Surface inspection using reflectCONTROL

In September 2007, Micro-Epsilon established collaboration with the BMW plant in Dingolfing, Germany, and the Institute for Software Systems in Technical Informatics Applications of the University of Passau (FORWISS Passau). This new joint research project was based on deflectometry software developed by Micro-Epsilon and Passau University and focused on developing a new optical measuring process for industrial quality control of reflecting surfaces. The Bavarian Research Foundation funded the entire two-year FORSO project.

Accomplishing innovative, visionary technologies or being a key part of their development has always been a particular challenge that the BMW Group likes to pose. Micro-Epsilon's well established deflectometry measuring technology, its position as a leading provider of high precision sensors, measuring devices and systems, and its close relationship with FORWISS Passau, made Micro-Epsilon an innovative, powerful technology partner for the FORSO project.

In the 3D measurement system for “rapid 3D shape measurement of reflecting surfaces”, the BMW Dingolfing plant has reached a milestone in the quality assessment of surfaces. One of the tasks of the paint specialists at BMW Dingolfing was to provide the necessary comparison data for the new measurement system.

An essential development step in the FORSO project and a key technical advantage of using Micro-Epsilon technology is its ability to provide additional, accurate 3D acquisitions of paintwork defects using this process. As well as providing the position of a defect on the car and its lateral extent, characteristic height and depth information can also be supplied at a resolution in the single-digit µm range.

Following several years of development, a number of car manufacturers now use the reflectCONTROL system in their production lines. Up to four reflectCONTROL systems are mounted to robots to control all vehicle body shells that pass through the test cell.

In addition to surface analysis for measurements, a marking technique was developed to visually identify and mark any defects directly on the car body. First applications of the robot-guided measurement technology show that this new, software-intensive inspection method for painted vehicle body shells finds significantly more paintwork defects than traditional manual inspection methods. And inspection times are markedly shorter, while inspection quality improves.