Fraunhofer Institute for Physical Measurement Techniques IPM
The perfect alignment of camera sensors
The 100 percent inspection of components with a high degree of automation usually requires more than one sensor, as error tolerances vary depending on the component. An added difficulty is the need to test many different types of components while keeping the set-up for the testing equipment as simple as possible. Fraunhofer IPM develops optical inspection systems that utilize several cameras simultaneously with the aim of coordinating the different camera systems in a way that best meets the requirements.
More than the sum of its parts
In component inspection, the complete picture of a component does not become apparent until the various images are combined. Only once all the images have been reviewed and analyzed can components be categorized as good parts or scrap.
For example, the same area on a component can be inspected from different angles, and the inspection results on the individual images can be weighted accordingly. As a rule, geometrical deviations are measured based on a minimum of two combined images. Decisions are then made using adapted voting methods, which are mostly supported by machine learning.
At Fraunhofer IPM, we are able to set up camera systems with different sensors and to connect the data provided by them. For example, we combine different imaging techniques, such as fluorescence or directed and diffuse lighting. We also combine light field measurements with conventional images to maximize depth of field.
Exact comparison – in real time
The temporal and spatial synchronization of images are an essential part of any analysis. This is why Fraunhofer IPM has developed calibration routines, which determine the exact intrinsic and extrinsic parameters of each camera. This is the only way to ensure that the different images can be compared. Data is always combined and analyzed in real time, with low-level implementation of runtime-critical algorithms.
User-friendly handling guaranteed
Despite the large number of images, users stay on top of their production status at all times thanks to customized, hierarchical user interfaces. The top level shows the main inspection decisions at a glance. Intuitive menus allow users to drill down to raw image data and the individual evaluation steps, with the option of adjusting the focus where required.