3D Metrology

As a new business area, the topic “Metrology” is brought further into focus. Specifically “3D Metrology”. This is best described as digitally recorded specific geometries by means of a laser scanner.

The progressive use of 3D geometry in research and development, as well as in private areas, requires the delivery of geometry in a three-dimensional description. If no 3D model is available for this geometry, either because it has been lost or because there was no equipment for it at the time of creation, the subsequent acquisition of the data by means of 3D laser scan must be employed.

Below are some applications described in more detail.

Reverse Engineering

The term reverse engineering describes an inverted development sequence. Normally the 3D model is digital and is the basis for everything in the process chain, allowing one to extract documents such as the drawing, the NC model, the FEM model, or other technological sequences from which the physical part is ultimately produced. When working in reverse, however, the 3D model is fed back from the existing physical model. In this case the finished part is subjected to a 3D laser scanning from which a 3D model is created after several process steps backwards. It should be noted that this resulting 3D model is only an approximation. The 3D scan generates point clouds. After automatic or partly manual processing, surfaces arise which are defined as good approximations to superimpose these point clouds. We should also mention that the point clouds are also subject to variations. In most cases, these approximations are sufficient.

Digital Capturing of Environmental Geometry

Creating products that are to be inserted into an existing environment may require the presence of this environment in digital form. Since a manual measurement may not be possible due to cost or other obstacle reducing feasibility, all that remains is the digital recording of the environment by a 3D laser scanning. Depending on the situation, the quality of precision in such a case can possibly be reduced. Such detection may be implemented in a short time depending on the spatial extent.

TAILORED SYSTEMS created this 3D data acquisition system and is preparing three-dimensional geometry as per request.

3D Laser Scan

Capturing individual measuring points by means of so-called Tactile Scanning is a lengthy and often incomplete process due to the approach. The surface of the component is usually the determining factor in the selection of the probe diameter, as with cast pieces, for example.

Many materials can not be probed because of their soft texture. These primarily include rubber, foam, and other soft materials. For geometry measurements, a time-consuming probe change is additionally often necessary because of the dimension of the geometry. Scanning probe systems always require very complex and therefore also expensive and delicate additional hardware in conjunction with special software. After fastening the component, a further acquisition of data is only to a very limited extent.

Here, the full-surface survey of a component by means of a high-performance laser triangulation sensor is the method of choice. In contrast to tactile keys or tactile scanning, the contactless probing of a component is provided more quickly and with far more information.

A point density, which can be generated when scanning, is not accessible with a tactile system. Similarly, a detail of the smallest structures can still be measured. With conventional methods, however, there is no way to detect such fine structures. The main advantage over tactile systems, however, lies in the fact that after the survey of the surface, further editing of the measuring data is always possible. Even if the measured piece no longer exists, the point cloud can still be used.