2230 results about "Reflected waves" patented technology

A radar device which is installed in a vehicle or the like needs to detect a target at a short distance from several tens of centimeters to several tens of meters and, therefore, has a problem that a reflected wave from the target may be reflected by a front case of the radar device and then reflected by the target again to be received as a secondary echo by itself. To solve this problem, it is an object of the present invention to provide a radar device again that can prevent multi-reflection to accurately measure a distance to a target in a short range. In a radar device according to the present invention, a surface of a frame body provided around a transmitting antenna and a receiving antenna is shaped so that a reflected wave from a target may not be returned in a direction in which a transmitting wave is transmitted from the transmitting antenna.

The invention relates to the technical field of cable fault detection, in particular to a cable fault analysis system based on big data, which comprises a disturbance feature extraction module, a time sequence hierarchy judgment module, a reflection characteristic analysis module, a topological section identification module and a fault path mapping module. According to the method, gradient inflection points are extracted by calculating voltage and current increment included angles at adjacent moments, spatial-temporal characteristics of disturbance signals are correlated, interference of noise to a starting point mark is reduced, time difference is fitted in combination with cable length, deviation over-threshold abnormal points are dynamically filtered, influences of synchronization errors on sorting are eliminated, and fault path mapping stability is improved; the method comprises the following steps: generating characteristic parameters by fusing amplitude values and wave crest intervals of main waves and reflection waves, quantifying amplitude attenuation and phase offset coupling, enhancing the multi-path superposed signal separation capability, judging the reflection characteristic similarity of a physical section based on a Manhattan distance and a support vector machine, and dynamically dividing a fault section in combination with line topology. The problem of fuzzy positioning in a branch parallel scene in a traditional method is solved.

The invention discloses a target positioning method and system based on a single reference station, and relates to the field of wireless positioning, and the method comprises the steps: generating vortex electromagnetic waves carrying orbital angular momentum based on a transmitting end of a reference station, and generating a time-varying phase modulation transmitting signal and a metasurface time-varying coding sequence through a programmable metasurface; a time-varying phase modulation emission signal forms a multipath superposition effect in a propagation environment, a receiving end obtains a mixed signal of a direct wave and a reflected wave, and the receiving end carries out OAM mode separation on the mixed signal of the direct wave and the reflected wave through a spiral phase plate and an annular array to obtain signal components in different modes; and based on the signal component and the metasurface time-varying coding sequence, reconstructing an equivalent virtual array response by adopting a compressed sensing algorithm. According to the invention, the orbital angular momentum modal separation technology and the metasurface dynamic coding technology are creatively fused, and high-precision real-time direction finding in a complex multi-path environment is realized under a single base station architecture.

The invention discloses a power cable fault diagnosis and analysis method and system based on multi-source data, and relates to the technical field of diagnosis and analys.During operation of the system, various sensors are installed in a cable and the surrounding environment of the cable, operation data of the power cable are collected in real time, and after the collected multi-source data are preprocessed, the power cable fault diagnosis and analysis method and system based on the multi-source data are obtained. The method comprises the following steps: calculating key diagnosis parameters by using a machine learning algorithm, obtaining a comprehensive fault diagnosis index CDI, comparing the comprehensive fault diagnosis index CDI with a preset first threshold M and a preset second threshold N, obtaining a fault level and outputting a corresponding processing strategy, and carrying out fault point positioning by using a reflected wave method in combination with multi-source data according to fault characteristics and a cable model. And outputting a specific position of a fault point, accurately positioning the fault point in the cable, integrating analysis results of the modules, and automatically generating a cable fault diagnosis report which comprises a fault type, a fault point position, potential risk analysis and maintenance suggestions.

The invention provides a distribution line fault location optimization method based on single-ended traveling wave location, and relates to the technical field of traveling wave detection. The method comprises the following steps: carrying out segmented modeling on a line, calculating the traveling wave propagation speed and wave impedance of each segment, and correcting the traveling wave propagation speed and wave impedance; collecting a voltage / current traveling wave signal of a detection point, and extracting a line mode component; performing wavelet transformation on the line mode component, detecting the wave head position of the initial traveling wave through a modulus maximum search algorithm, and recording the arrival time of the initial traveling wave, a corresponding first energy value and polarity; calculating a reflected wave time window based on segmented modeling parameters, screening reversed polarity waves with qualified energy attenuation, and calculating a fault distance; if no effective reflected wave is detected in the reflected wave time window, triggering a pseudo double-end mode; a result is verified through quadruple constraints; the problems of poor parameter adaptability, low signal processing precision, strong reflected wave dependence and incomplete verification in traveling wave distance measurement of a complex distribution line are solved, and the accuracy and reliability of fault distance measurement are improved.

The invention provides a defect positioning accurate identification method considering the change of the section of a pile body, and the method comprises the steps: carrying out the simulation comparison of a constructed sound wave signal feature vector and a pre-constructed sound wave feature vector of a defect-free pile foundation, calculating the feature difference degree of the two, setting a difference degree threshold value, and if the feature difference degree exceeds the threshold value, carrying out the recognition of the defect-free pile foundation. If yes, preliminarily determining that the pile body has defects; on the basis of the adjusted sound wave detection, sound wave signals are collected again, signal processing and feature extraction are conducted through a self-adaptive path tracking algorithm, and the three-dimensional coordinates of the defect in the pile body are calculated according to the time delay and the propagation speed of reflected waves by combining the established multi-reflection model and an inversion sound wave propagation path; and according to the calculated three-dimensional coordinates of the defect reflection points, the influence degree of the defects on the bearing capacity of the pile foundation is calculated by combining the defect size estimated through the amplitude of reflected waves, the defect type recognized through waveform features and the strength parameter of a pile body material through a finite element method.

The invention relates to a settlement data analysis and early warning method based on a cloud platform, and the method comprises the steps: collecting settlement data of a basic part of a main transformer in real time through a high-precision electronic settlement observation device array, obtaining deformation stress data through data preprocessing and coordinate calculation, and uploading the deformation stress data to the cloud platform; transmitting an ultrasonic pulse signal to the stress concentration position of the local area through ultrasonic detection equipment, receiving reflected wave data, and identifying the depth and range of the crack initiation position according to the reflected wave data; a sensor array is arranged on the basic surface of a crack initiation position, sound wave signals released in the crack propagation process are captured, and a time sequence of the crack propagation direction and speed is determined; and detecting crack depth data of the repair priority region through ultrasonic waves, calculating an adjusted basic health state value, comparing the adjusted basic health state value with a preset safety threshold, and generating a corresponding safety early warning signal.

The invention discloses a power distribution network three-core cable fault distance measurement analysis method and system, and relates to the technical field of fault distance measurement, and the key points of the technical scheme are that the method comprises the steps: carrying out the empirical mode decomposition of three-phase voltage and current signals; generating a dynamic correction wave velocity based on the cable type, the environment temperature and the soil humidity parameter; determining the first arrival time of the wave head of the initial traveling wave according to the instantaneous frequency abrupt change point of the alpha-mode component, screening the second arrival time of the first reflected wave by using the amplitude gradient of the zero-mode component, and calculating the arrival time difference; and calculating an initial fault distance, and calling the impedance matrix to iteratively correct the initial fault distance. According to the method, the dynamic wave velocity is coupled with multiple factors, the limitation of single parameter correction is broken through, and the problem of transient drift of the wave velocity is solved; and the STFT high-frequency resolution and the wavelet low-frequency stability are fused, and the ridge continuity is optimized in combination with dynamic programming, so that the traveling wave head detection precision can be improved.

The invention discloses a concrete internal defect quantitative detection method and system based on reflected waves, and belongs to the technical field of nondestructive testing. A reflected wave data matrix is obtained through multi-angle excitation and synchronous receiving; calculating energy characteristics of each channel, and constructing an energy response residual field; extracting waveform offset, spectrum jitter and phase change caused by defects by adopting a disturbance comparison algorithm to form a disturbance feature vector set; a defect-response function curved surface is further constructed, a defect topological structure is inversed based on gradient and curvature analysis, and defect geometric parameters are output; and finally, inputting the multi-moment defect parameters into the recurrent neural network, and predicting a defect evolution path and a failure risk. The method has high resolution and trend prediction capability, and is suitable for detection and early warning of concrete structures in bridges, tunnels and nuclear power projects.

The invention discloses a textile production defect detection method and system based on image processing, and belongs to the field of textile defect detection. According to the method, the point cloud data is generated by collecting the surface deformation stripes, and the penetrability reflection signal containing the sound wave propagation time is obtained through the multi-frequency ultrasonic probe. Denoising the point cloud data and then positioning a surface deformation candidate area based on a curvature gradient and a normal vector deflection angle; and an internal abnormal region is determined by separating and extracting a reflection wave amplitude value and a time delay parameter through an ultrasonic frequency band. And matching the surface point cloud coordinates with the ultrasonic propagation time by adopting an iterative nearest point algorithm to establish feature association between the normal vector deflection angle and the reflected wave amplitude. And dynamically distributing fusion weights for the surface features and the internal features according to the curvature gradient change rate and the amplitude attenuation rate to generate a multi-modal defect distribution diagram. And geometric shape and reflection intensity parameters are extracted and matched with a preset defect template to realize type and position judgment, and the method can be suitable for production defect detection of the thick textile with a multi-layer composite material structure.

The invention relates to the technical field of power system fault positioning, in particular to a power distribution network fault accurate positioning method, device and system based on the traveling wave principle, and the method comprises the steps: deploying traveling wave detection equipment at two ends of a certain section of line of a power distribution network, and enabling the traveling wave detection equipment to be used for synchronously collecting potential fault traveling wave signals; analyzing based on the acquired potential fault traveling wave signal, and screening out a fault traveling wave; in the time union set of the local time windows at the two ends, marking the fault traveling wave with the maximum peak value in the single end as a direct wave, analyzing the waveform similarity between the direct wave and the fault traveling wave arriving after the direct wave, and screening out a reflected wave according to the peak value difference; and based on the arrival time of the direct waves and the reflected waves at the two ends, calculating the distance from the fault point to the two ends of the line through a positioning formula to position the fault point. The invention aims to improve the positioning precision of the fault point in the power distribution network by analyzing the distribution characteristics of the pseudo traveling wave signal.

The invention relates to the technical field of bridge pile detection, and provides a bridge pile foundation defect detection system based on an ultrasonic technology. The control terminal is used for controlling and managing the whole operation process of the system and monitoring data in real time; the multi-channel high-frequency ultrasonic detection module is used for transmitting ultrasonic signals through a multi-channel high-frequency probe array and receiving reflection signals in the bridge pile foundation to form original detection data; and the parallel computing and 3D imaging module is used for carrying out parallel computing processing on the received ultrasonic signal data and generating a three-dimensional structure image in the bridge pile foundation. The multi-channel high-frequency ultrasonic detection module is combined with the phased array technology and the multi-reflection wave processing technology, and high-precision detection of the internal structure of the bridge pile foundation is achieved. The phased array technology can flexibly control the propagation direction and depth of ultrasonic waves, and the coverage of a detection range and the resolution of signals are remarkably improved, so that the system can detect hidden defects such as micro cracks and holes.

The invention relates to a power distribution network cable fault wave head identification and positioning method and system based on sheath traveling waves, and belongs to the field of power system relay protection. According to the invention, cable fault condition identification is carried out by adopting a sheath traveling wave analysis method. The method comprises the following steps: carrying out identification and fault positioning on a power distribution network cable fault wave head by combining time-frequency analysis with high-pass filtering based on traveling wave time-frequency characteristics of a cable sheath. Firstly, traveling wave measuring points are set at the head end and the tail end of a cable sheath, transient information of the head end and the tail end of the sheath during cable operation is recorded in real time, zero-sequence voltage is set as a fault judgment quantity during cable fault, high-frequency transient quantity information of the cable fault is extracted for high-pass filtering, namely interference variables such as noise and harmonic waves in traveling waves are removed, and the fault judgment quantity is calculated. For the traveling wave signal after filtering processing, each wave head information of the fault traveling wave is calibrated by adopting time-frequency analysis, fault positioning is performed through position information of a fault initial wave head and each catadioptric wave head, a criterion is formed for cable fault positioning, the criterion is simple and reliable, the coupling degree with an actual line is relatively good, and the selectivity and the sensitivity are relatively high.

The invention relates to the technical field of power distribution network fault positioning, and provides a power distribution network multi-branch line fault positioning method and system based on time domain difference. The power distribution network multi-branch line fault positioning method based on time domain difference comprises the steps of obtaining a fault traveling wave line mode component based on fault traveling wave data, and performing discretization; performing time domain difference operation on the discretized fault voltage traveling wave line mode component, eliminating a sine component, and obtaining a fault traveling wave line mode component signal; constructing an objective function, optimizing a fault traveling wave line mode component signal, and determining a time domain position of a fault traveling wave head to calibrate arrival time of the fault traveling wave head; and if the fault is the trunk line fault, establishing a first fault point reflection wave time sequence constraint based on the basic parameters and the fault section of the fault line in combination with the fault traveling wave head arrival time, and determining the fault point reflection wave head arrival time so as to determine the position of the fault point. The calculation speed and reliability of fault positioning are improved, and the cost is reduced.

The invention relates to the technical field of communication, and discloses a high-precision measurement method for radial velocity of a shallow sea underwater acoustic target based on ray sound field reconstruction. According to the method, a multipath channel joint resolving system is innovatively constructed for the problem that the target speed measurement precision is limited due to a shallow sea complex propagation environment. According to the system, a compound ray model of shallow sea multipath sound propagation is established, and a joint representation equation containing channel impulse response and target motion parameters is constructed by analyzing a time delay-Doppler coupling mechanism of three typical paths of direct waves, water surface reflected waves and water bottom reflected waves. Especially for the multipath interference effect in the shallow sea waveguide environment, the time-frequency domain separation criterion of each path signal is deduced, and a theoretical basis is laid for feature information extraction. The method provides a new technical means for underwater target tracking and positioning, underwater acoustic communication Doppler compensation and marine environment dynamic monitoring, and particularly has an important application prospect in the fields of underwater unmanned cluster collaboration and the like.

The invention provides a blade lightning protection channel online test method and system based on a pulse current method, and belongs to the technical field of blade lightning protection detection.The method comprises the steps that a pulse waveform is generated through a pulse current generator to simulate lightning impulse, and the lightning impulse is injected into the surface of a lightning arrester of a blade lightning protection system; measuring channel currents at different positions of the surface of the lightning arrester in the length direction by using a distributed sensor; a high-voltage differential probe is used for collecting and measuring the waveform of an incident wave and the waveform of a reflected wave of an injection point; detecting blade surface potential distribution by using a capacitive coupling sensor; comparing the waveform of the incident wave, the waveform of the reflected wave and the theoretical waveform, determining a time domain reflection coefficient and a frequency domain impedance spectrum, and determining a fault type; after the fault type is determined, the fault point is positioned based on the channel current and the blade surface potential distribution, the lightning impulse is simulated through the pulse waveform, the lightning protection channel is further tested, shutdown is not needed, the testing efficiency of the blade lightning protection channel is effectively improved, and the power generation efficiency is ensured.

The invention discloses a cable fault ranging signal joint noise reduction method and system based on improved TVFEMD-CEMDF, and the method comprises the steps: injecting a low-voltage pulse at a detection point, and obtaining an original low-voltage pulse reflection wave signal x (t); secondly, performing time-varying filtering empirical mode decomposition (TVFEMD) on the original low-voltage pulse reflected wave signal x (t) to obtain N intrinsic mode components; the N IMFs are separated, and a noisy mode component p (t) and a non-noisy mode component q (t) are obtained; carrying out noise reduction processing on the noisy mode component p (t) by using combined form difference filtering CEMDF to obtain a de-noised mode component s (t); and finally, combining and reconstructing the de-noised modal component s (t) and the non-noised modal component q (t) to obtain a de-noised signal f (t). According to the technical scheme, a solution is provided for the problems of low signal-to-noise ratio and strong interference of detection signals in cable fault pre-positioning.

The invention relates to a near-surface defect positioning method based on a laser ultrasonic surface wave, which comprises the following steps of: extracting a defect tiny inverse signal and calculating reflection time delay by utilizing a high-frequency surface wave signal excited by laser through a wavenumber domain method to determine a defect position, and determining the burial depth of the defect through a reflection wave amplitude value of the defect; comprising the steps of S1, laser ultrasonic finite element simulation; s2, acquiring high-frequency laser ultrasonic signals; s3, direct wave and reflected wave extraction and time delay calculation; s4, determining defect space coordinates; and S5, determining the burial depth of the defect. The method makes full use of the advantages of high frequency and long propagation distance of surface waves, can effectively solve the problem of defect detection and positioning of the tested piece, can quickly detect the submillimeter defects, is high in positioning precision, and is suitable for positioning and detecting the submillimeter defects on the near surface of a structure.

The invention provides a linear dimension measurement method and device for the total length of a road guardrail stand column, and relates to the field of linear dimension measurement, the device is deployed on a detection vehicle, and comprises a control module, a ground penetrating radar measurement module, a 3D camera measurement module, a sensor module, a lower computer and an upper computer; according to the invention, accurate data acquisition is realized through multi-module cooperative control, and the lower computer is combined with the AI image recognition technology to realize accurate acquisition of contour data; the lower computer transmits radar original data (reflected waves and diffracted waves) and 3D contour data (column cap space coordinates) to the upper computer, the upper computer achieves data fusion through a hierarchical velocity model (time-depth conversion) and a coordinate system mapping algorithm (3D-road coordinate system), and the accuracy of the total length measurement error is greatly improved compared with that of single module detection. The method solves the problems of low efficiency, large destructiveness and poor accuracy of traditional manual detection, and has the advantages of method innovation and engineering landing.

The invention relates to the technical field of satellite altimetry, in particular to a height measurement method based on a feature-enhanced multi-base integrated re-tracking model, which is characterized in that the feature-enhanced multi-base integrated re-tracking model FMERM is constructed to optimize the position of a reflection waveform re-tracking point, and the FMERM model executes the following processing processes: 1, extracting input variable features by using PCA, and extracting the input variable features by using PCA; combining with an original input variable to form an enhanced feature set; secondly, optimizing the hyper-parameters of the XGBoost model by using a grid search method, so that the hyper-parameters of the XGBoost model are optimal; thirdly, utilizing the trained model to accurately calculate a re-tracking point normalization power value of the reflected signal waveform; fourthly, the sea surface height is inverted through the geometrical relationship and direct reflection signal time delay and atmospheric correction; an effective means is provided for solving the problem that a reflection waveform re-tracking method is inaccurate, and powerful support is provided for high-precision satellite-borne GNSS-R sea surface height measurement.

The invention relates to the technical field of reflected waves, in particular to a coal mine disaster comprehensive evaluation system based on three-component micro-motion detection, which comprises a frequency direction extraction module, a propagation included angle calculation module, a sensitive path identification module, a critical turning identification module and a structural disturbance mapping module. According to the method, the continuous sequence is formed in the space through the direction vector constructed through the main frequency value of the measuring point, an included angle screening strategy is used for eliminating incoherent direction sections, it is ensured that the path has trend consistency, the frequency amplitude difference value and symbol inversion are used for detecting a mutation point, and the response recognition capacity for directional changes is enhanced; the normalized frequency ratio is combined with a standard deviation and a difference value to carry out joint calculation so as to quantify a structure jump degree and improve the accuracy of reflex position expression, disaster boundary points form an image set, and a structure identification channel is established by taking a frequency direction as a principal line; and the spatial expression definition and precision are improved in the aspects of path aggregation, boundary precision, disaster recognition and partition and continuous structure drawing.

The invention relates to the field of terahertz technology and design and manufacturing of metasurface devices, in particular to a graphene-based electrically-controlled terahertz electromagnetic wave reconfigurable metasurface device which is configured in the mode that the conductivity of the reconfigurable metasurface device is controlled by adjusting the voltage applied to graphene in the reconfigurable metasurface device. The opening direction of the metal resonant ring on each unit cell in the reconfigurable metasurface device is actively controlled; and dynamically modulating the compensation phase of the incident light wave of the reconfigurable metasurface device to realize the dynamic regulation and control of the full phase of the reflected wave of the reconfigurable metasurface device. The conductivity and insulativity of graphene are controlled through voltage, the opening direction of the metal resonant ring is actively adjusted, and the compensation phase of incident light waves is dynamically modulated. Therefore, the metasurface can quickly carry out coding and function switching, the operation process is simplified, the production cost is reduced, the stability and reliability of equipment are improved, and the requirements of a high-performance photoelectric system and a communication technology are met.

The invention discloses a wind driven generator blade lightning conductor broken line point positioning method based on a radio frequency transformer, and relates to the field of wind driven generator blade lightning conductor broken line point positioning. A to-be-detected line is connected in series with the radio frequency transformer before being injected into traveling waves, and the change of traveling wave current is converted into the change of transformer output voltage; therefore, the output voltage of the radio frequency transformer is detected to judge the arrival time difference of the incident wave and the reflected wave, and then the breakpoint position is judged by multiplying the wave velocity by the time difference and dividing by 2. According to the wind driven generator blade lightning conductor breaking point positioning method based on the radio frequency transformer, the position of the lightning conductor breaking point can be efficiently, accurately, conveniently and flexibly detected at low cost, positioning measurement of disconnection of a multi-core wire part can be achieved, the specific positions of the breaking point and an abnormal point of the lightning conductor can be effectively determined, and the working efficiency is improved. After the positions of the broken line point and the abnormal point are determined, specific positions are repaired in a targeted manner, so that the cost for replacing the lightning conductor is saved.

A method for analysing a sample comprising a layer having a first interface and a second interface, the method comprising: Irradiating the sample with a pulse of terahertz radiation, said pulse comprising a plurality of frequencies in the range from 0.01 THz to 10 THz; Detecting radiation reflected from the sample to produce a sample waveform; Obtaining a first reflection waveform from the sample waveform, the first reflection waveform corresponding to the reflection from the first interface; Obtaining a second reflection waveform from the sample waveform, the second reflection waveform corresponding to the reflection from the second interface; Comparing the first reflection waveform with the second reflection wave-form to produce an estimate of a thickness and a complex refractive index of the layer; Producing a synthesised signal using the estimate of the thickness and complex refractive index; Varying at least one of the thickness and complex refractive index to reduce an error between the sample waveform and the synthesised signal; and Outputting the thickness of the layer.

The invention provides an unmanned aerial vehicle-based high-rise hyperbolic glass curtain wall automatic inspection method and system, and the system comprises an unmanned aerial vehicle, a data acquisition module and a controller. The data acquisition module is carried on the unmanned aerial vehicle and comprises an ultrasonic sensor array, an infrared thermal imager and an image acquisition module; the controller is used for performing time-frequency domain analysis on the reflected wave to obtain the signal intensity of the reflected wave; the controller performs temperature gradient calculation on the structural adhesive surface temperature distribution image to obtain temperature anomaly region features, obtains optical image textures according to the surface optical image, and outputs an inspection result according to the reflected wave signal intensity, the temperature anomaly region features and the optical image textures; generating an unmanned aerial vehicle flight path according to the three-dimensional model and the curvature parameter of the hyperbolic glass curtain wall, generating obstacle avoidance position information according to environment information set by the hyperbolic glass curtain wall, and updating the unmanned aerial vehicle flight path according to the obstacle avoidance position information; and controlling the unmanned aerial vehicle to automatically inspect the hyperbolic glass curtain wall according to the flight path of the unmanned aerial vehicle.

The invention discloses a method, a system, equipment and a medium based on a multi-composite ultrasonic penetration technology, and the method comprises the steps: generating high-frequency fundamental ultrasonic waves through a piezoelectric transducer array, and adjusting the frequency range to match the acoustic impedance characteristic of target soil; first, second and third harmonics are generated through the induction of a nonlinear medium in the fundamental wave propagation process, the phases of the harmonics are adjusted to realize coherent superposition, and the fundamental wave and the first, second and third harmonics are guided into a composite waveguide device for focusing and delay compensation to form a high-energy composite wave beam; a pulse interval is adjusted by adopting an intermittent emission strategy so as to inhibit energy attenuation in the soil; reflected wave spectrum components are monitored through an embedded acoustic sensor array, and driving parameters are dynamically adjusted; and residual ultrasonic energy is captured and fed back to a driving circuit to form a closed-loop energy utilization system. By integrating multi-order harmonic resonance and a dynamic frequency tuning technology, efficient transmission and deep penetration of ultrasonic energy in a complex medium are realized.

The invention discloses a VSP wellbore wave suppression method for improving U-Net based on physical constraints, which comprises the following steps: introducing apparent velocity constraints of an F-K transform domain, constructing physical constraint conditions, simultaneously realizing time sequence feature extraction and prediction of wellbore waves in combination with a GRU network, and learning a mapping relation between a noise image and a clean image by using the network so as to improve the suppression efficiency of the wellbore waves. The details and the structure of a noise image are accurately restored through a training network, the difference between a real de-noised image and network output is minimized so as to achieve the purpose of image de-noising, the model retains effective signals through a residual learning mechanism, and meanwhile precise suppression of shaft wave noise is achieved. The method provided by the invention can accurately identify and effectively suppress wellbore waves and reflected waves thereof in a complex VSP wave field, significantly improve the signal-to-noise ratio, reduce residual noise, improve data processing efficiency while improving data quality, provide technical support for high-precision seismic imaging under a complex geological condition, and have a wide application prospect. And meanwhile, a feasible solution is provided for popularization and application in an actual work area.

The invention relates to the field of geological detection of coal mine advanced detection drilling, in particular to an active and passive combined vibration detection method for drilling geology, which comprises the following steps of: recording the drilling depth during drilling while drilling in coal mine advanced detection drilling, and collecting a vibration signal generated by rock breaking of a drill bit as a passive detection signal; the lithology of a drilling point of the drill bit is analyzed according to the passive detection signal, and the lithology of a drilling section is determined according to the drilling depth; shock waves are excited in a gap controllable source excitation pipe of a continuous drill rod, reflected waves are collected to serve as active detection signals, and the geological breaking grade around a drilling section hole is analyzed according to the active detection signals; determining the collapse state of the drilling section based on the lithology of the drilling section and the geological fracture grade around the hole; and based on the collapse state, determining the risk levels of drill holding and drill breaking of the drill rod of the drilling section, and performing early warning according to the risk levels. According to the method, the drill holding and breaking conditions can be judged in real time in the drilling process, normal drilling construction is guaranteed, the drilling depth is increased, and the probability that drilling machine equipment is damaged is reduced.

The invention relates to the technical field of logging while drilling, and discloses a near-bit stratum detection method, system and device, electronic equipment and a medium, and the method comprises the steps: transmitting a seismic wave to a to-be-detected stratum in front of a drill bit through an underground vibroseis, and receiving a reflected wave signal of the to-be-detected stratum through a geophone; calculating the relative position of the stratum in front of the drill to the drill in real time according to the reflected wave signal; acquiring a first lithologic seismic wave characteristic parameter of the reflected wave signal and a second lithologic seismic wave characteristic parameter of a known typical stratum; matching the first lithologic characteristic wave characteristic parameter with the second lithologic seismic wave characteristic parameter, and determining the formation lithology and the geological structure of the formation to be detected; outputting the stratum information of the to-be-measured stratum including the distance data, the stratum lithology and the geological structure; the seismic waves are not affected by various complex geological environments, the stratum information of the stratum to be measured can be accurately obtained, the drilling risk is reduced, and the drilling efficiency and safety are improved.

The invention provides an aero-engine blade damage detection method based on an improved ultrasonic sparse reconstruction algorithm, and relates to the technical field of aero-engine damage detection positioning, and the method comprises the steps: S1, setting a sensor array and a detection region of a to-be-detected blade, and obtaining an actual measurement damage reflection signal dictionary through a sensor; s2, wave number distribution of a detection area is determined according to a variable thickness structure Lamb wave propagation model, signal reconstruction is carried out, and a theoretical damage reflection signal dictionary is obtained; s3, an aero-engine blade damage detection model is constructed, an improved sparse reconstruction algorithm is adopted to solve and optimize, and damage judgment is carried out; and S4, according to the pixel value distribution condition of the aero-engine blade detection area, generating an aero-engine blade damage detection image, and positioning a damage position. According to the method, the reflected wave amplitude information can be obtained from the array sensor signals, and the reflected wave amplitude information is compared with the reconstructed theoretical reflected signals, so that the damage condition of the aero-engine blade is identified and positioned.