A technique detects an abnormal signal in a compound sampled signal recorded in the time domain. The technique involves dividing the sampled signal recorded in the time domain into sample segments; transforming each of the sample segments from the time domain into the frequency domain to determine transformed segments, each transformed segment having frequency points, each frequency point having an amplitude associated with a certain frequency; for a frequency point in a given transformed segment, determining a ratio by dividing the amplitude of the frequency point by a value indicative of an average of the amplitudes of the frequency points at the same frequency across transformed segments; repeating the determination of a ratio for frequency points in each transformed segment to determine ratios for each transformed segment; repeating the determination of ratios for transformed segments; and using the ratios to detect the abnormal signal in the compound sampled signal.

A technique detects an abnormal signal in a compound sampled signal recorded in the time domain. The technique involves dividing the sampled signal recorded in the time domain into sample segments; transforming each of the sample segments from the time domain into the frequency domain to determine transformed segments, each transformed segment having frequency points, each frequency point having an amplitude associated with a certain frequency; for a frequency point in a given transformed segment, determining a ratio by dividing the amplitude of the frequency point by a value indicative of an average of the amplitudes of the frequency points at the same frequency across transformed segments; repeating the determination of a ratio for frequency points in each transformed segment to determine ratios for each transformed segment; repeating the determination of ratios for transformed segments; and using the ratios to detect the abnormal signal in the compound sampled signal.

The invention relates to a method for rendering ultrasonic signals audible that is characterized in that the temporal dynamic range of the ultrasonic signal is maintained. The amplitude profile of the ultrasonic signal picked up in the time domain remains unaltered. The frequency shift from the ultrasonic range to the audible range is possible up to a factor of 32 using the present invention.

A method to monitor rotor blade vibration using unsteady casing pressure. The method applies a non-intrusive blade vibration monitoring technique by using an array of unsteady pressure sensors which may be flush-mounted in the casing of a compressor. The method comprises using spinning mode theory and temporal-spatial analysis to obtain frequency and nodal diameter information of spinning pressure waves associated with the rotor blade vibration. An example of the compressor can be a multistage axial compressor.

A method to monitor rotor blade vibration using unsteady casing pressure. The method applies a non-intrusive blade vibration monitoring technique by using an array of unsteady pressure sensors which may be flush-mounted in the casing of a compressor. The method comprises using spinning mode theory and temporal-spatial analysis to obtain frequency and nodal diameter information of spinning pressure waves associated with the rotor blade vibration. An example of the compressor can be a multistage axial compressor.

An abnormal noise determination apparatus including a microphone array disposed inside a vehicle and an electronic control unit including a microprocessor. The microprocessor is configured to perform acquiring an abnormal noise data on an abnormal noise generated by a sound source disposed in a predetermined position inside the vehicle, the abnormal noise data including an information on a strength and a generation direction of the abnormal noise collected by the microphone array in advance or assumed to be collected by the microphone array; acquiring a traveling noise data including an information on a strength and a generation direction of a traveling noise collected by the microphone array during traveling of the vehicle; and determining whether the abnormal noise is included in the traveling noise of the vehicle, based on the abnormal noise data acquired and the traveling noise data acquired.

A wedge for on-line inspection of a weld includes a wedge body defining a coolant channel and at least one couplant channel, and a coolant input port in fluid connection with a first end of the coolant channel. The wedge body has a surface for disposing a phased array ultrasonic transducer comprising an array of ultrasonic elements. The coolant channel is formed in proximity to the surface for disposing the phased array ultrasonic transducer such that coolant flowing through the coolant channel maintains the phased array ultrasonic transducer below a predetermined temperature without obstructing the array of ultrasonic elements.

An advanced acoustic awareness platform configured to classify environmental sounds. The advanced acoustic awareness platform comprises an audio signal acquisition sensor array and one or more processors programmed to augment the audio signal, extract features for the audio signal, visualize, and classify the signal using one or more labels. In at least one embodiment, the signal is classified based on transfer learning associated with a pretrained machine learning model.

A vibration sensor senses vibrations generated by an object to generate a noise signal. A processor obtains a structure vibration level spectrum from the noise signal, uses equalization parameters and A_weighting parameters to adjust the structure vibration level spectrum to generate a sound pressure level spectrum, and uses the sound pressure level spectrum to calculate a noise value of the object.

A vibration sensor senses vibrations generated by an object to generate a noise signal. A processor obtains a structure vibration level spectrum from the noise signal, uses equalization parameters and A_weighting parameters to adjust the structure vibration level spectrum to generate a sound pressure level spectrum, and uses the sound pressure level spectrum to calculate a noise value of the object.