Geometry Verification in the Automotive Industry

Mass production of industrial workpieces requires continuous manufacturing control to ensure constant quality. That is why assembly inspection is used to detect errors at an early stage. Many conventional inspection methods are still in use especially in the automotive and supplier industry. Traditional inspection with gauges is rather subjective and time-consuming. Moreover, such inspection only reaches an OK/NOK decision and measurement of actual dimensions is impossible. Furthermore, specifically controlling and improving the manufacturing process is also impossible. That is why the Fraunhofer IFF developed a measurement system that reliably inspects the geometric metrics of a manufactured item based on given reference data. This system uses structured laser light and the split-beam principle to capture the 3-D shape of a test item. Additionally, a multi-axis locomotor system moves the item in front of the sensors to capture the entire surface. Taking catalytic converters as an example, this article describes the configuration and functionality of the system as well as the algorithms used to verify the resulting 3-D point cloud against a given geometry.