Analysis of the Accuracy of Virtual Clamping in the Field of 3d Scanning

Abstract

When measuring large and flexible parts, specialised measuring and clamping jigs are used as the standard, which fix the part to the required position. However, because the production of such jigs is time consuming and very expensive, software tools have recently started to appear on the market, which allow even large flexible parts to be measured in a free state and to use so-called virtual clamping for alignment the part in the mounting position. This technique uses the finite element method to simulate deformations during clamping. In this way, the inspection time can be significantly reduced and costs can be saved. However, the question remains how reliable and accurate this method is compared to the measurements in a physical jig. The article introduces the results of the analysis of the accuracy and repeatability of virtual clamping on the part "front fender of the Octavia car". The research showed that the conformity has not yet reached the values declared by the manufacturer, on the other hand, the measurement uncertainty during the virtual clamping was lower than during the measurement in a real jig. This, together with other indicators, indicates the great potential of the virtual clamping method in the future.

Comparison of optical 3D scanner and coordinate measurement system from the standpoint of macro-geometry measurement

“…If the surface does not have a matte finish, the obtained result can be distorted, often by a as much as one tenth of a millimeter [10]. They also investigated another important parameter of optical 3D scanning, which is clamping that can influence the results mainly in the case of measuring large and flexible parts [11]. It was found that the use of titanium powder is most suitable for measuring objects with high precision [12].…”