Monitoring changes in contour of concave/convex point welding electrodes for motor vehicle manufacture using Doppler radar to measure spectra of moving welding point

摘要

The method involves using Doppler spectra of a welding point (1) moving relative to a microwave transmitter/receiver device (2). Before manufacture begins, the spectra of a number of differently shaped weld point contours are stored as reference spectra. By recording a first spectrum of one of a series of unused weld points, the associated reference spectrum is determined. During a production series, an actual spectrum is recorded after one or more successful welds have been performed. The actual spectrum is compared with the reference spectrum. If a deviation is detected only in a specific region that is more than a tolerance value, an output signal is generated. An apparatus for performing the method is also claimed.