47 results about "Head wave" patented technology

The invention discloses a concrete crack detection method based on coupling of an infrared thermal field and a Rayleigh wave field, which comprises the following steps of: comprehensively scanning concrete in a target area by adopting an infrared thermal imaging method, and identifying the position of a concrete crack; calculating the depths of a superficial crack, a deep crack and a junction region crack; extracting Rayleigh wave amplitude attenuation characteristics to calculate crack width, and inverting a crack inclination angle based on time domain waveform head wave arrival time difference; superposing an infrared thermal imaging method detection result and a Rayleigh wave detection result, and constructing a three-dimensional visual crack model by adopting a linear interpolation algorithm; the crack position, the crack depth, the crack width, the crack inclination angle and the three-dimensional visual crack model are input, and a mass concrete crack detection report is generated. Through coupling detection of an infrared thermal field and a Rayleigh wave field, seamless connection of a shallow crack and a deep crack is achieved, a three-dimensional visual crack model is constructed, and the problems that a traditional method is low in efficiency, poor in precision and incomplete in coverage are solved.

The invention relates to the technical field of geological exploration, and discloses a thick loess highland coal field three-dimensional seismic exploration method, which comprises the following steps: S101, acquiring an artificial seismic source shot seismic record and superficial Rayleigh wave detector data; s102, performing grid division on the target area, and setting parameters to be inverted; s103, performing vertical ray path time estimation, multi-layer medium dispersion forward modeling and post-stack energy estimation; s104, generating a multi-target error function according to the head wave arrival time observation value, the Rayleigh wave observation dispersion curve, the theoretical ray path time, the phase velocity and the post-stack energy; s105, dividing the target region into three sub-regions, and performing differential evolution iteration until local convergence; s106, establishing a plurality of parallel annealing chains, setting chain temperatures, progressively decreasing the chain temperatures, optimizing to-be-inverted parameters, and outputting optimal to-be-inverted parameters; and S107, calculating the static correction time difference and the absorption compensation coefficient of each acquisition point. The coal seam structure imaging precision and the exploration data reliability under the complex earth surface condition are improved.

The invention relates to the technical field of ultrasonic measurement, and discloses an ultrasonic measurement head wave detection level online correction method and device, a medium and a product, in the correction method, by detecting level values AM1-AMn corresponding to wave crest amplitude values of a head wave and a plurality of receiving waves in a subsequent receiving sequence, delta AMm with the maximum absolute value in a quantity difference value delta AMn is obtained, and the maximum absolute value of delta AMm is obtained; and further, comparing the flight time difference delta Tn of two adjacent received waves with a first threshold value, and when the data exception proportion exceeds a second threshold value, further correcting to obtain a corrected head wave detection level FHLC. The design is reasonable, the metering precision can be improved, and the use cost of a user can be reduced.

The invention relates to the technical field of breakwaters, in particular to a breakwater embedded with an oscillating water column type wave energy power generation device adapting to tidal range variation, which comprises a breakwater body, a plurality of mounting grooves are formed in the head wave surface of the breakwater body and are respectively arranged at intervals in the horizontal direction, and a driving system is arranged in each mounting groove. The driving system is connected with an oscillating water column type wave energy power generation device, and the oscillating water column type wave energy power generation device is driven by the driving system to ascend and descend in the vertical direction. A plurality of oscillating water column type wave energy power generation devices are embedded in the head wave face of the breakwater body at intervals, and the heights and opening orientations of the oscillating water column type wave energy power generation devices are flexibly adjusted through the driving system so as to adapt to and be matched with tidal range changes and incoming wave direction changes of a service sea area; on the basis of maintaining stable mooring conditions in the harbor, energy absorption and capture of waves with different tide levels and incoming wave directions are achieved in an efficient mode, and the capture efficiency is improved to the maximum extent.

The invention relates to the technical field of disaster prevention and control engineering, discloses a glacial lake surge channel type energy dissipation and wave resistance tough structure and a layout method, and aims to solve the technical problems that the peak clipping capacity of head wave surge is insufficient, the structural stability depends on a rigid foundation, the energy clipping direction depends strongly and the like under the glacial lake working condition in an existing surge energy dissipation technology. The ice lake surge channel type energy dissipation and wave resistance tough structure comprises floating type wave dissipation elements, transverse array connecting cables and lateral restraining assemblies, the multiple floating type wave dissipation elements are connected in series through the transverse array connecting cables to form a transverse array, and the lateral restraining assemblies are arranged at the two ends of the transverse array connecting cables correspondingly. The floating type wave dissipation element is sequentially provided with an annular water-permeable flow guide energy dissipation crown, a water absorption-release elastic energy absorption array and a flexible air bag floating supporting assembly from top to bottom in the vertical direction, and a double-stone anchoring system is connected to the lower portion of the floating type wave dissipation element and comprises overhanging pumice stone, bottom anchoring stone and a vertical stroke limiting ring.

The present invention relates to a method for improving the wavy shape defects of the head of cold-rolled thin-gauge strip steel, comprising the steps of setting the roller shifting value according to the flatness, adjusting the frame load, and the like. The method for improving the wavy shape defects of the head of cold-rolled thin-gauge strip steel provided by the present invention is based on the existing plate shape control means of cold-rolled UCM equipment. By analyzing the influence of the intermediate roller shifting setting of the finished product frame on the plate shape control, a method for setting the intermediate roller shifting of the finished product frame for the wavy shape of the strip head is designed, as well as a method for resetting the load distribution if the plate shape control ability of the intermediate roller shifting is insufficient. Utilizing the method of the present invention, effective improvement measures can be implemented for the plate shape defects of the head of thin-gauge strip steel that plague production through manual intervention methods, which not only shortens the length of the thin-gauge strip steel with serious plate shape problems that needs to be sheared before entering the subsequent continuous annealing process, thereby improving the yield rate, but also improving the stability of rolling.

The invention discloses a tidal bore tide head line detection and segmentation method. According to the method, aiming at the problems of low tide line detection precision, weak generalization ability and large calculation overhead of an existing method, an instance segmentation method is innovatively used for detection. The method specifically comprises the following steps: introducing a C3k2ODConv module into a neck network, constructing a four-dimensional collaborative attention mechanism by using full-dimensional dynamic convolution, and enhancing the extraction and expression ability of a model to multi-scale features; a C2PSA module in a backbone network is replaced by a C2PSADA T module, and a DA attention mechanism and a feedforward network structure are introduced, so that the sensing and positioning capability of a key area in an image is improved; and meanwhile, a backbone network is replaced by a MobileNetV4 architecture, and a Fused-IB module and a UIB module are combined, so that the balance of model lightweight and deep semantic modeling is realized. Experiments prove that under the IoU threshold value of 50-95%, the average mask precision of the method reaches 68.2%, the model parameter quantity is 6.513 M, the reasoning speed is 25.2 ms / frame, the method is remarkably superior to an original model, detection precision and deployment efficiency are both considered, and the method is suitable for intelligent tidal bore monitoring in the complex environment.

The invention relates to the technical field of remote opening control, and discloses a power grid communication data processing system based on a remote communication unit, and the system comprises the steps: collecting the three-phase voltage traveling wave and temperature of a power grid according to a fixed time interval based on the remote communication unit in a safe operation time period of the power grid; determining a three-phase voltage traveling wave corresponding to the temperature T to extract a head wave zero-crossing density and a shoulder zero-crossing density at the temperature T, and determining a temperature wave baseline value corresponding to the temperature T; acquiring a voltage amplitude of the power grid, and triggering to acquire a fault three-phase voltage traveling wave of the power grid in response to voltage amplitude overrun; calculating a temperature wave monitoring value based on the fault three-phase voltage traveling wave; according to the temperature wave baseline value and the temperature wave monitoring value, carrying out correction processing on a preset reference speed to obtain an equivalent propagation speed; and calculating a correction fault distance according to the equivalent propagation speed and a timestamp corresponding to the head wave zero cross density of the fault three-phase voltage traveling wave, determining a fault section according to the fault distance, and carrying out opening control processing.

The invention discloses a float-type floating tunnel test device considering a ship impact variable head wave angle and immersion depth. The float-type floating tunnel test device comprises a tunnel pipe body in a segmental modular design, an end posture adjusting device, a float, a stand column, a ship impact simulation system and a measurement system. The end posture adjusting device can adjust the head wave angle and the immersion depth of the tunnel pipe body. A weak connecting assembly is arranged in the middle section of the stand column, and the weak connecting assembly is automatically disconnected when the impact load exceeds a threshold value. An impact device of the ship impact simulation system can adjust impact energy, position and angle; the measuring system collects the stress of the stand column and the tunnel pipe body, the acceleration of the tunnel pipe body and the displacement data of the buoy through a plurality of sensors. The device can simulate the dynamic response and failure process under multiple working conditions, and provides reliable test data support for design optimization and the like of the float-type floating tunnel.

The invention discloses a multi-wave-direction self-adaptive wave energy collecting device which comprises a floating box, a longitudinal energy collecting mechanism and a horizontal energy collecting mechanism, an energy conversion mechanism is arranged in the floating box, the longitudinal energy collecting mechanism comprises a floating body, a connecting rod is installed at the bottom of the floating body, and the floating body drives the connecting rod to reciprocate in the vertical direction along with fluctuation of waves; the horizontal energy collecting mechanism comprises a supporting platform and a head wave cylinder, the head wave cylinder is slidably installed on the supporting platform in the horizontal direction, a plurality of concave faces are arranged on the outer surface of the head wave cylinder, an inhaul cable is arranged on the head wave cylinder, and the concave faces bear the horizontal acting force of waves, synchronously drive the head wave cylinder to move in the same direction and pull the inhaul cable to move. One end of the inhaul cable is vertically downwards connected with the reset mechanism; reciprocating motion of the connecting rod and the inhaul cable is converted into rotating motion through the first input end and the second input end of the energy conversion mechanism, so that multi-wave-direction energy collection is achieved, wave energy is fully utilized, and the energy collection efficiency of the device is improved.

The invention discloses a concrete filled steel tube interface void detection method based on head and tail wave conjoint analysis. A plurality of piezoelectric sensors are uniformly arranged on the inner wall of a steel pipe, modulation pulse or sine wave signals are adopted to cyclically excite the piezoelectric sensors, and response signals of the opposite side and the corresponding adjacent sensors are collected. Under the assumption that both the steel pipe and the concrete are uniform media, the characteristic change of the head wave signal mainly reflects the interface state on the propagation path, and can be used for identifying the interface void of the area where the excitation or receiving sensor is located; as the tail wave signal contains multiple reflection and scattering components, the symmetrical path contrastive analysis is carried out on the tail wave signal, and the medium change of an indirect area between the sensors can be effectively sensed, so that the void condition of a corresponding position is judged. According to the method, quantitative recognition of the head wave on the path defect and high-sensitivity sensing of the tail wave on the change of the adjacent region are combined, so that a completely-covered void detection system is constructed, and the technical problem that global monitoring is difficult to realize by a traditional method is solved.

The utility model relates to a device for bonding and positioning lenses of an optical climbing frame, and belongs to the field of optical climbing frames. The device comprises a base which is provided with a first clamping groove, a second clamping groove, a first adjusting hole and a second adjusting hole; the climbing frame body is fixed in the first clamping groove and is provided with a second positioning groove; the positioning bracket is fixed on the base and is provided with an optical path channel and symmetrical rubber head wave bead jackscrews; the first adjusting support is fixed to the base and provided with a first thread pair, and the first thread pair is located in the first adjusting hole; the second adjusting support is fixed to the base and provided with a second thread pair, and the second thread pair is located in the second adjusting hole; when the two reflecting lenses are clamped in an area formed by combining the second positioning groove and the second clamping groove, one end of the first thread pair, one end of the second thread pair and one end of the rubber head wave bead jackscrew abut against the reflecting lenses. The device can be adjusted on the front side and the rear side of the two reflecting lenses, so that multi-degree-of-freedom fine adjustment is realized.

The invention discloses a concrete micro pile body integrity detection method based on an ultrasonic technology, and relates to the technical field of defect detection.The method comprises the steps that original waveform data of multiple depths in a concrete micro pile are obtained; according to smooth continuity of reflection extreme points of different depths in the original waveform data, a reflection extreme chain is constructed, and the reflection extreme points are waveform maximum values in the original waveform data; determining a suspected head wave extreme point in the reflection extreme points of different depths based on the matching optimization degree and the matching mutability of different reflection extreme points on the reflection extreme chain; based on the matching optimization degree of the suspected head wave extreme points of different depths, defect existence probabilities of different depths are calculated; and when the defect existence probability meets the preset condition, the depth position of the defect of the concrete micro pile is determined. The technical effect of improving the accuracy of defect identification is achieved.

The invention discloses an optimal phase matching wave source estimation method based on head wave statistics and norm constraint, and belongs to the field of signal processing. On the basis of statistical method wave source estimation, a Hilbert orthogonal component and a constant phase rotation mechanism are introduced to realize RMS energy retention type all-phase scanning wave source extraction, and the method specifically comprises the following steps: carrying out dynamic correction, first arrival alignment and interception on a fluctuation signal observation data set to obtain an initial time domain wave source under a minimum phase assumption; generating an adjoint component through Hilbert transformation, carrying out phase rotation at a step length of 1 degree, carrying out L2 norm energy maintenance after each rotation, and constructing a candidate wave source library with consistent energy; and keeping the amplitude of each candidate wave source consistent with the original wave source, then carrying out convolution with the measured reflection coefficient to generate a synthetic record, and carrying out cross-correlation analysis on the synthetic record and the actually measured signal record to determine the optimal phase and wave source. The method has the obvious advantages of keeping lower inversion residual error, better fitting of profile waveform and measurement data, higher inversion resolution and the like.

A marine propulsion system includes a propulsion device, an up-and-down movement sensor, and a controller configured or programmed to control driving of the propulsion device and perform a wave control including an attitude control to reduce an up-and-down attitude change of a hull by temporarily reducing a vessel speed based on a measurement result of the up-and-down movement sensor each time a marine vessel rides over a wave. The controller is configured or programmed to, in the wave control, perform the attitude control when it is determined that a wave condition is a head wave, and not perform the attitude control when it is determined that the wave condition is a following wave.

The present invention provides a method for determining the position of a received waveform of an ultrasonic flow metering device, aiming to improve the reliability of time-of-flight measurements and reduce flow metering errors. The method uses a variable threshold comparator to detect the head wave and tail wave, dynamically adjusting the threshold to adapt to different detection stages to ensure accurate identification of the echo signal. Combining zero-crossing time-of-flight measurement and pulse width difference comparison, the present invention can determine the tail wave position, infer the echo waveform position forward, and determine the accuracy of the zero-crossing point. In addition, by adjusting the phase of the transmitted ultrasonic signal to enhance the tail wave characteristics, the measurement accuracy is further improved. This method is applicable to flow measurement fields such as water meters, heat meters, and gas meters, and effectively reduces metering errors caused by signal fluctuations or interference.

The light-weight floating breakwater with the wave energy dissipation characteristic comprises a floating type main body structure, and the front side and the rear side of the floating type main body structure are each provided with a side box; the whole floating type main body structure is in an inverted-T shape, so that a step area is formed on each of the head wave face side and the back wave face side of the floating type main body structure, and the step areas are both located below the free liquid level. Wherein the step area on the wave facing surface side is used for inducing wave reflection, and the step area on the wave backing surface side is used for increasing wave breaking on the wave backing surface side; a water-permeable porous component is arranged in each step area of the floating type main body structure, and the water-permeable porous components are fixedly connected with the floating type main body structure and the side box; and the water-permeable porous part is used for dissipating wave energy. According to the floating breakwater, the wave energy on the wave facing side and the wave back side can be dissipated, and the wave absorbing efficiency of the floating breakwater can be effectively improved while the reflected wave energy is reduced.

According to the U-shaped network head wave arrival time extraction method, a U-shaped coding and decoding network is constructed, forward and backward spatial-temporal characteristics of sound wave signals are captured in combination with a bidirectional convolution long and short time memory module, the modeling capability of a head wave propagation rule is enhanced, in addition, a multi-scale attention module is introduced into the U-shaped coding and decoding network, head wave key characteristics are adaptively focused, and the head wave arrival time extraction efficiency is improved. Interference of environmental noise is effectively suppressed, and the problems of large parameter setting error and poor noise immunity caused by traditional artificial experience are solved.

The invention relates to the technical field of ocean engineering protection, in particular to an embedded seawall wave-resistant device which comprises at least one energy dissipation unit and a fixing structure, the energy dissipation unit is arranged on the head wave side of a seawall, the energy dissipation unit is constructed to be of an annular structure with a notch in the radial face and is provided with an opening in the axial direction, and the notch forms the head wave face; the fixing structure is fixed in the embankment; through the geometrical characteristics of the energy dissipation units, wave energy is converted into internal mutually-counteracted fluid motion, so that the purpose of actively and efficiently dissipating waves is achieved, and direct scouring of waves to the embankment body is relieved. According to the device, on-site construction installation and subsequent maintenance are facilitated, the arrangement scale and mode of the energy dissipation unit can be flexibly adjusted according to the protection requirement of a specific shoreline, and good adaptability and practicability are shown.

The invention relates to the technical field of wave energy power generation, in particular to a hydraulic and piezoelectric dual-coupling wave energy power generation device based on a flexible cavity, which comprises a hollow closed energy harvesting body and a hydraulic energy storage type power generation system, the head wave surface of the energy harvesting body is a flexible front wall, and the top of the energy harvesting body is a flexible top wall; the flexible front wall and the flexible top wall are both made of flexible piezoelectric materials, a hydraulic cylinder of the hydraulic energy storage type power generation system is arranged in an energy harvesting body, and a piston rod of the hydraulic cylinder is connected with the flexible front wall on the horizontal front face. Through the mutual coupling and synergistic effect of two power generation modes, the wave energy power generation device can actively adapt to different types of waves, the energy capture frequency band is widened, the overall power generation efficiency of the power generation device is kept higher and more stable under wider sea conditions, destructive wave impact force can be absorbed and converted into electric energy, and the power generation efficiency of the power generation device is improved. When extreme waves come, structural load shedding is achieved, the overall load of the device is reduced, the service life of the device is prolonged, and reliability is improved.

The invention discloses a method for remotely detecting a seabed buried target based on an earth sound head wave in a layered seabed, and relates to the field of underwater target detection. Earth sound head waves are incident at a critical angle and propagated along the sea bottom, the propagation speed is higher than that of direct waves propagated in water and sea surface seabed scattered waves, and the earth sound head waves reach the receiver before the direct waves. Based on the rapid propagation of the head wave, the target orientation can be inverted by using the delay inequality of the scattering echo of the seabed target under the excitation of the head wave to reach the receiver, and the remote detection and positioning of the seabed buried target are realized. The invention relates to a method for remotely detecting a seabed buried target and acquiring a target azimuth based on a rapid propagation characteristic of an earth sound head wave and by utilizing a sound scattering characteristic of the seabed buried target to the head wave.

The invention relates to an energy capture type wave-resistant device and a hydrodynamic performance analysis method thereof.The energy capture type wave-resistant device comprises M beach photovoltaic devices which are arranged in parallel from the head wave side to the back wave side, and each beach photovoltaic device in the M beach photovoltaic devices comprises a plurality of photovoltaic supports, vertical perforated wave-absorbing plates are arranged between the plurality of photovoltaic supports on the front N continuous tidal flat photovoltaic devices close to the wave facing side and between the plurality of photovoltaic supports on the front N continuous tidal flat photovoltaic devices close to the wave facing side, the draught depths of all the vertical perforated wave-absorbing plates in the same tidal flat photovoltaic device are the same, and the draught depths of the vertical perforated wave-absorbing plates on the front N tidal flat photovoltaic devices are gradually increased. Therefore, medium and long period waves can be reduced, the durability of the structure is improved, and the influence of engineering construction on the marine environment is reduced.

The invention relates to the technical field of ultrasonic waves, and particularly discloses a head wave determination method and device in ultrasonic flow metering, and the method comprises the steps: traversing and collecting ultrasonic waveform data, and recording values of all vertexes and corresponding coordinates in sequence; forward scanning is carried out from the maximum vertex, and a first vertex with the value smaller than a first threshold value is found and marked as a vertex i; when the value of the previous vertex, namely the vertex i-1, of the vertex i is smaller than a second threshold value and the coordinate spacing of the two vertexes is greater than or equal to the sum of the number of sampling points in the single period and 1, judging whether the value of the next vertex, namely the vertex i + 1, of the vertex i is smaller than a third threshold value or not; and if the value of the vertex i + 1 is smaller than a third threshold value, taking the coordinate of the vertex i + 1 as the arrival time of the head wave, otherwise, taking the coordinate of the vertex i as the arrival time of the head wave. According to the method, multiple threshold value judgment condition combinations are used, the stability of head wave position judgment is effectively improved, the wave hopping problem caused by interference is avoided, and the accuracy and stability of a flow measurement result are effectively improved.

The invention relates to a single-sensor two-dimensional impact positioning method and system of an integrated metasurface. The method comprises the following steps: acquiring a pre-prepared metasurface containing inverted T-shaped unit cells, forming an integrated sensor by utilizing the metasurface and a piezoelectric sensor, fixing the integrated sensor on a composite material plate, collecting a Lamb wave head wave signal generated by impacting a preset monitoring area, and labeling a corresponding two-dimensional impact position label; performing continuous wavelet transform on the Lamb wave head wave signal, extracting a wavelet coefficient of a preset low-frequency band, separating ridge slope features representing an X-direction impact position and multi-peak region range features representing a Y-direction impact position from the wavelet coefficient, and constructing a two-dimensional data matrix in combination with a two-dimensional impact position label to obtain a grayscale image sample; and training a pre-constructed convolutional neural network by using the normalized grayscale image sample, and realizing two-dimensional impact positioning by using the trained convolutional neural network. By adopting the method, the weight and complexity of the system can be obviously reduced, and the positioning robustness and accuracy can be improved at the same time.

The invention provides a nondestructive testing method for grouting defects at the end part of a prestressed duct, which comprises the following steps: exciting elastic waves by knocking an exposed steel strand of the duct, and arranging a sensor on a single measuring line on the surface of concrete to receive a signal; calculating an elastic wave refraction angle based on a Snell law, and determining a theoretical head wave amplitude inflection point position in combination with the thickness of a cement paste layer and the thickness of a concrete layer; and judging the existence of the end defect and quantifying the defect length by analyzing the difference between the actual inflection point and the theoretical inflection point of the actually measured normalized head wave amplitude curve. If the difference value is greater than 10cm, the defect exists, and the length of the defect is equal to the difference value. The structure does not need to be damaged, the excitation position is fixed, and the detection efficiency is high; noise is effectively suppressed by adopting band-pass filtering, and the method is suitable for metal / plastic corrugated pipes; defects are directly quantified through inflection point position differences, operation is easy and convenient, precision is reliable, and the industrial problem that end defects cannot be specially detected in the prior art is solved.

The invention provides a well cementation quality detection method, which is used for detecting the cementation degree of a current casing and a rock stratum to generate a detection result, and comprises the following steps: acquiring a group of sound wave signals transmitted through the current casing and the rock stratum; converting the group of sound wave signals into corresponding envelope waves; wherein the envelope wave refers to amplitude detection of a group of sound wave signals; extracting an envelope wave peak value from the envelope wave, evaluating the cementing degree of the current casing and the rock stratum based on the envelope wave peak value, and generating a detection result of the cementing degree of the current casing and the rock stratum. According to the method, one group of sound wave signals is used, comprehensive evaluation is carried out through one group of sound wave signals in the face of the high-speed rock stratum, detection is not carried out through sound wave head waves, the influence degree of the high-speed rock stratum on sound waves can be effectively reduced, and the accuracy of a detection result is improved.

The invention discloses a method for controlling a head wave peak value of a high-capacity energy storage type test power supply, which comprises the following steps of: applying a standard sinusoidal pulse width modulation (SPWM) pulse signal to each sub-power unit of a power unit, and outputting a test voltage after the output voltages of the sub-units are cascaded and superposed; collecting test waveforms of a first preset number of pulse signals, judging whether the peak value exceeds a preset threshold value or not, and continuing if the peak value does not exceed the preset threshold value; determining an adjustment proportion based on the peak difference, and calculating a DC component adjustment value in combination with a standard SPWM pulse signal amplitude; the number is segmented according to the time slices, and the direct-current component is gradually decreased to the last time slice of the last pulse signal of the first preset number to be 0 one time slice by one time slice; superposing the progressively decreased direct current component to the corresponding pulse signal to obtain a new SPWM pulse signal; and providing the first wave peak value to the sub-power unit to enable the first wave peak value to exceed a threshold value. According to the invention, the first wave peak value of the output test voltage is effectively improved to a preset threshold value, and the instantaneous peak tolerance test requirements of equipment such as a transformer and switch equipment are met.

The invention relates to a single-end fault positioning method suitable for a multi-branch power distribution network, which belongs to the technical field of fault positioning of a power distribution line, and comprises the following steps of: 1, calibrating a fault reflection head wave arrival time tf1 through a reflection wave arrival time sequence after injecting a signal; step 2, performing time-frequency transformation on the pure reflected wave signal by adopting WVD to obtain a time-energy curve of the main frequency f0 of the head wave reflected by the fault point, determining the central position and the interval range of a time-frequency window Wi, and constructing an energy distribution vector of each reflected wave in sequence by sliding the time-frequency area Wi; 3, introducing cosine similarity to carry out quantitative evaluation on similarity between energy distribution vectors of the fault reflection head wave and other reflection waves, and screening fault characteristic reflection waves through a similarity threshold value delta; 4, calculating the relative position of a fault point through the propagation time difference, and judging a fault branch in combination with the topology of the power distribution network.

The invention discloses a high-frequency guided wave detection method for crack defects of an anchoring anchor rod, belongs to the field of nondestructive testing of anchor rods, and aims to carry out nondestructive testing on defect degrees and positions of the anchoring anchor rod and construct a high-frequency ultrasonic guided wave nondestructive testing system. A frequency scanning method is adopted for carrying out high-frequency guided wave detection on an anchor rod-resin-surrounding rock three-layer anchoring anchor rod test piece, the echo signal state and distribution characteristics are analyzed, the optimal excitation frequency, system gain and head wave width are optimized, nondestructive detection is carried out on anchoring anchor rods with different defect degrees, and the purpose of detecting the defect degrees and defect positions is achieved. According to the high-frequency ultrasonic guided wave nondestructive testing method and the built testing system, nondestructive testing can be conducted on a large-size three-layer anchoring anchor rod structure, and an efficient and reliable method is provided for nondestructive testing of anchoring anchor rods in actual engineering. The constructed ultrasonic guided wave nondestructive testing system can detect the defect degree and position of the anchoring anchor rod, and the defect position detection error is smaller than or equal to 2%.