Position gauging of welding joints with an FMCW-based mm-wave radar system

Abstract

This paper presents a position gauging system of welding joints. While the principle measurement concept was already introduced by Schrattenecker et al. in2014, here it is focused on different types of practically used welding materials. The sensor used is based on the frequency-modulated continuous-wave principle operating in the W-band. Position estimation (PoE) of different welding geometries is carried out with polarimetric scattering effects introduced by geometrical discontinuities. For the real-time calculation of the signal models a field simulation tool we developed is used. Aside from a variety of geometries, we introduce a geometrical optimization approach that increases the achievable accuracy of the measurement concept. The optimization and PoE of the different welding materials were examined in various simulations and the results were verified by measurements in the laboratory and in an industrial environment. Simulation and measurement were in good agreement.