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Measuring with CAD data

CAD data replaces the joystick

Another benefit of the CAD modules integrated into the measurement software is that the CAD information can be used to position the coordinate measuring machine. The entire measurement sequence can be controlled by selecting the geometric features on the CAD model. The measuring machine automatically moves to the generated measuring positions and measures with the selected sensors. This operating mode is known as CAD-Online® mode. In this way, for example, measurement points can be automatically captured as point clouds using styli or larger areas can be measured in high-resolution using the Werth 3D Patch or confocal sensors by automatically aligning the individual measurements. Technology parameters such as the illumination setting for the image processing sensor can be set directly on the measuring machine, taking into account the interaction between the illumination, measuring object and imaging system. Collisions are avoided by automatically modifying the movement sequences based on the workpiece and machine or sensor geometry

The measuring programme is created before the part

The same software can also be run on a CAD-Offline® workstation without the measuring machine. Here, the inspection programmes are only created and tested on the CAD model. Figure 56 images a 3D CAD model of a workpiece and the device simulation for offline programming. The collision analysis takes place in the background. CAD-Offline® saves expensive machine time. The test plans are already finalised when the first workpiece or measuring object is manufactured. Influencing factors related to the measurement object can then be reworked in a test run in single-step operation. Online and offline work can be carried out with a consistent operating concept; the measuring machine manufacturer ensures the "correctness" of the measurement results. This is not the case with programming workstations that are independent of the manufacturer.

The measuring programme is created before the part
<p>Fig. 56: CAD-supported programming with sensor simulation: image processing windows are displayed as green squares, scan lines of the laser distance sensor as green lines with blue direction arrows, measurement and clearance positions of the touch probe as yellow crosses and bypass paths as blue lines, if necessary with yellow touch probe simulation.</p>

Measuring with PMI support

Many CAD systems now offer the option of integrating PMI (Product and Manufacturing Information) data. In addition to the geometry description of the CAD features, the resulting CAD data sets also contain the dimensions defined by the designer. When the geometrical characteristics are selected, measurement points or scan lines are distributed across all geometry elements that are to be linked to find a solution, and the measurement sequence is created at least partially automatically. Due to the increased requirements when creating the CAD model, this solution is still not very widespread (as of 2019).