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How can the inspection of a geometrically complex manufacturing fixture be accelerated while obtaining significantly more information about its actual geometry? For REVERSE-TECH, in cooperation with RICAIP Testbed Brno, we compared two approaches to the precise 3D measurement of a large aluminium manufacturing fixture. The aim was to assess their time requirements, accuracy, and practical applicability and to identify the optimal method for inspecting similar equipment. The experiment showed that 3D scanning can accelerate the inspection process while providing significantly more data. At the same time, it confirmed that tactile measurement remains essential for certain geometric features.
- Client: REVERSE-TECH
- Year: 2024
- Project duration: 2 months
Solution
Two methods for the precise inspection of a single fixture
The measurement system was based on the Leica Absolute Tracker AT960, a laser tracker designed for highly accurate measurement of large objects directly in industrial environments. Two measurement methods were compared when inspecting the manufacturing fixture. The first combined the laser tracker with an Absolute Scanner AS1 laser scanner. 3D scanning produced a dense point cloud representing the surface of the entire fixture, which was subsequently compared with its CAD model. The second method used a wireless Leica T-Probe. The operator used the probe to measure predefined inspection points, and the acquired values were compared with the nominal geometry of the CAD model.
From the CAD model to precise deviation analysis
Before the measurement itself, the physical fixture had to be accurately aligned with its digital CAD model. Using the laser tracker, the T-Probe, and the Best Fit method, spatial alignment was achieved with a deviation of approximately 0.08 mm. During 3D scanning, the individual surfaces were digitised and the results visualised using a colour deviation map. This made it possible to quickly identify both areas corresponding to the CAD model and locations with larger geometric deviations. For tactile measurement, individual inspection points were first defined in the CAD model and then physically measured using the probe. The result was a measurement report containing specific numerical deviation values.
Results
The comparison of the two methods revealed a significant difference, particularly in measurement speed and the amount of data acquired. Complete measurement and evaluation using 3D scanning took approximately 45 minutes, while inspection using the tactile probe required approximately 60 minutes. An even greater difference was observed in the amount of information obtained. While tactile measurement provided data from 204 inspection points, 3D scanning made it possible to evaluate nearly 24 million points distributed across the surface of the fixture. 3D scanning therefore provided a detailed overview of the geometry of the entire object and made it possible to identify local deformations or deviations that could remain undetected with point-based measurement.
Benefits of the Solution
The experiment confirmed that 3D scanning can significantly improve the efficiency of inspecting geometrically complex manufacturing fixtures. In less time, it provides comprehensive information about the actual geometry of the object and enables intuitive comparison with the CAD model. However, tactile measurement continues to play an important role when inspecting deep holes, hidden areas, and other geometric features that are difficult to access using optical methods. The greatest potential therefore lies in combining both methods – fast, comprehensive 3D scanning complemented by targeted tactile measurement of critical or difficult-to-access areas.
Potential Applications
A similar approach can be used to inspect geometrically complex manufacturing fixtures, moulds, tools, assemblies, or large industrial components. 3D scanning is particularly suitable where comprehensive information about the geometry of an entire object needs to be obtained quickly, where the actual condition needs to be compared with a CAD model, or where local deformations and manufacturing deviations need to be identified. The combination of optical and tactile measurement is also suitable for applications where rapid full-surface inspection needs to be complemented by precise verification of selected functional features or difficult-to-access areas.
Technologies Used
- Laser tracker: Leica Absolute Tracker AT960
- 3D scanning: Absolute Scanner AS1
- Tactile measurement: Leica T-Probe
- Evaluation: comparison of measured data with the CAD model, Best Fit alignment, geometric deviation mapping
Implementation
The project was carried out in 2024 in cooperation with REVERSE-TECH, RICAIP Testbed Brno, and CEITEC BUT. The equipment available at RICAIP Testbed Brno made it possible to compare two precision measurement methods in a real-world experiment and assess their suitability for the future optimisation of quality control processes at REVERSE-TECH.
