Crack detection system based on spectral analysis of a ultrasonic resonance signals

A real time crack detection system is presented in order to be used as a quality control strategy for syntherized metallic pieces. The signal processing algorithm is based on the spectral analysis of the signal measured by means of ultrasonic resonance inspection. The spectrum is obtained applying an FFT based chirp algorithm and from the resonance frequencies a minimum Euclidean distance algorithm, controlled by the false alarm probability, is applied to the cracked or defective pieces from the production system. The system has been tested in different production environments and with different types of pieces giving for all cases satisfactory results.