In order to improve the existing comparative procedure for calibrating internal dimensions, we have developed a new measurement set-up for traceable absolute measurements. It consists of a co-ordinate measuring machine (CMM) and a laser interferometer (LI). The LI serves as a traceable measurement system, while the CMM is only used as a guiding system for the measuring probe. Extended research focused on defining probe parameters such as diameter, bending and indentation, as well as probing head repeatability and other error sources. The final goal of the research was to determine uncertainty of measurement under existing laboratory conditions. The main outcomes of the research and final uncertainty of measurement are presented in this article.
COBISS.SI-ID: 14652438
Non-contact optical three-dimensional measuring, scanning and digitising are increasingly present in quality assurance systems. Simple scanning procedures, high density of data acquired in a single scan, and the possibility of integrated reverse engineering and inspection, are all advantages of optical scanning compared to conventional measuring methods. Due to the three-dimensional acquisition of measuring data, an optical scanner is often considered to be an alternative possibility for coordinate measuring machines. However, the accuracy of the measured data acquired by optical scanning (even with a high-end system) is still far below the level achieved by high-level coordinate measuring machines. This paper examines the possibilities of using a three-dimensional scanner for workpiece inspection. The first part presents a special field of workpiece inspection in which, even with currently achievable accuracy, optical scanning is a viable solution for the inspection of manufactured parts. In addition, the achievable dimensional accuracy of an optical scanner is tested by scanning several gaugeblocks. In conclusion, a head to head comparison with a coordinate measuring machine is made by scanning and verifying a sphere.
COBISS.SI-ID: 15547158
In order to reach a high quality of the metal forming processes and full functionality of the products, the properties of the material have to be determined as precisely as possible. In this article, the evolutionary algorithms are proposed for the determination of flow stress for steel X22CrNi17. Two evolutionary algorithm methods were used: genetic programming (GP) and genetic algorithms (GA). On the basis of experimental data obtained during torsion test, various different prediction models for the flow stress curve were developed independently by the GP and GA. To make a comparison, the models for flow stress were also developed by standard regression method. Accuracy of the best models was proved with additional measurements. The comparison between the experimental results, regression model results, and the solutions obtained by simulated evolution clearly shows that the GP and GA approaches are very strong evolutionary tools for solving similar problems.
COBISS.SI-ID: 14890262