Innovative measuring process for surface inspection

Bavarian Research Foundation promotes collaboration project between BMW and Micro-Epsilon

The Bavarian Research Foundation is using € 650,000 to promote the collaboration established in September 2007 between BMW’s Dingolfing plant, Micro-Epsilon, one of the leading providers of high-precision sensors, measuring equipment and systems, and the Institute for Software Systems in Technical Informatics Applications (FORWISS Passau) of the University of Passau. The two-year research project involves the development of a new optical measurement process for the industrial quality control of reflecting surfaces.

In the automotive industry, s well as making purchasing decisions based on the functionality of products, consumers are also heavily influenced by the external appearance of the vehicle. The shiny surface of a vehicle is critical here, as well as the technology inside the car. However, perfect paintwork requires maximum attention during the complete painting process. Conventional measuring systems are often not sufficient to detect very small unevenness, bumps or roughness on the shiny, reflecting surface. However, the human eye of the customer can detect these imperfections very well. As a result, the consistent and intensive quality inspection of surfaces is becoming more and more important in the automotive sector. Innovative measuring processes and systems are therefore required. The objective of the research project is to develop these systems further.

Micro-Epsilon is one of the leading providers of high precision sensors, measuring equipment and systems. With more than 1,500 engineer-years of accumulated experience in the development, production and use of displacement sensors, Micro-Epsilon is a reputable industry partner to many companies throughout the world. This medium sized company located in Ortenburg has greatly contributed for almost 40 years to solving measurement and inspection tasks that involve displacement, distance and position measurement. The BMW Group is not a new collaboration partner for Micro-Epsilon. Together, the two companies have already developed a process for the partial measurement of raw plastic surfaces, which has been used in the BMW Landshut plant since Spring 2007.

The two companies are now working together with their collaboration partners on the development of a special 3D measuring system. The special feature here is that with this technique, the surface itself is not examined but its optically distorted or intensity weakening effect, which appear as irregularities in the mirror image of a pattern. This procedure makes it possible to accurately measure defects and shape differences even on reflecting surfaces. Dipl. Ing. Karl Wisspeintner, executive director of Micro-Epsilon, is convinced about the potential success of this innovative development. He sees clear possibilities to adapt the technique for other industrial sectors, for example, the glass industry. And he hopes to become a general supplier in the automotive industry with the newly developed system. The University of Passau is not an unknown factor either when it comes to research. It has already been performing analyses using digital image processing for several years for BMW’s Dingolfing plant.

Software from FORWISS Passau is already supporting the quality assurance in pilot production. By reverse engineering 3D measured data in CAD systems, accurate assessments of individual parts of the outside surface of the vehicle are possible. There are further collaborations with BMW Forschung und Technik GmbH in the areas of image processing, sensor data fusion and environmental detection for future driver assistance systems, which will further develop driver safety using active systems. The Institute for Software Systems in Technical Informatics Applications of the University of Passau has again been asked to carry out the current research project. Under the leadership of its director, Prof. Dr. Klaus Donner, Dr. Oliver Schwarz and Dipl. Mathematiker (graduate mathematician) René Schöne developed the mathematical model which makes it possible to process the acquired measurement data and evaluate this accordingly.

Developing innovative and visionary technologies and being involved in their research and development has always been an important objective at the BMW Group. In the 3D measurement system for “fast 3D shape measurement of reflecting surfaces”, the BMW Dingolfing plant, the largest plant within the BMW production network, sees a milestone in the quality assessment of surfaces. Therefore, the successful development, implementation and introduction of the system is critical for Klaus Musial, manager of the Dingolfing paint shop – also with respect to the development and plant network of the surface technology of the BMW Group. Among other things, the task of the paint specialists of the BMW Dingolfing plant is to provide the necessary comparison data for the new system. At a later time, the 3D measuring system should be integrated in a production line at the Dingolfing paint shop in order to test both the system as well as the technique under real operating conditions.

The research project of the collaboration partners BMW Dingolfing plant, Micro-Epsilon and the University of Passau is a further step towards the strengthening of Lower Bavaria as a region which is not only the home of innovation and research but also where these are driven forward.