334 results about "Laser ultrasonics" patented technology

Provided herein are the systems, methods, components for a three-dimensional tomography system. The system is a dual-modality imaging system incorporates a laser ultrasonic system and a laser optoacoustic system. The dual-modality imaging system has means for generate tomographic images of a volume of interest in a subject body based on speed of sound, ultrasound attenuation and/or ultrasound backscattering and for generating optoacoustic tomographic images of distribution of the optical absorption coefficient in the subject body based on absorbed optical energy density or various quantitative parameters derivable therefrom. Also provided is a method for increasing contrast, resolution and accuracy of quantitative information obtained within a subject utilizing the dual-modality imaging system. The method comprises producing an image of an outline boundary of a volume of interest and generating spatially or temporally coregistered images based on speed of sound and/or ultrasonic attenuation and on absorbed optical energy within the outlined volume.

A method and system is provided for enhanced ultrasonic detection and imaging of small defects inside or at the surface of an object. The Synthetic Aperture Focusing Technique (SAFT) has been used to improve the detectability and to enhance images in conventional ultrasonics and this method has recently been adapted to laser-ultrasonics. In the present invention, an improved version of the frequency-domain SAFT (F-SAFT) based on the angular spectrum approach is described. The method proposed includes temporal deconvolution of the waveform data to enhance both axial and lateral resolutions, control of the aperture and of the frequency bandwidth to improve signal-to-noise ratio, as well as spatial interpolation of the subsurface images. All the above operations are well adapted to the frequency domain calculations and embedded in the F-SAFT data processing. The aperture control and the spatial interpolation allow also a reduction of sampling requirements to further decrease both inspection and processing times. This method is of particular interest when ultrasound is generated by a laser and detected by either a contact ultrasonic transducer or a laser interferometer.

An ultrasonic non-destructive evaluation (NDE) system operable to inspect target materials is provided. This ultrasonic NDE system includes an articulated robot, an ultrasound inspection head, a processing module, and a control module. The ultrasound inspection head couples to or mounts on the articulated robot. The ultrasound inspection head is operable to deliver a generation laser beam, a detection laser beam, and collect phase modulated light scattered by the target materials. The processing module processes the phase modulated light and produces information about the internal structure of the target materials. The control module directs the articulated robot to position the ultrasound inspection head according to a pre-determined scan plan.

A method and an apparatus for non-contact and non-invasive characterization of a moving thin sheet and in particular of a paper web on a production line. The method uses a laser for the generation of sonic and ultrasonic waves in the thin sheet and a speckle insensitive interferometric device for the detection of these waves. The generation is performed in conditions to avoid damage impeding further use of the sheet. When the generation and detection spots overlap, the method provides a measurement of the compression modulus. When the generation and detection spots are separated by a known distance and plate waves (Lamb waves) are generated and detected, the method provides a measurement of the in-plane modulus and of the tension applied to the sheet. By detecting waves propagating in various directions, either by rotating the detection sensor head or multiplexing the signals provided by several detection or generation locations, the anisotropy of the in-plane modulus is determined.

A laser ultrasonic inspection apparatus and method which enables remote sensing of thickness, hardness, temperature and/or internal defect detection is disclosed. A laser generator impinges a workpiece with light for generating a thermo-elastic acoustic reaction in a workpiece. A probe laser impinges the workpiece with an annularly-shaped probe light for interaction with the acoustic signal in the workpiece resulting in a modulated return beam. A photodetector having a sensitive region for detecting an annularly-shaped fringe pattern generated by an interaction of a reference signal and with the modulated return beam at said sensitive region.

The invention discloses a method for utilizing a laser ultrasonic wave to precisely measure a third order elastic constant of metal. The method comprises the following steps: respectively measuring wave velocities of a longitudinal wave, a transverse wave and a surface wave excited by a laser under stress-free state and stress state; utilizing the wave velocities of the longitudinal wave, the transverse wave and the surface wave measured under stress-free state to calculate a second order elastic constant and a density of metal according to a sonic elasticity theory and a Rayleigh equation; utilizing the ultrasonic wave velocities of the longitudinal wave, the transverse wave and the surface wave measured under stress state to introduce an equivalent second order elastic constant and an independently measured linear coefficient of thermal expansion; and lastly, calculating the third order elastic constant according to the sonic elasticity theory. According to the method, a pulse laser source is utilized to excite a sound surface wave, non-contact exciting is performed under a thermal elastic system and an overheated phenomenon of materials is avoided, so as to realize nondestructive measurement. A large amount of sound surface wave data spread for different distances is collected and a correlation function is utilized to calculate a wave velocity of the sound surface wave and a spread distance of sound wave, thereby greatly reducing error of arriving time value of the sound surface wave and promoting the measuring precision of a sound wave velocity.

The invention relates to the field of steel rail flaw-detection, in particular to a steel rail flaw-detection method based on laser ultrasonic and high-speed photography image fusion. The steel rail flaw-detection method comprises the following steps that: step 1, a laser ultrasonic excitation module and a high-speed photography module are installed on a steel rail flaw-detection car; step 2, the steel rail flaw-detection car moves along a steel rail to be detected, meanwhile, the laser ultrasonic excitation module transmits a pulse laser to the surface of the steel rail to be detected, so as to obtain laser ultrasonic detection data; moreover, the high-speed photography module photographs the surface of the steel rail to be detected to obtain digital image signal data; step 3, the laser ultrasonic detection data and the digital image signal data are fused together, and the flaw conditions of the steel rail to be detected are judged. The invention provides a flaw-detection method for obtaining the state of the actually-flawed surface of the steel rail and position information while carrying out flaw-detection on the steel rail, thus realizing the effective fusion of the laser ultrasonic detection data and the digital image signal data.

Underfill voids and solder ball defects are detected via laser generation and laser detection of an ultrasonic wave at the top surface of flip chips. High resolution is provided by using small laser spot sizes and closely-spaced laser beams of wavelengths that are absorbed near the surface of the semiconductor. Alternatively, the generation laser beam may be absorbed in the bulk of the semiconductor. Improved spatial resolution and rejection of unwanted scattered waves can be attained by limiting the time frame of the ultrasonic waveform to the time required for the first longitudinal wave reflection from the bottom of the flip chip. The laser beam spacing can be reduced by using overlapping probe and detection beams of different wavelengths. Resolution of less than 100 μm features was demonstrated for silicon flip chips.

The invention discloses a laser ultrasonic thickness measuring method and a laser ultrasonic thickness measuring device capable of being used for field detection. The laser ultrasonic thickness measuring method is characterized in that a laser beam is sent out by a laser to excite an ultrasonic wave on the surface in a specific position of a measured object; meanwhile, an excited wave signal and an echo wave signal produced on the surface in the position are received by an air coupling sensor on the same side of the measured object as the laser; and the propagation distance of the ultrasonic wave is calculated according to the time difference between the excited wave signal and the echo wave signal, and a longitudinal wave propagation velocity of the measured object, so that thickness measurement of the specific position is realized. The device mainly comprises the laser, a main supporting seat, the air coupling sensor, a supporting rod, a centering device, a signal processing system and a display system. The device has a simple and light structure, and can meet the requirements of field detection; and through the adoption of the non-contact type detection method, the thicknesses of high temperature and high-corrosive measured objects can be measured.

The present invention provides a multi-mode calibration target operable to calibrate multiple optical sensors. One embodiment has multiple planar surfaces, wherein the multiple planar surfaces are able to be distinguished by visual sensors based on their color, hue, shade, tint, or tone. Additionally, these planar surfaces may be raised or recessed from one another to provide depth contrast as well as visual contrast. Other embodiments may include narrow band emitters such as laser diodes located at predetermined locations within the multi-mode target. These targets may then be used to calibrate various sensors, such as optical sensors, within an inspection system such as a laser ultrasonic inspection system.

The invention relates to a laser ultrasonic detection device and belongs to the technical field of laser ultrasonic detection. The device is composed of a crawling trolley, an optical fiber and an external control console, wherein the crawling trolley comprises a rotational scanning head, rolling wheels and stretching supporting bars, a box body and a fiber interface. A laser ultrasonic excitation source, a laser interference detection system and a data process system can be carried on the crawling trolley. Ultrasound is excited to generate on detected surfaces by lasers led into the trolley by the optical fiber or emitted by the laser ultrasonic excitation source carried on the crawling trolley. Ultrasonic signals are detected by the laser interference detection system carried on the crawling trolley and data are transmitted to the external control console for display by the data process system. The external control console is capable of monitoring the states of the trolley and controlling the trolley to conduct detection. The device of the invention is capable of conducting laser ultrasonic detection to pipelines on the problems of inwall surface damages, defects inside pipeline walls and the like. The device also has fast surface-scanning speed and high detection efficiency and is very practical.

A sheet material thickness online detection and adjustment system based on laser ultrasonic comprises a sheet material rolling mechanism and a sheet material thickness online detection mechanism. The sheet material rolling mechanism comprises an upper roller, a lower roller, an upper-lower roller interval adjust mechanism and a PLC control system, the sheet material thickness online detection mechanism comprises an optics system assembly, a high temperature testing meter, a data collection system assembly and a data process system assembly, the data process system assembly transforms bipolar signals which are aliased in peak values and complex in background noise into unipolar signals which are clear in peak values and low in background noise, so that the time that longitudinal wave and transverse wave reach the center of the bottom surface of the sheet material for the first two times is obtained, and thereby the sheet material thickness value is calculated, the measured sheet material thickness value is compared with a preset sheet material thickness value in the PLC control system, the PLC control system transmits forward rotating/backward rotation movement commands to a servo motor, so that the interval between the upper roller and the lower roller is adjusted, and the sheet material thickness value is made to be consistent with the preset sheet material thickness value.

The invention relates to a rapid detection method and a detection device for detecting diseases in a tunnel. The detection method comprises the steps of: detecting the lining thickness and a back cavity through an acoustic emission and laser vibration measurement technology; detecting the lining strength and compactness through the laser ultrasonic technology; detecting underground water behind the lining by utilizing an infrared temperature detection technology; detecting the degradation degree of surrounding rock behind the lining by using a laser scanning and inversion technology; and determining the position of the disease by using inertial navigation and image registration technologies. The detection device for detecting diseases in the tunnel comprises an acoustic emission and laservibration measurement module, a laser ultrasonic module, an infrared temperature detection module, a surrounding rock parameter inversion module and the like. The device runs once in the tunnel to obtain the disease features such as lining thickness and the cavity at the back of the lining, the underwater, weakening degree, the concrete degree and the compactness of surrounding rock, and comparedwith the existing inspection technology, the rapid detection method and a detection device have the advantages that the detection efficiency and the identification precision are greatly improved, thedisease positioning is more accurate, and the influence on the normal traffic driving is obviously reduced.

The invention relates to a laser ultrasonic detection apparatus, belonging to the technical field of laser ultrasonic detection. The apparatus comprises a detection laser source, a front light-splitting structure, a collecting structure, a double-photorefractive lens, (a) polaroid(s), (a) detector(s), a half-wave plate, a front polarization splitting prism, an acoustic-optical modulator, a back polarization splitting prism, a back light-splitting structure, a detected piece, a laser ultrasonic excitation source, a beam-expanding structure, a bidirectional tunable aperture and a focusing mirror. The apparatus is capable of carrying out wide-range laser ultrasonic detections and the speed of the laser ultrasonic detection can be greatly raised. A linear ultrasonic excitation source is adopted to carrying out the excitation, enabling ultrasonic fields of each monitoring point to have the same distribution, and thus solving the problem that the ultrasonic intensity at each collecting point is inconsistent with each other when circular laser spots are adopted to excite the ultrasound. The apparatus has fast surface-scanning speed and high detection efficiency, and is very practical.

An ultrasonic non-destructive evaluation (NDE) system operable to inspect target materials is provided. This ultrasonic NDE system includes an articulated robot, an ultrasound inspection head, a processing module, and a control module. The ultrasound inspection head couples to or mounts on the articulated robot. The ultrasound inspection head is operable to deliver a generation laser beam, a detection laser beam, and collect phase modulated light scattered by the target materials. The processing module processes the phase modulated light and produces information about the internal structure ofthe target materials. The control module directs the articulated robot to position the ultrasound inspection head according to a predetermined scan plan.

The invention relates to a laser ultrasonic detection device and additive manufacturing and detection integrated equipment. The laser ultrasonic detection device comprises a laser ultrasonic detectionprobe, an excited laser and a laser ultrasonic receiver, wherein the laser ultrasonic detection probe comprises a casing, a focusing probe arranged in the casing, a reflector, a receiving probe, a first lens, a second lens and an infrared thermometer. The temperature of workpieces is detected by the infrared thermometer in real time while defects are detected by ultrasonic waves, so that the defect detection accuracy is improved substantially. Meanwhile, the laser ultrasonic detection device cooperates with an industrial robot, a welding robot and a welding gun to realize independent operation of detection and additive manufacturing, and mutual interference is avoided.