Smart Joining and Measuring are the Basis of BMW’s Lightweight Material Mix
Lasers, Radar and Area Scanners: Modern QS Is Indispensable
Since 2016, the optical measuring cell at the pilot plant in Munich has been making an important contribution to the maturity of pre-series vehicles: with the aid of sensors, freely moving robotic arms take a three-dimensional picture of the entire vehicle. The resulting 3D data model has an accuracy of under 100 µm. This new technology was used for the first time in the production of the 5 Series BMW. As soon as a new model is transferred from the pilot plant to the production plant, tools for the production of serial parts form the body parts and replace the test tools used for prototyping, BMW explained. A further development of the Munich plant is now also used by the measurement technology specialists for car body construction in Dingolfing: the 3D surface scanning system.
Complete Body Measurement in Under Three Hours
A special feature of the latest system used in the series production plant is its ability to measure the entire body-in-white in under three hours — also with an accuracy of under 100 µm. No marks or other geometric references have to be attached to the bodywork for this measurement, which leads to additional time savings. Already in use at the start of series production of the BMW 5 Series Sedan, this system provided important insights into the fine-tuning of production systems and production processes. The measurement results are displayed in color, making them easy to interpret and error-free. During the start-up phase, the measuring technology specialists from Dingolfing assessed numerous car bodies. With the help of the particularly precise 3D surface data, a continuous assessment of the precision in car body construction is possible. According to the experts, corrections can be initiated immediately and deviations can be corrected quickly.
Identifying Defective Bolts by Radar
In the BMW 5 Series and BMW 6 Series GT, a laser radar system determines the exact position of the studs welded onto the floor assembly inline, i. e. directly in the production line. The philosophy of the closed-loop control system applies, because the high number of measured data makes trends recognizable at an early stage. Countermeasures can be taken long before deviations beyond the permitted tolerance occur. A major advantage of the measurement integrated into the production cycle is that immediately available measurement results also allow for immediate corrections. But the system can also offer the classical advantages of the measuring room, i.e. an accurate measurement. This is because, as in the measuring room, all components involved occupy a fixed position. The next step is the direct communication between the measuring system and the welding robot, which then independently corrects its settings. The idea for this expansion stage originates from the production staff and is an example of the interaction between the planning and production staff.
This article was first published by blechnet