Soft sensor system for in-process eddy current microstructure characterization

Abstract. Non-destructive testing methods can be used for material characterization and quality control during manufacturing processes. For process control applications, a fast transformation of the measured signal to a small set of characteristic quantities is required. In this work, a soft sensor system based on digital data processing of an eddy current sensor system is developed and implemented. The analytical model for the voltage transfer function is based on an equivalent circuit for the sensor system. The data processing is implemented in software, and the resulting soft sensor is tested in experiments to show that it is possible to obtain useful material data for metals using comparatively simple sensor hardware in quasi real time.