Automated geometry measurement of wheel rims based on optical 3D metrology

One of the economically most important branches is the automotive industry with their component suppliers. The high degree of automation in manufacturing processes, requires automated control and quality assurance equally. In this scope, we present a complex 3D measuring device, consisting of multiple optical 3D sensors, which is designed to capture the geometry of wheel rims. The principal challenge for automated measurements is the variety of rims with respect to design, dimensions and the production flow. Together with connected conveyers, the system automatically sorts good rims without interrupting the manufacturing process. In this work we consider three major steps. At first we discuss the application of the used 3D sensors and the underlying measuring principles for the 3D geometry acquisition. Therefore, we examine the hardware architecture, which is needed to fulfill the requirements concerning to the variety of shapes and to the measuring conditions in industrial environments. In the second part we focus on the automated calibration procedure to integrate and combine the data from the set of sensors. Finally, we introduce the algorithms for the 3D geometry extraction and the mathematical methods which are used for the data preprocessing and interpretation.