The paper presents research into line centre detection using a video positioning system, as part of a measuring system for line scale calibration. In the described approach, the video positioning system processes an image taken by a CCD camera to estimate the position of the observed line's centre. An important part of this research is also an analysis of line scale contamination's influence (scratches, dirt, usage, etc.) on line position determination. The outcome of the research is mathematical models that can be used as a base for developing a positioning algorithm. This algorithm is simple and adaptable to different types of line scales. It also includes a module for increasing the basic scale factor of the positioning as defined by the number of pixels in the CCD sensor, and a module for reducing the influence of contamination on positioning.
COBISS.SI-ID: 13642518
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
An empirical analysis is presented for researching linkages between manufacturing strategy, benchmarking, performance measurement (PM) and business process reengineering (BPR). Although the importance of these linkages has been described in conceptual literature, it has not been widely demonstrated empirically. The survey research was carried out in 73 medium and large-sized Slovenian manufacturing companies within the mechanical, electro-mechanical and electronic industries. The resulting data were subjected to reliability and validity analyses. Canonical correlation analysis was used to test six hypotheses. The results confirmed the need for a strategically-driven BPR approach and the positive impact of performance measurement on BPR performance.
COBISS.SI-ID: 13442838
This article has a twofold purpose. The first part deals with introduction of innovative high technology laser engineered net shaping (LENS) that offers a breakthrough in manufacturing, maintaining, and repairing products. It also presents many possibilities for the use of LENS technology, especially in the tool-making industry and for medical purposes. The second part presents a comparison of a product manufactured by conventional technologies and the same product manufactured by LENS technology. The product is a titanium alloy medical implant.
COBISS.SI-ID: 13243670
For decades three-dimensional (3D) measurements of engineering components have been made using fixed metrology-room based coordinate measuring machines (CMMs) fitted most commonly with single point or to a much lesser extent, scanning tactile probes. Over the past decade there has been a rapid uptake in development and subsequent use of portable optical-based 3D coordinate measuring systems. These optical-based systems capture vast quantities of point data in a very short time, often permitting freeform surfaces to be digitized. Documented standards, for example ISO 10360, for the verification of fixed CMMs fitted with tactile probes are now widely available, whereas verification procedures and more specifically verification artefacts for optical-based systems are still in their infancy. Furthermore, the industry is seeking traceability in 3D measurements of high precision components. A recent requirement is the demand for highly accurate measurements of large gears with diameters up to 1000 mm as used in gear boxes of wind turbines. Up until now it has been impossible to ensure traceability of 3D measurements of big gears, since no traceable standards were available. This paper describes three different types of artefacts that were developed during the project, namely tetrahedron artefacts for testing the basic measurement capability of optical 3D devices, freeform verification artefacts for testing the capability of measuring complex geometry, and a large gear artefact for task related calibration of different types of CMMs. In addition, artefact calibration data and associated measurement uncertainties and international inter comparisons are presented. These developments will be of considerable value to end users, calibration laboratories and producers of optical and tactile CMMs.
COBISS.SI-ID: 16149270