Detecting the smallest deviations with maximum flexibility

Non-contact 3D measurements and geometry inspection on complex objects can be applied in every manufacturing stage – from initial commissioning to first sample inspections on to automated sampling in series production – in order to quickly identify any non-compliance or error source to take corrective actions. FLEX-3A acquires the object’s 3D surface data with very narrow point spacing for all-surface target/actual comparisons. Particularly in the stamping industry, many manufacturers rely on the system of the image processing experts from Jena. "But other sectors are also growing. Particularly in the plastics industry we see a big potential”, explains Gunter Otto, Managing Director of OTTO Vision.

With this advanced product, OTTO Vision has streamlined the portfolio which now covers measuring fields from 20 mm to 200 mm by a single device. The optical approach was a particular challenge. As with previous products, just changing the lens should suffice to define the individual measuring fields, even from a fixed measuring distance.

FLEX-3A operates as all-automatic multi-view system based on phase-related structured light scanning with triangulation and photogrammetry. The 3D sensor holds two 12 megapixel USB 3.0 cameras and an LED light source with a resolution of 1440 x 1080 pixels. A third reference camera ensures multi-image registration. According to the complexity, the object can be illuminated and measured from several angles. A complete 3D scan is obtained by help of the optionally available motorized object frame.

This method of image acquisition is patented: "In addition to the two cameras on the 3D sensor we use a fix reference camera to determine the position of the object to be inspected. In this way, the partial views from different angles are put together to build up a complete 3D model using highly accurate and automated photogrammic transformation – completely without the need for physical targets, which saves time and money," Otto explains. The optionally available motorized object frame allows for all-automated measurements from top and below. This way, the universal system can be flexibly deployed for prototype sampling, automated sample checks in series production as well as for inspections on incoming machined parts.

Automated image data acquisition to form the 3D model including data calculation and evaluation is performed by high-performance software. The digitized data are either point clouds or meshed STL surfaces that can be directly aligned to the coordinate system of the reference model. This allows for a quick and easy-to-understand graphical target/actual comparison of manufactured parts against the corresponding CAD model. The comparison reveals any non-compliance to shape caused by distortion, shrinkage, object misalignment or even tool wear. The intuitive user interface allows direct and fast creation of any number of measurement plans, the simple setting of part-specific measurement parameters, the definition of automation sequences and the easy adaptation and optimization of the structured-light pattern. Furthermore, system recalibration within another measuring field is very simple.

With the new 3D scanner, USB cameras are premiering at OTTO Vision. "We have been successfully using Baumer cameras for many years. Due to the good cooperation and product reliability, it was clear that we would also use these cameras for the FLEX-3A," Otto explains. Combining high 12 MP resolution at 30 fps with a compact 29 x 29 mm form factor, the VCXU-124 cameras of the CX series perfectly match the system design requirements. The Sony Pregius CMOS sensor IMX304 delivers the excellent image quality required for 3D data acquisition. Thanks to USB 3.0 connectivity, OTTO Vision additionally benefits from a reliable single-cable solution with plug & play functionality saving time and money during installation. All-around M3 mount ensures convenient and flexible mechanical camera integration. Thanks to optimally synchronized cameras and digital projection, the image processing experts have succeeded in utilizing the full camera speed.