A method for correcting a determination threshold of a floor medium and a method of detecting thereof are provided. The method is used for controlling a mobile robot equipped with a sound emitter and a sound receiver to detect and recognize the floor medium during a movement just started. A first detection result of a current floor medium is obtained by actively transmitting and receiving a sound signal, then, a to-be-adjusted detection result of the current floor medium is obtained only by passively receiving the sound signal through the sound receiver, and according to the similarity/difference of the two detection results, the determination threshold is corrected in the case of passively receiving the sound signal, so that the to-be-adjusted detection result is determined to be consistent with the first detection result.

This two-dimensional Fourier transform ultrasound imaging method includes by controlling transmitting and receiving transducers: obtaining M matrices MR.sub.m, 1≤m≤M, of sampled ultrasonic time signals; two-dimensional Fourier transforming each matrix MR.sub.m to obtain M spectral matrices FTMR.sub.m; converting each spectral matrix FTMR.sub.m to obtain M spectral images FTI.sub.m; combining the M spectral images FTI.sub.m and two-dimensional inverse Fourier transforming the resulting spectral image FTI to obtain an ultrasound image I. The conversion includes taking into account a change of propagation mode during a backscatter, by adding a parameter characterizing this change of mode in equations (SYS) of change of reference frame, and/or taking into account a reflection against a wall, by adding a phase shift term in a relation (REL) of matrix transformation.

An ultrasound instrument for detecting a measured value of a medium includes a measurement chamber having a chamber wall and a longitudinal axis; a pair of ultrasound transducers configured to transmit ultrasound signals along a signal path between ultrasound transducers of the pair through the measurement chamber and to receive ultrasound signals, wherein the signal path includes a signal reflection on a reflection surface, wherein the chamber wall in a region of the reflection surface opposite a first chamber side is configured to prevent a reflection of an ultrasound signal on a chamber outer surface of the chamber wall in the direction of the signal path, wherein the chamber wall has, in the region of the reflection surface, a maximum wall thickness which is at least a factor of 1.5 greater than a Rayleigh wavelength, associated with a central frequency, of the ultrasound signal in the chamber wall.

There are provided an ultrasonic waveform data generation unit (123) that generates ultrasonic waveform data representing amplitudes of reflected ultrasonic beams received by a reception unit (132) in time series for each of ultrasonic elements (111) forming reception ultrasonic elements (114), an ultrasonic waveform data processing unit (124) that uses a plurality of origin time adjustment patterns, in which a plurality of relative positional relationships between a phased array probe (110) and a welded portion (210) are set, and performs processing to synthesize pieces of the ultrasonic waveform data each having the adjusted origin time to generate synthesized ultrasonic waveform data according to each of the origin time adjustment patterns, and a defect evaluation unit (125) that evaluates whether or not a defect (211) is present in the welded portion (210) based on the synthesized ultrasonic waveform data.

Method for ultrasonic characterization of a medium, comprising generating a series of incident ultrasonic waves, generating an experimental reflection matrix R.sub.ui(t) defined between the emission basis (i) as input and a reception basis (u) as output, determining a focused reflection matrix RFoc(r.sub.in, r.sub.out, δt) of the medium between an input virtual transducer (TV.sub.in) calculated based on a focusing as input to the experimental reflection matrix and an output virtual transducer (TV.sub.out) calculated based on a focusing as output from the experimental reflection matrix, the responses of the output virtual transducer (TV.sub.out) being obtained at a time instant that is shifted by an additional delay δt relative to a time instant of the responses of the input virtual transducer (TV.sub.in).

Method for ultrasonic characterization of a medium, comprising generating a series of incident ultrasonic waves, generating an experimental reflection matrix R.sub.ui(t) defined between the emission basis (i) as input and a reception basis (u) as output, and determining a focused reflection matrix RFoc(r.sub.in, r.sub.out, δt) of the medium between an input virtual transducer (TV.sub.in) calculated based on a focusing as input to the experimental reflection matrix and an output virtual transducer (TV.sub.out) calculated based on a focusing as output from the experimental reflection matrix, the responses of the output virtual transducer (TV.sub.out) being obtained at a time instant that is shifted by an additional delay δt relative to a time instant of the responses of the input virtual transducer (TV.sub.in).

A non-destructive testing system includes a probe positioning assembly, a matrix array ultrasonic probe arranged on the probe positioning assembly configured to position the matrix array ultrasonic probe adjacent to a mating axial surface of a wheel for ultrasonic communication with the wheel. The matrix array ultrasonic probe is configured to emit a validation ultrasonic signal directed towards a coupling validation section within the wheel, measure the emitted validation ultrasonic signal after reflection from the coupling validation section, emit a plurality of ultrasonic inspection signals directed towards at least one inspection section of the wheel, and measure each of the plurality of ultrasonic inspection signals reflected from a defect positioned within the inspection section of the wheel.

An acoustic apparatus and method of determining the composition of a floor, based on the filtered sound waves produced by vibrating the floor is disclosed. The apparatus includes a transducer for generating vibrations and/or sound, as well as microphones for detecting sounds. The apparatus may include two microphones so that ambient noise can be removed from an audio signal.

Ultrasonic flaw detection uses a phased-array ultrasonic-flaw-detection probe. The flaw detection probe is placed such that the center of curvature of the flaw detection probe coincides with a reference center of curvature of a subject. The flaw detection probe is translated along a scan direction. The flaw detection probe emits an ultrasonic beam such that the position upon which the ultrasonic beam converges coincides with the center of curvature of the curve of the outline of the cross section of the subject at the scan position, receives the resulting reflected beam, and estimates the length of a flaw in the circumferential direction of the subject. In addition, the estimated length of the flaw is corrected using a correction coefficient corresponding to the distance between the center of curvature of the reference scan position and the center of curvature of the scan position in the thickness direction of the subject.

A measurement method is provided on an electrically conducting object. A first ultrasound wave is generated in the object by means of a first EMAT transmit transducer of a measurement arrangement. A first EMAT receive transducer of the measurement arrangement detects a first receive signal. The first receive signal comprises a first ultrasound signal resulting at least partially from the first ultrasound wave which has propagated through at least a part of the object, as well as a first electromagnetic interference signal. A second receive signal is also detected comprising a second electromagnetic interference signal by means of a first receive means of the measurement arrangement. The first receive signal and the second receive signal are processed jointly. At least the first receive signal is at least partially interference-suppressed.