291 results about "Speckle pattern" patented technology

The invention provides an intelligent real-time detection method and system for PCCP welding quality, and relates to the technical field of online detection and intelligent evaluation of pipeline welding quality through machine learning. Light energy data and multi-light-source images of a spiral weld pool are collected, exposure parameters are dynamically adjusted through the energy difference of visible light near-infrared bands, and the real-time detection of the PCCP welding quality is achieved. Inhibiting strong light interference and generating a weld surface image; a stress concentration area is positioned by scanning a welding seam thermal deformation area and combining speckle pattern change, sound frequency change and the elastic characteristic of the thin-wall steel cylinder; inputting the surface image and the deformation data into a space-time convolutional neural network, fusing light energy change, image details and spatial features to construct a weld joint space structure diagram, and adaptively correcting the position of a sensor; and comparing the sinking depth of the three-dimensional point cloud reconstruction, analyzing the correlation between the sinking degree and the stress, and generating a probability thermodynamic diagram to output the pressure-bearing failure risk level, so that the probabilistic early warning of the pressure-bearing failure risk can be realized.

The invention discloses a space-time speckle projection three-dimensional imaging method based on multi-frame optical flow alignment. Firstly, a projector based on DLP is used for projecting a space-time speckle pattern to a measured scene, and a binocular camera synchronously collects a three-dimensional space-time speckle image. The calibration parameters of the binocular camera are used to carry out stereo correction on an acquired original speckle image, and a parallax image is generated frame by frame in combination with a coarse-to-fine single-frame speckle matching strategy. And estimating a two-dimensional inter-frame displacement field between continuous disparity maps by using an optical flow method by taking an intermediate frame disparity map as a reference, compensating motion artifacts in a space-time speckle image, and ensuring strict space-time registration of a dynamic target. And based on the speckle image after motion correction, a speckle matching strategy is expanded to a time-space domain, and high-precision multi-frame three-dimensional measurement of a complex dynamic scene is realized. The method is suitable for performing rapid and high-precision three-dimensional modeling on a moving target in an unstructured environment, and can perform accurate three-dimensional measurement on a high-speed dynamic target undergoing any translation or rotation motion.

The invention provides a three-dimensional calibration method using a speckle image as a calibration object and combining weight parameters. The method comprises the following steps: acquiring a standard grid image and the speckle image through a camera; determining angular point positions in the standard grid image through an angular point detection algorithm; calibrating the stereoscopic vision system by using the obtained angular points to obtain an initial calibration result; calculating 3D coordinates of the camera calibration board in the world by using the disparity map; determining a subset of the reference image corresponding to the checkerboard angular points in the target image through a digital image cross-correlation algorithm; calculating a weight parameter of each calibration point based on the re-projection error; solving internal and external parameters of the camera by using the weight parameters, radial alignment constraint and a least square method; optimizing the main point of the camera by using the weight parameters; and if the re-projection error or the number of iterations does not meet the requirement, repeatedly calculating the weight parameter of the calibration point and the subsequent steps, otherwise, obtaining a camera calibration result, and obtaining the distortion curved surface of the camera lens.

The invention discloses an optical fiber coupling real-time correction method in a single-mode and multi-mode optical fiber endoscopic imaging system, which comprises the following steps of: firstly, manually adjusting reflectors M1 and M2 to an optimal multi-mode optical fiber coupling state, acquiring images of light spots at the near end and the far end of a laser beam in the state by using a CCD (charge coupled device) 1 and a CCD 2, and calculating the position of a central coordinate of the images; and collecting a speckle image formed by the light spot through the scattering medium by using a CCD3 (charge coupled device 3). The system monitors the center coordinates of near-end and far-end light spots at the current moment and the correlation coefficient of the current speckle image and the collimation state image in real time. The piezoelectric mirror bracket is fed back and adjusted in real time through the center coordinates of the two spot light spots and the correlation coefficient of the speckles, so that the correlation coefficient of the speckles is kept above a set threshold value, and automatic calibration of light beams is achieved. On the basis of the traditional thinking that two points determine one straight line, the correlation coefficient of using speckles is increased, the alignment precision is improved, and the method has certain practicability and application prospects.

The invention belongs to the technical field of three-dimensional vision measurement, and relates to a deformation measurement method and system of a composite vision measurement unit. The internal and external parameters of the binocular measurement unit are obtained according to the image of the thrust vectoring nozzle target area calibration plate; obtaining coordinates of all binocular measurement units in the same reference coordinate system according to the internal and external parameters and the images of the thrust vectoring nozzles with the first coded mark points, and obtaining coordinates of all binocular measurement units in a unified coordinate system; and acquiring full-field deformation of all target areas of the thrust vectoring nozzle according to the speckle images of the target areas of the thrust vectoring nozzle in the working state and the coordinates of the unified coordinate system of all binocular measurement units. According to the invention, a digital image correlation method and a close-range photogrammetry technology are utilized to realize coordinate system unification and full-field deformation measurement. Compared with a traditional method, the measurement times and data processing steps are reduced, and the measurement efficiency is improved.

The invention discloses a multifunctional asphalt mixture rut test method which is implemented by using a device integrating loading and measurement, test piece supporting and temperature control drainage, environment simulation and optical measurement and a central control and data acquisition system. A test piece is arranged in the test piece groove, temperature control is realized through circulating a heat-conducting medium in the temperature-conducting cavity, different gradients are formed through the hoisting mechanism and the angle adjusting assembly, the test wheel is driven to perform one-way circulating loading along a closed track and snub at a preset moment, and rolling and sliding friction forces are synchronously collected; in the test process, rainfall is simulated by adopting the watering assembly, incoming water is recycled by the drainage tank, speckle images are acquired by the high-frequency industrial camera, and surface full-field displacement and strain are obtained through digital image correlation analysis. Through time registration and fusion of temperature, gradient, wheel speed, rainfall and friction-deformation data, rut deformation, skid resistance and apparent structure evolution laws of the asphalt mixture under multi-climate and multi-gradient conditions are obtained.

The invention discloses a laser shearing speckle interference phase unwrapping method based on deep learning. According to the method, eight speckle patterns before and after deformation are used as input, multi-scale feature extraction is carried out through layer-by-layer convolution and down-sampling of an encoder, features are sent to an attention fusion module, response weights of channels and spatial positions are adaptively adjusted through channel attention and position attention, then the response weights are input into a decoder, and jump connection with an encoding end is combined, so that multi-scale feature fusion is realized. And step-by-step reconstruction of multi-scale features is realized, and a phase diagram is output. Performing comprehensive constraint on prediction and reference phases in the aspects of numerical deviation, structural consistency and gradient smoothness and updating network parameters by adopting composite loss formed by mean square error, mean absolute error, structural similarity, gradient loss and out-of-plane displacement calculation items; therefore, an unwrapping result which is globally continuous and has clear and stable local details is obtained, and a feasible way is provided for intelligent processing and automatic analysis of the laser shearing speckle interference image.

Provided in the present application are an image enhancement method and apparatus, an electronic device, and a storage medium, relating to the technical field of image processing. The method comprises: acquiring a medical data set, and collecting speckle images by means of an optical fiber endoscope; generating a synthetic data set on the basis of the speckle images and medical images in the medical data set; and performing adversarial training on a deep learning model on the basis of the synthetic data set and the medical data set to generate an image reconstruction model, so as to perform image reconstruction on endoscopic images on the basis of the image reconstruction model to obtain image reconstruction results. The present application solves the problem of poor image enhancement effect of image enhancement in the related art.

The invention relates to an automatic engineering crack detection device and method based on a bionic quadruped robot. The method comprises the steps that the distance between two cameras of a binocular camera and lens parameters are set according to the size of a to-be-detected structure; the 3D-DIC binocular detection equipment is adjusted to be in a horizontal state by adjusting the binocular detection equipment horizontal adjusting support; the 3D-DIC binocular detection equipment is moved to the front of the to-be-detected structure through the bionic quadruped robot, and the posture of the bionic quadruped robot is adjusted by using the quadruped robot overall adjustment gradienter to ensure that the detected area of the to-be-detected structure is located in the field of view; collecting a speckle image sequence of the surface of the to-be-measured structure through a binocular camera under the assistance of a light supplementing lamp; according to a preset strain threshold value, 3D-DIC analysis is carried out on the speckle image sequence through a crack recognition algorithm, a crack area is obtained, and parameters of cracks in the crack area are quantified. Compared with the prior art, the reliability of crack detection is improved, and accurate detection of crack parameters is realized.

The invention discloses an automatic detection method and system for the boundary dimension of a shield segment, and relates to the field of civil engineering, and the method comprises the steps: laying quantum dots on the surface of a to-be-detected shield segment, and exciting the quantum dots through ultraviolet laser to generate a fluorescence spectrum; the method comprises the following steps: receiving an optical signal penetrating through a medium gap in a to-be-detected shield segment through a single-pixel barrel detector to form a reflected light intensity sequence, and inputting the reflected light intensity sequence and a speckle pattern into a correlation reconstruction algorithm to generate a three-dimensional point cloud of a shielding area; and inputting the three-dimensional point cloud and the deformation compensation parameters into a deep learning network, generating a deviation thermodynamic diagram of the boundary dimension of the to-be-detected shield segment, automatically marking an area exceeding a tolerance threshold value based on the deviation thermodynamic diagram, and generating a detection result of the boundary dimension of the to-be-detected shield segment. According to the method, the internal medium gap is reconstructed through the single-pixel barrel detector and the basis tracking noise reduction algorithm, in a bolt hole oil stain shielding scene, compared with a traditional method, the reconstruction porosity error is reduced, and online analysis of the full-surface size error is achieved.

The invention discloses a forestry seedling culture data acquisition and analysis system, which relates to the technical field of data processing, and is characterized in that backscattered light of a seedling lignified tissue is acquired, an initial speckle interference video stream is generated, and after spatial image stabilization registration is performed on the initial speckle interference video stream, the speckle interference video stream is output; the correction module is used for obtaining a speckle interference video stream, extracting pixel time sequence gray information of the speckle interference video stream, mapping the pixel time sequence gray information into a time history speckle pattern, calculating a texture statistical characteristic value of the time history speckle pattern and outputting the texture statistical characteristic value as a first cell chaos degree index, and the compensation module is used for obtaining a metabolic rate compensation coefficient through a correction model. Temperature correction is conducted on the first cell chaos degree index according to the metabolic rate compensation coefficient, a second cell chaos degree index is output, the deviation degree of the second cell chaos degree index of the to-be-detected nursery stock and the dead wood reference value is calculated, the dormant state of the nursery stock is judged according to the deviation degree, and instant and accurate regulation and control over key nodes of seedling warehouse-out and recovery are achieved.

The invention discloses a non-contact measurement system and method for full-field deformation of a fuselage in an airplane crash test, and belongs to the technical field of airplane structure strength testing, and the method comprises the steps: making a high-quality speckle pattern on the surface of the fuselage, and laying cooperation mark points; a binocular camera flexible self-calibration method is used for completing calibration of the stereo measurement system; unification of global coordinates of multiple systems is assisted through unmanned aerial vehicle photogrammetry; a synchronous controller is adopted to trigger multiple sets of systems to synchronously collect images in the falling and collision process; obtaining the motion trail and speed of the key measuring point based on a mark point positioning tracking and stereoscopic vision principle; acquiring a full-field three-dimensional displacement field and a strain field based on a digital image correlation method guided by a control point and a stereoscopic vision principle; and deformation visualization representation is realized through image splicing and data fusion. According to the invention, non-contact, high-precision and full-field dynamic measurement of the three-dimensional deformation field in the falling and collision process of the whole large aircraft is realized, and technical support is provided for analysis and evaluation of falling adaptability of the aircraft structure and verification of anti-falling and anti-collision design.

The invention relates to the technical field of material detection, and discloses a semiconductor chip defect online detection system based on optical physical characteristics, which comprises a coherent light projection module, a reference light projection module, a displacement driving feedback unit, a discrete photoelectric detection array, a material support body and a logic processing unit, the displacement driving feedback unit acquires a rotating speed pulse signal, the logic processing unit calculates a laser sampling frequency and adjusts a pulse triggering time sequence, so that the axial displacement of the strip to be measured is constantly within a preset resolution range, the coherent light projection module and the reference light projection module project light beams at different angles, and a differential optical path is constructed; the discrete photoelectric detection array collects composite optical signals, the logic processing unit counteracts background phase noise by means of signal differential logic and extracts phase features of a speckle pattern to determine defect space coordinates, mechanical interference is stripped at a sensing source by means of a physical hedging mechanism, and optical dynamic ambiguity under the high-speed working condition is effectively eliminated.

The invention is suitable for the technical field of wavelength measurement, and provides a speckle wavelength measurement device with miniaturization and strong anti-interference, which comprises a single-mode fiber, a dislocation welding multimode fiber, a CCD (Charge Coupled Device) camera and a computer which are sequentially arranged along a light path, the single-mode optical fiber is connected with the dislocation welding multimode optical fiber; the dislocation welding multimode optical fiber is formed by a first short multimode optical fiber and a second short multimode optical fiber through axial dislocation welding. The CCD camera is connected with the dislocation welding multimode optical fiber; and the computer is connected with the CCD camera and is used for processing the speckle pattern acquired by the CCD camera. The device is small in size, and the stability, the anti-interference performance and the resolution ratio of a measurement system can be effectively improved.

This invention discloses a method and system for real-time stress monitoring during laser additive repair of fatigue long cracks in turbine casings. The method includes: preparing a high-temperature resistant speckle pattern in the pre-treated repair area; simultaneously acquiring a sequence of speckle images and a sequence of temperature field images during the laser repair process; calculating the strain field based on digital image correlation and calculating the real-time stress evolution using thermo-elastic-plastic stress-strain increment theory. The real-time stress value is compared with a dynamic threshold set based on the material's yield strength, and the laser power or scanning speed is controlled based on the feedback of the result to achieve closed-loop control of the repair stress. This invention achieves high-precision real-time online monitoring of stress under extreme repair environments, providing a basis for optimizing and intelligently controlling repair process parameters, effectively suppressing residual stress and the risk of secondary cracks, and significantly improving the repair quality and reliability of turbine casings.

The invention provides a two-dimensional visual residual magnetism detection damage evaluation method based on a neural network. On the basis of traditional one-dimensional residual magnetism detection, original magnetic field data in x, y and z directions in a space magnetic field are collected and further converted into dx, dy and dz component data, magnetic field intensity is synthesized, magnetic field data under seven different characteristic values are converted into 0-255 two-dimensional residual magnetism grey-scale maps through MATLAB, digital speckle images of corresponding areas are collected at the same time, and the residual magnetism detection accuracy is improved. The method comprises the following steps: performing mapping segmentation on two-dimensional residual magnetism grey-scale maps under different characteristics to form sample pairs, inputting the sample pairs into a convolutional neural network for training, outputting strain values under different two-dimensional residual magnetism grey-scale maps, being suitable for two-dimensional damage assessment of the ferromagnetic material, and being capable of realizing overall damage information of the surface of the ferromagnetic material and improving the accuracy of the two-dimensional damage assessment of the ferromagnetic material. The problems of missing detection and false detection in the one-dimensional residual magnetism detection process are effectively reduced, and implementation and popularization are facilitated.

The invention discloses a phase compensation method, device and equipment for a vibration error, a medium and a product, and the method comprises the steps: obtaining a dual-channel image of a to-be-detected object, carrying out the separation coding of the dual-channel image, and obtaining a speckle pattern under a red channel and three fringe patterns under a blue channel; determining the initial displacement of a local area in the speckle pattern under each frame; performing displacement iterative optimization on the whole image of the speckle pattern based on the initial displacement to obtain an optimal displacement; and performing reverse compensation on the three fringe patterns through the optimal displacement to obtain a compensated unwrapped phase. Accurate displacement is obtained through the red channel speckle pattern, the blue channel fringe pattern is reversely compensated, the displacement detection precision and the phase compensation reliability are both considered, and high-precision and real-time compensation of phase offset errors caused by vibration in the depth direction is achieved.

This invention discloses a three-dimensional contour measurement method and apparatus based on multi-projection gratings, relating to the field of three-dimensional topography measurement technology. The method includes: obtaining intrinsic and extrinsic parameters through calibration; projecting a set of speckle patterns; preliminarily analyzing the surface topography gradient of the object to determine a non-uniform spatial frequency sequence; sequentially projecting and acquiring multiple sets of phase-shifting grating patterns, and calculating the wrapping phase map corresponding to each frequency; for the same pixel, based on its reliability assessment in wrapping phase maps at different frequencies, assigning confidence weights to the phase values ​​of each frequency, and calculating and optimizing the phase map and the corresponding fused confidence map; calculating gradient information and combining it with the fused confidence map to perform region division, and executing a region-guided path consistency verification unfolding algorithm to obtain the absolute phase; converting the absolute phase into three-dimensional point cloud coordinates of the object surface. This application aims to solve the problems of complex topography, discontinuities, and noise easily leading to unfolding path errors and order jumps during phase unfolding.

A method for measuring the surface roughness of an object, wherein this method is: a) Receiving a speckle image showing an object while it is being irradiated by coherent electromagnetic radiation associated with wavelengths between 850 nm and 1400 nm, b) Determining the surface roughness measurement based on the speckle image, c) To provide the measurement value of the surface roughness, Includes.

To provide a technique capable of evaluating the state of stress on a plant body in more detail.SOLUTION: An evaluation method includes a measurement step and an evaluation step. The measurement step measures the state of a plant body at a plurality of different elapsed times. The measurement step includes an irradiation step of irradiating the plant body with a laser beam, a separation step of separating the laser beam with which the plant body is irradiated and that is reflected on the plant body into first linearly polarized light and second linearly polarized light, and simultaneously photographing the first linearly polarized light and the second linearly polarized light obtained through the separation in the separation step. The evaluation step evaluates a change with time of speckles in the first linearly polarized light and a change with time of speckles in the second linearly polarized light, from a plurality of speckle images acquired for a plurality of pieces of photographed data obtained through the photographing at the different elapsed times. The speckle images include the speckles in the first linearly polarized light and the speckles in the second linearly polarized light.SELECTED DRAWING: Figure 1

Methods and systems for agricultural monitoring are disclosed. The methods and systems include: projecting, by a light source, a coherent light output on at least a part of a plant material; acquiring, by an imaging device, one or more speckle images based on the coherent light output backscattered by at least the part of the plant material; providing the one or more speckle images to a trained machine learning algorithm; identifying one or more healthy status indications of at least the part of the plant material based on one or more outputs from the trained machine learning algorithm, the one or more outputs corresponding to the one or more speckle images; and providing plant health information based on the healthy status indication. Other aspects, embodiments, and features are also claimed and described.

The present application belongs to the field of aero-engine ground test technology, and provides an aero-engine test stand ground vortex test method and device. The method coats a brightening coating on the fan blades, rotating cap cover and inlet duct inner wall of the engine, and sets a background plate and a side high-speed camera on both sides of the inlet duct, wherein the background plate is opposite to the side high-speed camera and is in the field of view of the side high-speed camera, and the surface of the background plate is provided with a high-density random speckle pattern; the front high-speed camera is arranged opposite to the inlet duct to construct a double-view high-speed imaging system. When the engine is stably operated at a target speed, the double cameras are synchronously triggered to shoot image sequences; the cross-correlation calculation is performed based on the side image and the vortex-free background speckle pattern to generate a ground vortex center trajectory and fit a development curve; and the ground vortex centroid and cross-sectional area are determined based on the front image through a gray scale weighting method. The method does not need to invade the flow field, and can realize the synchronous quantification of the spatial evolution and cross-sectional morphology of the ground vortex.

This invention discloses a target classification method based on an event camera using a scattering medium, belonging to the field of target detection technology. The invention captures the speckle pattern formed by a moving target in the optical path as it scatters through a scattering medium, preserving the target's features. When the target moves, its corresponding speckle pattern moves as well. An event camera is used to capture the event stream triggered by the moving speckle. The event stream is then denoised and normalized using the event's timestamp and polarity information to create event frames. These frames are then fed into a densely connected neural network to complete the classification task. Multiple comparative experiments have verified that "event speckle" retains target features for event streams of different lengths and moving targets in different directions, and the target classification method based on "event speckle" achieves a classification accuracy of up to 92.92%.

This application provides a vibration element measurement device, comprising: a laser assembly for illuminating the test area of ​​the vibration element under test, wherein the surface of the vibration element under test located in the test area is provided with speckle patterns; two camera assemblies, respectively arranged on both sides of the test area of ​​the vibration element under test, for capturing speckle images of the vibration element under test during its movement; and a gimbal, on which the two camera assemblies are mounted, the gimbal being used for off-axis focusing of the camera assemblies. By arranging the two camera assemblies on both sides of the test area of ​​the vibration element under test and using the gimbal for off-axis focusing, the two camera assemblies can achieve full-field focusing of the test area of ​​the vibration element under test, thereby acquiring clear speckle images of each speckle pattern, thus achieving accurate measurement of the three-dimensional displacement and / or strain of the vibration element under test.

The application discloses a speckle quality evaluation method based on speckle gray scale distribution characteristic comprehensive parameters, and belongs to the related technical field of image measurement and optical measurement. The speckle gray scale distribution characteristic comprehensive parameters composed of speckle image average gray scale gradient, speckle image information entropy and speckle image autocorrelation parameters are used to comprehensively evaluate the quality of a speckle image. The speckle quality is comprehensively evaluated, more indexes are considered, and parameters are more comprehensive, so that the misjudgment phenomenon caused by single evaluation parameters such as average gray scale gradient and information entropy can be effectively improved. The speckle image autocorrelation parameter is used as a new parameter, and the whole speckle image is traversed, so that the contrast and randomness of the speckle image can be effectively considered, and high-quality speckles are screened out. The high-quality speckles screened out can improve the precision of processing displacement and strain of a digital image correlation system.

The application discloses a kind of multi-mode optical fiber wavelength multiplexing wide field imaging quality promotion methods based on dynamic calibration.The method comprises the following steps: collecting the output speckle pattern corresponding to each wavelength after being transmitted by multi-mode optical fiber;The speckle patterns of different wavelengths are spatially registered and spliced to form a high-dimensional composite speckle vector;PCA is used to bidirectionally compress the dimension of input image and composite speckle vector group, and a linear wavelength multiplexing inverse transmission matrix (WITM) is dynamically estimated and updated in low-dimensional space, and real-time pre-reconstruction and continuous monitoring are realized;Set up optical fiber state monitoring module to analyze pre-reconstruction frame in real time, when structural disturbance or optical fiber deformation is detected, automatically trigger in situ dynamic calibration, realize the rapid adaptive update of WITM, without retraining network.The updated WITM will guide the diffusion neural network image optimizer to iteratively denoise and detail repair the pre-reconstruction result, significantly improve the image fidelity and structure restoration ability.

The application provides a concrete carbonation depth detection method and device based on DIC technology, which comprises the following steps: (1) drilling a core sample on the surface of a concrete structure to be detected to obtain a standard test piece; (2) spraying a speckle pattern on the outer facade of the test piece and drawing a ring-shaped mark line at different height positions; (3) arranging at least one camera around the test piece and adjusting a DIC system support; (4) loading the test piece and synchronously shooting at least one camera to record a deformation image, so that a full-field strain deformation cloud chart of the outer facade of the test piece is obtained; (5) obtaining a maximum value of the concrete carbonation depth according to the strain deformation cloud chart mutation limit of the test piece and the ring-shaped mark line; and (6) repeating steps (4) to (5) to obtain the maximum value of the depth at least once, and calculating the average value of the concrete carbonation depth. The concrete carbonation depth detection method and device based on the DIC technology provided in the application are simple to operate and can improve the detection precision of the concrete carbonation depth.

The embodiment of the invention discloses a model training method, and the method comprises the steps: obtaining a sample image for a body tissue part of a sample user, and obtaining a corresponding initial sample speckle image based on the sample image through a target optical fiber; performing image quality enhancement and segmented adaptive normalization processing on the initial sample speckle image to obtain a target sample speckle image; training an initial image reconstruction model based on the target sample speckle image and the sample image to obtain a target image reconstruction model; wherein the target image reconstruction model comprises a feature extraction network; and the feature extraction network comprises a plurality of convolutional layers, so that the problem of insufficient image reconstruction quality in a complex multimode optical fiber imaging scene is solved. The embodiment of the invention further discloses an image determination method and device, equipment, a storage medium and a program product.