The new 3D multi-sensor system ZScan from senswork enables the seamless 3D scanning of large components. The modular concept allows direct integration into a wide variety of manufacturing processes for quick assessment of dimensional accuracy.

Production-accompanying 3D component measurements, especially on large and complex components, usually take place offline in measuring rooms. Experienced measuring technicians use a wide variety of measuring methods to determine the dimensional accuracy of the components and report the information to production. The major disadvantage of this method is the long measurement duration and the large time lag between the removal of the component and the determination of the measurement data.

Especially in connection with coordinate measuring machines (CMMs), a 100 percent test is ruled out due to the long measuring times. For some production processes, however, a 100 percent check or an inline check is necessary in order to identify and reject rejects as quickly as possible or to rework components.

Sensors with free spatial arrangement

With ZScan, senswork, an expert in industrial image processing, now offers a multi-sensor system that can be used close to production. Thanks to several triangulation sensors with free spatial arrangement, the system enables almost shadow-free detection and 3D measurement of large components. It is suitable for both inline and offline measurement.

The new technology consists of a high-precision linear axis and a multi-sensor head with up to eight profile scanners. Due to the inclination of the sensors both transversely to the transport direction and in the transport direction, as well as the flipping of sensors towards each other, areas that are difficult to access, such as undercuts or shadow areas, can also be detected.

Thanks to the arrangement of the sensors, there is a free point cloud with any spatial arrangement and density of points. This point constellation is comparable with the probed points of a CMM, but the number of measurement numbers is many times higher than with the CMM. The scan time per component is around 5 seconds. Up to 20 million measuring points are generated and processed per scan.

Specially developed 3D calibration

The unique calibration enables a free spatial arrangement of up to eight sensors. Thanks to the calibration with the specially developed, high-precision spherical targets, sensors can be calibrated with a free spatial arrangement and the scan data from the scanner can be spatially merged.

Unlike in the past, there is no need to always carry out a scanning process in an orthogonal alignment to the laser plane of a profile scanner. This avoids shadows. In addition, the principle can be applied to any number of spatially differently arranged profile scanners.

High-performance data processing

The extremely fast processing of the 3D data takes place in VisionCommander 3D. Be it the comparison against CAD, RPS alignments and point measurements to the reference system on the component, volume determination, position recognition or the detection of deformations or defects.

The framework also enables the algorithms to be used as a software library; it is not necessary to control an external inspection application. In addition, the connection to other machines or robot systems is possible so that the further processing of test parts can be 100 percent automated.

With this new type of process-accompanying 3D measurement, complex, tactile measurements are currently much easier. ZScan enables a multitude of new applications in production that were previously only possible in the measuring room. In the production of aluminum die-cast parts for the automotive industry, the scanning system records RPS-aligned measuring points on the component in order to correct it using this measurement data. Expensive gage-chek lessons will soon be a thing of the past.

Quality assurance in the automotive industry

In the production of so-called busbars, ZScan determines the form deviation of automatically manufactured busbars. The advantage: Thanks to quick, production-accompanying measurements and direct comparison with the underlying CAD model, correction parameters for feed and bending angle can be determined continuously and fully automatically for each segment.

ZScan brings the measuring room a big step closer to production. While range images (height images) have been used in classic image processing up to now, real 3D point cloud processing is also used in production with ZScan.