The present invention relates to a technology for measuring a nonlinear parameter of an object to be measured, and more particularly, to an apparatus and method for measuring a nonlinear parameter of an object to be measured.

In a method of using an ultrasonic sensor comprising a two-dimensional array of ultrasonic transducers, a plurality of ultrasonic signals are transmitted according to a beamforming pattern at a position of the two-dimensional array. The beamforming pattern focuses the plurality of ultrasonic signals to location above the two-dimensional array, wherein the beamforming pattern identifies ultrasonic transducers of the two-dimensional array that are activated during transmission of the ultrasonic signals, and wherein at least some ultrasonic transducers of the beamforming pattern are phase delayed with respect to other ultrasonic transducers of the beamforming pattern. At least one reflected ultrasonic signal is received at the position according to a receive pattern, wherein the receive pattern identifies at least one ultrasonic transducers of the two-dimensional array that is activated during the receiving. The transmitting and the receiving are repeated at a plurality of positions of the two-dimensional array.

In a method of using an ultrasonic sensor comprising a two-dimensional array of ultrasonic transducers, a plurality of ultrasonic signals are transmitted according to a beamforming pattern at a position of the two-dimensional array. The beamforming pattern focuses the plurality of ultrasonic signals to location above the two-dimensional array, wherein the beamforming pattern identifies ultrasonic transducers of the two-dimensional array that are activated during transmission of the ultrasonic signals, and wherein at least some ultrasonic transducers of the beamforming pattern are phase delayed with respect to other ultrasonic transducers of the beamforming pattern. At least one reflected ultrasonic signal is received at the position according to a receive pattern, wherein the receive pattern identifies at least one ultrasonic transducers of the two-dimensional array that is activated during the receiving. The transmitting and the receiving are repeated at a plurality of positions of the two-dimensional array.

Methods, systems, and apparatus, including computer programs encoded on computer-storage media, for self-calibrating ultrasonic removal of sea lice. In some implementations, a method includes generating, by transducers distributed in a sea lice treatment station, a first set of ultrasonic signals, detecting a second set of ultrasonic signals in response to propagation of the first set of ultrasonic signals through water, determining propagation parameters of the sea lice treatment station based on the second set of ultrasonic signals that were detected, obtaining an image of a sea louse on a fish in the sea lice treatment station, determining, from the image, a location of the sea louse in the sea lice treatment station, and generating a third set of ultrasonic signals that focuses energy at the sea louse.

Photothermal imaging systems and methods are disclosed that employ truncated-correlation photothermal coherence tomography (TC-PCT). According to the example methods disclosed herein, photothermal radiation is detected with an infrared camera while exciting a sample with the chirped delivery of incident laser pulses (where the pulses have a fixed width), and time-dependent photothermal signal data is obtained from the infrared camera and processed using a time-evolving filtering method employing cross-correlation truncation. The cross-correlation truncation method results in pulse-compression-linewidth-limited depth-resolved images with axial and lateral resolution well beyond the well-known thermal-diffusion-length-limited, depth-integrated nature of conventional thermographic and thermophotonic modalities. As a consequence, an axially resolved layer-by-layer photothermal image sequence can be obtained, capable of reconstructing three-dimensional visualizations (tomograms) of photothermal features in wide classes of materials. Additional embodiments are disclosed in which the aforementioned systems and methods are adapted to photo-acoustic and acousto-thermal imaging.

A method and a test fixture for evaluating a battery cell composed of a cell body having a plurality of electrode foils, a positive terminal and a negative terminal, wherein the positive terminal and the negative terminal are each joined to the cell body at weld junctions. This includes retaining the cell body of the battery cell in a first clamping device. The terminal is grasped in a terminal gripper. A dynamic stress end effector coupled to the terminal gripper applies a vibrational excitation load to the terminal. A static stress end effector applies a static load to the terminal. Integrity of the weld junction is evaluated based upon the applied static load.

A method and a test fixture for evaluating a battery cell composed of a cell body having a plurality of electrode foils, a positive terminal and a negative terminal, wherein the positive terminal and the negative terminal are each joined to the cell body at weld junctions. This includes retaining the cell body of the battery cell in a first clamping device. The terminal is grasped in a terminal gripper. A dynamic stress end effector coupled to the terminal gripper applies a vibrational excitation load to the terminal. A static stress end effector applies a static load to the terminal. Integrity of the weld junction is evaluated based upon the applied static load.

A method for determining the directional frequency response of an arrangement of transducer elements. The method comprises providing a simulation of locations of the transducer elements, in the spatial domain; providing a beamforming direction and a frequency range; converting the simulation of locations from the spatial domain into corresponding frequency response values in a spatial frequency domain, such that, for each frequency of a plurality of frequencies in the frequency range, a spatial frequency contour is defined, each of the spatial frequency contours intersecting at the origin; determining the frequency response by applying a transformation to the frequency response values for the provided beamforming direction and frequency range, translating the spatial frequency domain into a modified frequency domain, wherein the contours avoid intersecting; and outputting the frequency response. There is further provided a data processing device adapted to perform the method, a computer program, and a computer-readable medium.

The present invention provides a defect analysis device including: an excitation unit (107) that imparts vibrations of a plurality of frequencies to a fluid (110) flowing through a pipe (108); a first detector (106) that, when the excitation part (107) is imparting vibrations, detects vibrations emanating from the pipe (108); and a signal processing unit (101) that extracts a feature quantity from a vibration waveform acquired by the first detector (106), and uses the extracted feature quantity to estimate the extent of a defect formed in the pipe (108).

The invention relates to a solution for how to measure the strain in a washer mounted in a bolt assembly comprising a bolt, nut and washer. The invention concerns a strain measuring washer assembly comprising a plate shaped washer body, sound emitting means and sound detecting means, and a method for using such.