquire a clearer image, and a box to prevent outside light interference. The software of the system, implemented by using a Matlab toolkit, was used to perform the data processes, which consist of several modules including, but not limited to image segmentation, geometric feature extraction and calibration. To verify the validity of the measurement system, one simple part was used for testing purposes. The technique's efficiency was demonstrated by the comparison of the measured parameters with their actual values.