Automated Virtual Gauges for Dimensional Quality Control

Abstract

Dimensional quality control is a key issue in product manufacturing, particularly in long products such as rails or beams. To this end, international standards define precise methods to test if the dimensions are within the established tolerances, indicating whether they meet the required specification. The standards describe these methods using gauges that technicians can use to manually verify the dimensions of the product. In some cases, these methods provide different results from automated procedures, as they are based on different principles. To eliminate these discrepancies, this work proposes a novel automated method that emulates manual testing using virtual gauges. The proposed approach is based on an iterative procedure that aligns virtual gauges with the measured product shape, preventing one shape from penetrating another. This is achieved by assigning different weights to point correspondences according to their position. The result perfectly emulates the manual procedure, substituting the long and tedious manual procedure with a fast and robust automated alternative. Moreover, the proposed method can be applied to any dimensions with any type of gauge. Extensive tests with synthetic and manufactured rails corroborate the success of this approach.