Ultrasonic inspection method and ultrasonic inspection apparatus
An ultrasonic inspection method in which a pulse signal is output to an ultrasonic sensor to generate and transmit ultrasonic waves, the ultrasonic waves reflected or scattered by an object are received and converted into a waveform signal by the ultrasonic sensor, and the waveform signal is digitized to acquire waveform data, includes: executing modulation processing for modulating a plurality of waveform data acquired in multiple inspections and under the same inspection conditions by a phase modulation method to generate composite waveform data; and executing demodulation processing for demodulating the composite waveform data to generate compressed waveform data.
1. An ultrasonic inspection method in which a pulse signal is output to an ultrasonic sensor to generate and transmit ultrasonic waves, the ultrasonic waves reflected or scattered by an object are received and converted into a waveform signal by the ultrasonic sensor, and the waveform signal is digitized to acquire waveform data, the ultrasonic inspection method comprising:
executing modulation processing for modulating a plurality of waveform data by a phase modulation method or a linear frequency modulation method to generate composite waveform data, the plurality of waveform data being acquired in multiple inspections and under the same inspection conditions or acquired by duplication; and
executing demodulation processing for demodulating the composite waveform data to generate compressed waveform data;
wherein in the demodulation processing, multiple types of matched filters having different phases are generated by numerical analysis based on the pulse signal, a convolution integral is performed on the composite waveform data using the multiple types of matched filters to generate multiple types of compressed waveform data, and a phase of the matched filter corresponding to compressed waveform data having an amplitude that is a maximum among the multiple types of compressed waveform data is acquired as a phase of the waveform data.
2. The ultrasonic inspection method according to claim 1 , wherein in the modulation processing, the composite waveform data is generated by a phase modulation method in which the plurality of waveform data is temporally shifted, multiplied by either a positive sign or a negative sign according to a preset code string, and added up.
3. An ultrasonic inspection apparatus comprising:
an ultrasonic sensor;
a control device that outputs a pulse signal to the ultrasonic sensor to generate and transmit ultrasonic waves, accepts a waveform signal in which the ultrasonic waves reflected or scattered by an object are received and converted by the ultrasonic sensor, and digitizes the waveform signal to acquire waveform data; and
a computer that processes the waveform data acquired by the control device,
wherein
the computer executes
modulation processing for modulating a plurality of waveform data by a phase modulation method or a linear frequency modulation method to generate composite waveform data, the plurality of waveform data being acquired in multiple inspections and under the same inspection conditions or acquired by duplication; and
demodulation processing for demodulating the composite waveform data to generate compressed waveform data;
wherein in the demodulation processing, multiple types of matched filters having different phases are generated by numerical analysis based on the pulse signal, a convolution integral is performed on the composite waveform data using the multiple types of matched filters to generate multiple types of compressed waveform data, and a phase of the matched filter corresponding to compressed waveform data having an amplitude that is a maximum among the multiple types of compressed waveform data is acquired as a phase of the waveform data.
4. The ultrasonic inspection apparatus according to claim 3 , wherein
in the modulation processing, the composite waveform data is generated by a phase modulation method in which the plurality of waveform data is temporally shifted, multiplied by either a positive sign or a negative sign according to a preset code string, and added up.