HoloPort - Submicron 3D measuring in the machine tool

The production of high-precision components requires accuracies that even modern processing machines often cannot reliably deliver. Worn tools, incorrectly calibrated sensors or inappropriate trajectories can lead to machining results that do not meet the required specifications. Quality control is usually conducted on a random basis in special measuring rooms, outside the machine tool. Monitoring and, if necessary, controlling the machining quality is a complex iterative process and has not been automated to date. We present the digital holographic sensor system HoloPort, which measures the surface topography of machined components with sub-micron accuracy directly inside the machine tool: To our knowledge, HoloPort is the world's first digital holographic measuring system for use in a machine tool. It not only consists of a multi-wavelength interferometer, but also contains a miniaturized graphics processor (GPU). This enables complete data evaluation directly in the sensor and thus in the machine tool. A single measurement with 9 million 3D points is carried out in wireless operation within less than one second and evaluated as well as transferred to an external computer in a total time of 3 s. The use of standard interfaces allows HoloPort to be easily integrated into a variety of machine tools. This article contains an overview of the sensor architecture and shows the performance of the system based on experimental results on milled parts. Inline applications as well as further perspectives opened by the sensor system are presented.