7 results about "Laser vibrometry" patented technology

The application relates to a laser vibration measurement optical device based on a Cassegrain system, which comprises a return light receiving optical system, a laser emission optical system and a heterodyne interference optical fiber system. The return light receiving optical system comprises a Cassegrain system and a receiving light interface arranged at the back side of the Cassegrain system. The laser emission optical system comprises an emission optical fiber interface and an optical path adjusting assembly, and the optical path adjusting assembly is arranged at the front side of the Cassegrain system and used for adjusting the emission optical path of the emission optical fiber interface so that the adjusted emission optical path is coaxial with the receiving optical path of the Cassegrain system. The heterodyne interference optical fiber system is connected to the receiving optical fiber interface and the emission optical fiber interface through optical fibers respectively, is used for emitting measurement light through the emission optical fiber interface, and performs differential signal detection according to reference light and return light received through the receiving optical fiber interface, so that the detection distance of laser vibration measurement is greatly improved.

A modal impact hammer and a method for vibration-testing a brake disc. The method comprises rotating the brake disc while it is meshed with a brake pad, exciting the brake disc by striking it with a vibration-exciter, in particular with a modal impact hammer and / or an electromagnet, and scanning the brake disc at different points with a laser vibrometer.

This invention relates to the field of pipeline quality inspection technology, and discloses a visual inspection device and method based on sewage pipeline production. The visual inspection device includes an inspection station frame, an outer insert, an inner insert, an elastic waveguide roller, and a laser vibrometer array. The outer and inner inserts are nested in a hierarchical manner, each equipped with an independent air-floating ring for segmental centering. The inner insert carries a small-diameter annular reflector that extends into the sealing groove area to perform circumferential surface imaging. The elastic waveguide roller has a multi-frequency piezoelectric excitation module embedded in it, which couples elastic wave pulses of different frequencies into the socket wall through an annular flange. The laser vibrometer array receives the scattered wave signals to calculate the depth of defects within the wall. All components use the inspection station frame as a common coordinate reference to achieve the correlation between surface defect data and wall defect data.

Techniques for generating a subsurface image include analyzing a region to be sensed to determine a plurality of reflector locations; and performing a survey. Performing the survey includes irradiating a plurality of reflectors positioned in the plurality of determined reflector locations with coherent electromagnetic energy; identifying one or more vibrations of the plurality of reflectors based on reflected electromagnetic energy from the plurality of reflectors; and generating survey data associated with the identified vibrations for at least one reflector of the plurality of reflectors. The techniques include providing the survey data as input to a machine learning algorithm; and generating, using the machine learning algorithm, a subsurface image associated with the region to be sensed.

An imaging system for multi-scale, non-contact US, PA, and FL imaging with a spatiotemporal sampling scheme, scanning with light integrated with mechanical mirror scanning pathway and testing instantaneous mechanical pressure and FL emission over target tissue surface. The imaging system provides deep and wide tissue imaging using a scanning laser vibrometry with broad tissue excitation using, for example, a tunable pulsed laser and fast microscopic imaging of identified regions of interest using an optic attachment to the camera to secure the tight focusing on the tissue surface. In some configurations, a raster¬ scanning photoacoustic imaging with a fast pulsed laser and parallelized data acquisition is used.

Method for detecting a vehicle (1) approaching on a roadway (2), wherein vibrations of the roadway (2) are detected, wherein the vibrations of the roadway (2) are detected by laser vibrometry, wherein a laser beam (7) is directed onto the roadway and a portion (8) of the laser beam returning from the roadway (8) is analyzed, characterized in that the vibrations of the roadway (2) are detected by laser vibrometry from another vehicle (9).

The invention relates to a diversity type laser vibration measurement optical system and a multi-set type receiving and transmitting separation assembly, which can solve the problem that the signal to noise ratio of a signal is influenced by vibration signal distortion and signal burr caused by a laser speckle phenomenon. The diversity laser vibration measurement optical system comprises a heterodyne coherent light system, a transmit-receive optical system and a diversity balance detection system. The transmitting-receiving optical system is correspondingly arranged in a measuring light path of the heterodyne coherent light system, and the transmitting-receiving optical system is used for transmitting the measuring light and receiving the reflected receiving light. The diversity balance detection system is correspondingly arranged in a reference light path of the heterodyne coherent light system, and the diversity balance detection system comprises a balance detection plate and a frequency mixing light splitting assembly. The frequency mixing and light splitting assembly is used for carrying out frequency mixing and beam splitting processing on the receiving light and the reference light so as to form multiple paths of frequency mixing light. And the balance detection plate is used for carrying out balance detection on the multi-path frequency mixing light.