Precise positioning brings clarity to the manufacturing process
Whether a screw connection will hold depends on a wide variety of factors. In a drilling machine, for example, the angle and torque of the screwdriver are decisive. This also applies to safety-relevant connections – in the automotive industry, for example. The NaLoSysPro project, which was completed at the end of 2018 and in which Fraunhofer IZM was also involved, aimed to make manually produced screw connections safer.
NaLoSysPro (from the German abbreviation for “near-field localization of systems in production lines”) helps to determine the exact position of the screwdriving tool at a manual workstation. The position data determined is stored in a database with parameters relevant to the screw connection, for example the torque. Each assembly step then has a complete data set that can be used to evaluate screwdriving processes and track any deviations from the process. This is made possible by four permanently installed radar stations and a mobile transponder on the screwdriving tool. The transponder transmits signals to the fixed units and these, in turn, use algorithms to calculate the transponder’s position. The miniaturized transponder was developed within the NaLoSysPro consortium and built by Fraunhofer IZM. For example, bumping technology for single chips was used during development at the institute. This is a rare niche technology that can be particularly useful in research and development projects where whole silicon wafers are too expensive or unavailable. Furthermore, experience in the field of transponder technology and antenna integration for radar applications was both gained and applied.