The measurement service provider a3Ds from Braunschweig, Germany specializes in optical measurements. Components of different sizes are measured automatically and without contact. a3Ds works with state-of-the-art equipment that is found in many production lines.
To measure a SMART car, the a3Ds measurement technicians used two different methods. First, a 3D model of the vehicle was created using a LIDAR scanner, which is required for the subsequent digitisation. The geometry also served as a collision body in the GOM ScanBox.
Since the light beam passes through transparent surfaces during the LIDAR scan, the SMART’s windshield and headlight glass were sprayed with the self-evaporating AESUB blue Scanning Spray. The layer thickness of AESUB blue is between 8 μm and 15 μm, depending on the form of application. After AESUB blue was applied to the car parts, these parts were fully scannable for about an hour. The complete sublimation of AESUB blue takes less than four hours. The duration of the sublimation is significantly increased by spraying on several layers. The sublimation time is also influenced by factors such as temperature, air circulation and component structure.
Once the digital geometry from the LIDAR scan was available, the SMART was positioned in the GOM ScanBox and the scan routines were adjusted based on the data obtained. The measurement in the ScanBox was fully automated.
Even in the ScanBox, transparent surfaces cannot be scanned without treatment. The car was therefore sprayed again with an evaporating matting agent from AESUB. Due to the size of the component, AESUB green, which is available in container form, was used. The spray was applied with a spray gun so that the transparent and glossy surfaces were completely covered with a white, homogeneous layer within a few minutes.
AESUB green was optimised by the developers to have a minimum layer thickness. When applied with a spray gun, this thickness is between 10 μm and 20 μm. One litre of AESUB green can cover an area from 10 m² to 15 m². “AESUB green has the advantage that it stays on the component for a long time, so we have enough time to stick on measuring points. This means that there is no need to re-apply spray during the measurement,” says David Skuratowicz, managing director of a3Ds.
After the fully automated scan, the SMART was lifted out of the ScanBox again. The scanning spray evaporated on its own within a few hours without the need for subsequent cleaning. “It’s like magic,” said David Skuratowicz happily, “you come back the next day and everything is clean.”
For more information: www.a3ds.de