Laser measuring technology. Applications for process and quality control in production lines

The majority of modern production processes has reached a high degree of automation. The involved process steps as well as the quality of the manufactured products have to be inspected on a routine basis. Online measurements offer the shortest possible reaction times for process control. Laser measuring methods are predestinated for this task: no mechanical contact to the specimen is required, high measuring speed, independence of ambient light, fast adaptation to varying technical surfaces of the specimens. During the last years, laser sensors for the determination of geometric features of workpieces were developed achieving a high level of performance for online measurements in terms of precision and measuring frequency. Furthermore the progress in signal processing, data evaluation and data assessment has accelerated the trend to completely automated inspection systems based on laser measuring technology. Multi-sensorial set-ups have been realized to measure geometric features of moving workpieces via a precise temporal synchronization of several laser sensors. This paper gives an overview of the features of those laser sensors and examples for the latest industrial applications.