A voice-activated computing device configured to transmit a pilot tone and then capture or receive a signal, which corresponds to the pilot tone, reflected from within the environment containing the voice-activated computing device. The voice-activated computing device, or some other computing system or device, analyzes the received signal in order to determine analyze one or more characteristics present within the signal, i.e. noise, echo, etc. Based upon the analysis, models for signal processing can be determined, selected and/or altered. Future signals received by the voice-activated computing device can be processed with such models. The analysis can also allow for the models to be dynamically updated and for models to be dynamically created.

A sensor or receiver array includes first and second pyroelectrically active electrodes formed of polyvinylidene difluoride and separated by a spacer layer that acts to electrically separate the pyroelectric layers while keeping them close enough such that they see effectively the same vibration or background acoustic excitation while maintaining sufficient separation to ensure that they generate significant differences in their pyroelectric responses. The structure provides two distinct signals (at separate timestamps), the difference between which provides a more accurate signal. An ultrasound detection system includes the tri-laminar sensor, disposed within a detection zone in which a test element can be positioned. The apparatus includes a processing unit, which comprises a detector unit coupled to the first and second pyroelectric elements and configured to derive a differential signal from the first and second pyroelectric elements. A processor is coupled to the detector unit and is configured to generate an electrical output waveform on the basis of the data extracted from first and second pyroelectric elements.

A device for sensing a motion of a deflectable surface includes a deflectable element having a first side beam deflectable and includes a reflective surface at a second side of the deflectable element, proposing the first side. The device includes an optical emitter for emitting an optical signal towards the reflective surface and an optical receiver for receiving a reflected optical signal from the reflective surface and for providing a reception signal based on a reflective optical signal. The device includes a control unit in communication with the optical receiver for determining information related to the motion of the deflectable element based on the reception signal.

A pulsed laser interferometer includes: a pulsed laser; a vibration controller that produces a vibration control signal that controls a vibrational frequency and vibrational amplitude of a structural member; an interferometer controller; a pathlength control stage that changes an optical pathlength for laser pulses; a pathlength reflector that moves in concert with the pathlength control stage to change the optical pathlength of propagation for the laser pulses; a light pulse detector that produces a light pulse detector signal; an interference light detector that produces an interference frequency signal; a signal mixer that produces a reference frequency signal; and a phase-sensitive detector that produces a vibrational amplitude signal and a vibrational phase signal from the interference frequency signal referenced to the reference frequency signal.

Natural frequencies of vibration of objects, such as aerial vehicles, are identified based on imaging data captured while the objects are subjected to excitation. The imaging data is captured using high-speed cameras, and changes in intensities of pixels corresponding to surfaces of the object are used to determine a spectral diagram of the vibrations from which natural frequencies of vibration (e.g., vibration modes) are determined. The visibility of the vibrating objects is enhanced by providing video images to band-pass filters within small bands around the natural frequencies, and magnifying the vibration based on the amplitudes or phases determined from each of the video images. A stream of the modified video images may be used to determine a mode shape corresponding to the vibration of the objects at or around a natural frequency of vibration.

A method and a system for photoacoustic inspection of a part are provided herein. The method may include the following steps: photo-acoustically exciting a predetermined position in a predetermined region on a part by pulsed laser illumination, to yield ultrasonic excitation of the part; coherently illuminating a predetermined location in the predetermined region on the part; detecting an illumination scattered from the predetermined location; determining, based on the scattered illumination, a plurality of sequence of two or more temporally-sequential de-focused speckle pattern images, wherein each of the sequences corresponds to one of the predetermined illuminated locations; and determining a set of translations, each determined based on the sequences, wherein each translation in the set is determined based on two temporally-sequential speckle patterns images in the respective sequence.

A system and method can include a laser Doppler vibrometer (LDV) in optical communication with a part during manufacturing and a transducer in ultrasonic communication with the part during manufacturing. The system can also include a controller connected to both the LDV and the transducer. The controller may be configured to cause the transducer to vibrate the part during manufacturing at a predetermined frequency and the LDV may be configured to measure one or more mechanical response types of the part during manufacturing based on one or more optical characteristics of a reflected beam. The controller may further be configured to determine whether a defect is present in the part during manufacturing in response to the one or more mechanical response types of the part.

Appliances, methods, and systems (e.g., utilities) for use in analyzing received pressure waves to obtain and deduce various types of meaningful information therefrom (e.g., testing operation of an acoustic device that generates beams of acoustic energy). A pressure sensor in the disclosed system makes use of a piezoelectric layer or film (e.g., polyvinylidene fluoride (PVDF)) that has been substantially uniformly poled prior to interconnection with electrodes that are configured to send electrical signals to a controller or the like for generation of a dynamic, image (e.g., 2D) representing the received pressure waves. Among other advantages, the disclosed system leverages excellent economy of scale, can be configured in different arrangements with reduced cost, and limits the need for adapters or reverse engineering (e.g., as it can operate independently of the design of a probe or system under test.

Methods and systems for estimating a distance between an acoustic sensor and an acoustic reflector in a conduit are disclosed. One such method includes using the acoustic sensor to measure a combined acoustic signal that comprises an originating acoustic signal propagating along the conduit and an echo signal. The echo signal is generated by the originating acoustic signal reflecting off the acoustic reflector after propagating past the acoustic sensor. A frequency domain representation of the combined acoustic signal is determined and the echo signal is identified by identifying in the frequency domain representation periodic oscillations having a peak-to-peak difference between 0.75 Hz and 1500 Hz. The distance between the acoustic sensor and the acoustic reflector is determined from the velocity of the echo signal and a time required for the echo signal to propagate between the acoustic sensor and the acoustic reflector.

A photo acoustic non-destructive measurement apparatus and method for quantitatively measuring texture of a liquid. The apparatus includes a laser generating tool, an acoustic capturing device, and a data processing unit. The laser generating tool directs a laser towards a surface of a liquid contained in a container and creates pressure waves that propagate through the air and produce an acoustic signal. The acoustic capturing device records and forwards the signal to a data processing unit. The data processing unit further comprises a digital signal processing module that processes the received acoustic signal. A statistical processing module further filters the acoustic signal from the data processing unit and generates a quantitative acoustic model for texture attributes such as hardness and fracturability. The quantitative model is correlated with a qualitative texture measurement from a descriptive expert panel. Textures of liquids are quantitatively measured with the quantitative acoustic model.