103 results about "A wave amplitude" patented technology

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 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, in particular to a power grid overhead line traveling wave recording fusion fault positioning system, which comprises signal acquisition, traveling wave event stamp capturing, zero-sequence current data flow generation, fault triggering, zero-sequence integral comparison based on time reference to generate an activation instruction, and fault recording. The characteristic topology associates and fuses the traveling wave amplitude and the zero-sequence peak value, calculates a node attenuation rate and marks a breakpoint, and the positioning solution links a double-end timestamp and a wave velocity library according to the position of the breakpoint to output a fault coordinate. According to the invention, accurate locking of the fault moment is realized through synchronous acquisition of multi-source signals; a transient window defined by traveling wave triggering ensures complete capture of features; branch identification precision is improved through current vector fusion; parameters are automatically adjusted through dynamic wave velocity matching to improve positioning accuracy; time synchronization and wave velocity compensation eliminate the influence of line parameters.

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 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.

The invention provides a three-dimensional skin waviness fitting analysis method. The method comprises the following steps: performing boundary analysis on skin point cloud data obtained by laser measurement, performing interpolation sampling from the point cloud data according to a specified area and resolution to obtain point cloud coordinates which can reflect the real condition of the skin and are regularly arranged, performing bicubic spline surface least square approximation based on a sampling point set, and calculating the skin point cloud data according to the bicubic spline surface least square approximation. The method comprises the following steps: acquiring a reference curved surface reflecting the overall distribution trend of an analysis area, calculating distance deviation from a sampling point to the reference curved surface, carrying out filtering smoothing processing, forming a smooth deviation curved surface capable of reflecting the deviation condition of a measurement curved surface, extracting information such as wave crest and wave trough positions, wave amplitude, wavelength and slope in the deviation curved surface, and carrying out skin waviness characteristic analysis. According to the method, the tiny waviness characteristics of the irregular curvature surface of the aircraft can be extracted, the skin waviness distribution condition can be visually displayed, and the method has the advantages of being wide in applicability, small in error, high in reliability, low in time cost and the like.

The invention provides an aviation nacelle part waviness automatic detection and evaluation method, and belongs to the field of product production detection, and the method comprises the steps: carrying out the protocol scanning of part surface contour features, and obtaining the undistorted coordinate point discrete point cloud data of the actual surface contour; filtering the point cloud data; obtaining a piece of flattened deviation value discrete point cloud data; obtaining a flattened deviation value continuous curve by adopting a general standard curve reduction method; extracting waviness components, and obtaining a curve center line; obtaining a crest value and a trough value participating in calculation; and calculating the maximum wave amplitude, the waviness and the slope for evaluating the waviness by using the wave peak value and the wave trough value. According to the method, the relation between the minimum cut-off wavelength of the waviness and the sampling interval is stipulated, the undistorted reduction of the surface profile curve is ensured, the influence of non-waviness profile components in the digital evaluation of the waviness is eliminated through a combined calculation method, and the evaluation accuracy of the waviness of the aviation nacelle part is improved.

The invention relates to the technical field of construction quality evaluation, in particular to a dynamic compaction construction quality evaluation and analysis system which comprises the steps of collecting compaction vibration signals, screening out abnormal segments, extracting frequent fluctuation sections, counting peak value dense areas, recognizing impact concentration sections, tracking amplitude fluctuation changes, positioning energy accumulation areas and calculating the amplitude change rate. And the position of an inflection point is calibrated, a frequency change track is compared, a compaction state area is divided, and a compaction grade distribution map is generated. According to the method, amplitude change rate mutation fragments are eliminated, stable response sections are extracted, peak aggregation areas are divided according to time, impact concentration sections are identified, the amplitude continuous fluctuation trend is tracked, energy concentration areas are delimited, state turning nodes are positioned based on amplitude change rate comparison, and frequency span and fluctuation duration characteristics are combined. Compacting state areas are classified in a layered mode, and a compacting distribution structure is constructed.

The invention discloses a traveling wave triggering constant value adjusting method and device, a storage medium and computer equipment, relates to the technical field of traveling wave fault distance measurement, and mainly aims to solve the problem that key fault feature information of a power transmission line is lost due to a fixed triggering constant value of a non-contact traveling wave positioning device on a distributed monitoring node in the prior art. Comprising the steps of obtaining a power transmission line topological graph and a constant value list, and determining a double-end substation constant value line table corresponding to a to-be-adjusted power transmission line based on the constant value list and installation point position information in the power transmission line topological graph; when an initial instantaneous fault occurs, acquiring a traveling wave amplitude reported by each non-contact traveling wave positioning device on the to-be-adjusted power transmission line; determining a fault point interval position on the to-be-adjusted power transmission line based on the traveling wave amplitude and a double-end transformer substation constant value line table; and determining a triggering constant value of the to-be-adjusted non-contact traveling wave positioning device on the to-be-adjusted power transmission line according to the fault point interval position and the double-end transformer substation constant value line table.

The invention discloses a metering equipment remote calibration method and device, a medium and equipment. The method comprises the following steps: calculating a loss index according to current characteristics of an extracted current signal in a monitoring period, and determining a phase offset of each harmonic based on the loss index; constructing an environment gain coefficient according to the environment temperature and the environment humidity in the environment management period; constructing a current correction coefficient according to the fundamental wave amplitude of the current signal in the monitoring period and the environment gain coefficient; and correcting each harmonic amplitude in the next monitoring period according to the current correction coefficient, and correcting each harmonic phase in the next monitoring period according to the phase offset of each harmonic to obtain a calibration current in the next monitoring period.

The invention discloses a double-end traveling wave positioning optimization method, device and equipment and a readable storage medium. The positioning accuracy is improved from the three aspects of signal processing, fault detection and positioning calculation. Multi-level wavelet packet decomposition is carried out on an original traveling wave signal, a sub-band adaptive soft threshold is generated according to noise statistical characteristics, a traveling wave head signal with a high signal-to-noise ratio is reconstructed through filtering and inverse transformation, and the problem that signal integrity and noise suppression cannot be considered at the same time in a traditional method is solved. And time-frequency transformation and instantaneous energy envelope analysis are carried out on the reconstructed signal, after a correlation matrix and a sequence are generated, a lightweight time sequence model is input, and a fault triggering moment is output in combination with a constraint condition, so that the detection sensitivity of the weak high-resistance fault signal in a low signal-to-noise ratio environment is effectively improved, and the omission ratio is reduced. The coefficient compensation time difference is calculated according to the original time difference in combination with the wave amplitude value, and the positioning parameters are continuously corrected by dynamically updating the parameters and the coefficients, so that the limitation of the existing algorithm is overcome, and the positioning accuracy under a complex line is improved.

This invention discloses a method for calculating the vibration response of a delaminated composite laminate, belonging to the field of structural defect calculation and analysis. The method includes: dividing the composite laminate with delamination defects into delaminated and intact regions based on the damage condition; decoupling the delaminated regions dynamically; describing the vibration characteristics of each component in both the delaminated and intact regions using elastic waves based on elastic wave propagation theory, and establishing vibration state vector expressions for each region; determining the compatibility relationship based on the displacement continuity and internal force equilibrium conditions at the coupling point between the delaminated and intact regions, and establishing structural dynamic equilibrium equations in wave space based on the boundary conditions of the composite laminate; solving the structural dynamic equilibrium equations to obtain the amplitudes of elastic waves of each order; and calculating the vibration response of each region of the composite laminate based on elastic wave theory and amplitude calculation. This invention solves the problem of low computational efficiency in existing methods.

The invention discloses an intelligent research and judgment method and device for a distribution feeder fault based on traveling wave characteristics. In the operation process of the power distribution feeder line, forming time sequence original sampling data based on a unified time service reference, determining a traveling wave disturbance event and generating candidate traveling wave data; constructing a traveling wave time sequence consistency criterion based on the corresponding relationship between the traveling wave head first arrival time and the unified time service reference, and screening to obtain an effective traveling wave feature set; performing correlation analysis on the effective traveling wave feature set and historical operation feature data of the power distribution feeder to form a target traveling wave feature set; according to the time difference relation between the first arrival time of the wave head of the traveling wave in the target traveling wave feature set, the traveling wave propagation distance is calculated to determine the fault occurrence position, meanwhile, the polarity direction of the traveling wave and the amplitude variation of the traveling wave are integrated, the fault type and grounding characteristics are researched and judged, and a fault research and judgment result is output. According to the invention, the accuracy and reliability of power distribution feeder fault positioning and type identification can be effectively improved.

The invention relates to the technical field of permanent magnet synchronous motors, and discloses a permanent magnet synchronous motor turn-to-turn short circuit fault detection method and device, and the method comprises the steps: determining a discrete Fourier transform coefficient according to a carrier wave ratio; sampling the motor stator current for multiple times, and calculating a fundamental wave amplitude corresponding to the motor stator current by using discrete Fourier transform; and judging whether a turn-to-turn short circuit fault occurs or not according to the fundamental wave amplitude. According to the invention, fault detection is realized only through sampling and signal processing (for example, determining a DFT coefficient based on a carrier wave ratio and calculating a fundamental wave amplitude and an unbalance degree) on the stator current in an existing motor control system, and hardware equipment such as a resistance network and the like is not required to be additionally installed like a method based on a neutral-point voltage zero-sequence component, so that the hardware cost is prevented from being increased, and the fault detection efficiency is improved. And the system structure complexity and the subsequent maintenance difficulty are reduced, and the target of improving the reliability of the equipment is consistent.

The invention relates to the technical field of ocean resource development, in particular to a method for calculating vortex-induced vibration of a deep-sea mining riser under the action of internal waves. According to the method, velocity and acceleration distribution characteristics of a flow field are determined according to wave parameters such as amplitude and wavelength of ocean internal waves, and load input is provided for calculation of vortex-induced vibration of the deep-sea mining riser; the ocean internal wave flow field has remarkable particularity, is different from uniform flow and typical shear flow, and is unsteady non-uniform shear flow; based on the particularity of an ocean internal wave flow field, vortex-induced load distribution on a deep-sea mining riser under the action of a traditional wake flow vibrator model is obtained by improving the traditional wake flow vibrator model; according to the geometric nonlinear problem caused by the large slenderness ratio of the deep-sea mining super-long riser and the weak constraint characteristic of the deep-sea mining riser, the rigid body displacement and the elastic deformation of the riser are separately calculated by adopting a co-rotation coordinate method, so that the calculation efficiency is improved to meet the actual engineering requirements; the invention discloses a calculation method for vortex-induced vibration of a deep-sea mining riser under the action of ocean internal waves.

The invention provides a nuclear power plant thermal discharge dynamic change prediction analysis method, and relates to the technical field of data processing, and the method comprises the steps: collecting a temperature observation data set, extracting a temperature maximum value sequence and a temperature minimum value sequence in an equal-tide period, calculating a wave amplitude stable factor, extracting a plurality of trend inflection points of a temperature change first-order derivative curve, and calculating the temperature change first-order derivative curve. The method comprises the following steps: determining thermal expansion boundary candidate areas caused by thermal drainage, evaluating a time interval and amplitude difference between a lag response inflection point in each thermal expansion boundary candidate area and a previous dominant temperature rise point to obtain a thermal lag offset value, extracting a boundary sensitive area, performing multipoint communication fitting, determining a maximum space extrapolation boundary influenced by the thermal drainage effect, and performing thermal expansion on the maximum space extrapolation boundary. And carrying out trajectory tracking and change direction regression on the extrapolation boundaries at multiple different time points, and identifying a heat disturbance movement trend to obtain dynamic evolution data. The method can identify the diffusion trend of the warm discharged water and predict the temperature change.

The invention belongs to the field of material detection and evaluation, and discloses a phased array-critical refraction longitudinal wave-based plane stress detection method, which comprises the following steps: estimating a material sound velocity range, optimizing a phased array ultrasonic delay rule, obtaining a change curve of different excitation sound velocities and critical refraction longitudinal wave amplitudes, and extracting an optimal excitation sound velocity; critical refraction longitudinal waves are excited in the sample with the optimal excitation sound velocity, and processing such as interpolation and filtering is carried out on signals received by array elements of a receiving probe; obtaining the amplitude and sound time of critical refraction longitudinal waves, and calculating the sound velocity of the critical refraction longitudinal waves and the sound time difference of different array elements for receiving the critical refraction longitudinal waves; establishing the change relation of the critical refraction longitudinal wave sound velocity, the amplitude and the sound time difference along with the stress. According to the method, the critical refraction longitudinal wave acoustic time-stress relation in a traditional stress test method is improved into the critical refraction longitudinal wave acoustic time-stress-array element spacing relation, and the problems that in the traditional method, material adaptability is poor, acoustic time calculation stability is poor, and stress test reliability is low are effectively solved.

According to the multifunctional test method for simulating the erosion and erosion of the side slope, the wave making module is used for simulating waves with different energies, frequencies and amplitudes so as to test the requirements of different waves for simulating the erosion effect of the side slope; the influence of wave erosion on side slopes composed of different components is simulated by arranging a replaceable panel for simulating side slopes with different hardness or side slopes with different soil properties, the rebound energy of shore collision waves is reduced by arranging a wave dissipation module so as to avoid energy dissipation of simulated waves, and the wave dissipation module comprises an inverted triangular water retaining table provided with a soft water absorption piece. The buffer table is extremely small in gradient; various experiments such as scouring and erosion experiments at different angles, scouring and erosion experiments of waves with different energy and scouring and erosion experiments of slopes with different rock and mineral component structure types can be realized on one device, the device is simplified, energy is saved, and the experimental device has good application prospects in the aspects of environmental protection, geological disaster protection and the like. And the method has scientific research and engineering practical significance to a certain degree.

The invention discloses a distribution network traveling wave head analysis and fault location method and system based on edge calculation. The method comprises the steps that S1, terminal parameters are configured on a power distribution terminal; s2, monitoring a traveling wave signal and a power frequency electrical quantity of the distribution line in real time, and starting wave recording when a traveling wave amplitude exceeds a threshold value; s3, wave recording data are screened through the power frequency electrical quantity change and the traveling wave starting sequence; and S4, carrying out wave head detection on the fault initial traveling wave recording data, carrying out section determination on the fault so as to carry out double-end distance measurement, and then carrying out correction processing on the distance measurement result of the power distribution terminal located in the fault section based on the line section parameters. According to the method, a marginal distribution calculation mode is adopted, and fault identification, wave recording screening and positioning calculation capabilities are integrated on a power distribution terminal side, so that the data communication traffic and the calculation pressure of a master station are greatly reduced, real faults and interference wave recording can be effectively distinguished, and distance measurement errors caused by wave velocity differences in a mixed line in a traditional method are overcome.

The present invention discloses a probabilistic landslide tsunami disaster assessment method, device, and medium based on a logic tree, including: obtaining landslide data corresponding to the area to be detected; constructing a probabilistic landslide scenario set based on the logic tree method and deriving the geometric parameters of the landslide scenario; the first-level, second-level, third-level, and fourth-level nodes in the logic tree are landslide location, landslide volume, tsunami arrival point, and tsunami wave height; obtaining historical landslide tsunami records and submarine topography data of the area to be detected, and calculating the initial water level field of the tsunami wave through a first tsunami propagation numerical model according to the landslide location and volume in the probabilistic landslide scenario set; performing simulation using a second tsunami propagation numerical model based on the initial water level field of the tsunami wave to obtain the propagation path, maximum wave amplitude, and influence range of the tsunami; estimating the spatial probability of potential landslides in the area to be detected, the annual occurrence probability of landslides in each volume interval, and the probability that the maximum wave amplitude of the triggered tsunami does not exceed the tsunami wave height threshold at the tsunami arrival point.

The invention relates to the technical field of solid plate defect detection, in particular to a solid plate defect detection method based on Lamb wave end face echoes, which comprises the following steps: exciting and receiving wedge piezoelectric transducers are arranged on the same side of a solid plate, exciting and receiving a single-mode Lamb wave signal, and acquiring a multi-path signal comprising a direct wave, a side face echo and a defect reflection echo; by analyzing the difference between a direct wave and a side echo, a defect reflection signal is extracted, and by combining the time difference between the defect reflection signal and the side echo and the Lamb wave propagation speed, a geometric model is established, and the defect position is accurately calculated. By adjusting the position of a transducer, the time difference between a defect reflected wave and a direct wave is constant, a defect echo amplitude value is obtained under the equal propagation condition and compared with a standard test block amplitude value, a mapping relation between the amplitude value and the size is constructed, and accurate quantification of the defect size is achieved.

The invention relates to the field of non-invasive monitoring, and particularly provides a method for evaluating vascular elasticity through radial artery pulse waves. The method comprises the following steps that 1, radial artery pulse waves are obtained; step 2, preprocessing the radial artery pulse wave to obtain an average pulse period; 3, calculating a dominant wave angle based on the average pulse period; step 4, calculating pulse duration based on the average pulse period; step 5, calculating rise time based on the average pulse cycle; step 6, calculating a main wave amplitude based on the average pulse period; step 7, calculating a waveform area based on the average pulse period; and 8, establishing an evaluation model, inputting the dominant wave angle, the pulse duration, the rise time, the dominant wave amplitude and the waveform area into the evaluation model, and outputting a vascular elasticity predicted value by the evaluation model. According to the method, the accuracy of predicting the vascular elasticity is high, and the cost is low.

The application discloses a component fatigue micro-damage early identification method based on a nonlinear static component, and particularly relates to the technical field of material nondestructive testing and structural health monitoring, which comprises the following steps: arranging an excitation probe and a receiving probe on the surface of a component to be measured; selecting an excitation frequency based on a frequency dispersion curve and generating a Hanning window modulated wave; collecting a propagation response signal; extracting a static component amplitude A and a fundamental wave amplitude A through time-frequency processing; calculating a nonlinear static parameter beta=A / A²; further calculating a first derivative S(N) and a second derivative ΔS(N) of beta with respect to a fatigue loading cycle N; and identifying a dislocation dominant stage, a dislocation saturation or rearrangement stage, a micro-crack initiation stage and a macro-crack formation stage according to the first derivative S(N) and the second derivative ΔS(N). The application can be used for early stage identification of the evolution process of component fatigue micro-damage.

The invention discloses a method and a device for calculating the surge amplitude of a bifurcated channel. The method comprises the following steps: acquiring a surge wave of a surge before shunting at a bifurcated opening of the bifurcated channel; the method comprises the following steps: performing simplified fitting on a surge wave in front of a bifurcated opening to form an initial surge waveform; decomposing and dispersing the initial surge waveform into independent surge waves; on the basis of the initial surge waveform and the initial height of the independent surge wave, the amplitude of the independent surge wave at the bifurcated opening position at the moment t1 before collision reflection occurs in the shunting process is calculated; according to the movement and reflection path of each independent swell wave in the bifurcated mouth, the position of the independent swell wave at the moment t2 after collision reflection of the independent swell wave occurs is obtained; overlapping the amplitudes of the independent surge waves at the same position at the t2 moment to obtain the overlapped amplitude of the independent surge waves; and determining the superposed wave amplitude meeting a preset condition as the wave amplitude of the surge in the bifurcated channel. The invention provides a bifurcated channel amplitude calculation method.

The invention discloses a mutual inductor secondary circuit defect identification method and apparatus, a terminal device and a storage medium. The method comprises the steps of obtaining a secondary voltage waveform signal of a to-be-identified mutual inductor; performing Fourier transform according to the secondary voltage waveform signal to obtain a fundamental component and a harmonic component; judging whether a harmonic amplitude condition is met or not according to the harmonic component to obtain a first judgment result; according to the secondary voltage waveform signal, determining a corresponding waveform zero point and a wave crest; according to the secondary voltage waveform signal and the waveform zero point, judging whether a waveform abnormal condition is met or not, and obtaining a second judgment result; judging whether a fundamental wave amplitude condition is met or not according to the wave crest and the fundamental wave component to obtain a third judgment result; and obtaining a secondary circuit defect identification result of the mutual inductor to be identified according to the first judgment result, the second judgment result and the third judgment result. According to the invention, the monitoring efficiency of the power system is improved.

This invention discloses a method for calculating the vibration response of a delaminated composite laminate, belonging to the field of structural defect calculation and analysis. The method includes: dividing the composite laminate with delamination defects into delaminated and intact regions based on the damage condition; decoupling the delaminated regions dynamically; describing the vibration characteristics of each component in both the delaminated and intact regions using elastic waves based on elastic wave propagation theory, and establishing vibration state vector expressions for each region; determining the compatibility relationship based on the displacement continuity and internal force equilibrium conditions at the coupling point between the delaminated and intact regions, and establishing structural dynamic equilibrium equations in wave space based on the boundary conditions of the composite laminate; solving the structural dynamic equilibrium equations to obtain the amplitudes of elastic waves of each order; and calculating the vibration response of each region of the composite laminate based on elastic wave theory and amplitude calculation. This invention solves the problem of low computational efficiency in existing methods.

The invention discloses a pulse wave matching method, device and equipment for non-invasive blood pressure measurement. The method comprises the steps that pulse wave data on each pressure step are collected to obtain a typical pulse wave waveform in a rising-first and falling-second form; performing characteristic value extraction on the pulse waveform by adopting double sliding windows, and judging whether the characteristic values of the current pulse wave and the previous pulse wave are matched or not; the characteristic values comprise a pulse wave amplitude value, a processing signal peak value, a processing signal valley value and a processing signal peak-valley interval; if not, continuing to collect the pulse wave data and continuing to perform characteristic value matching, and if yes, collecting the pulse wave data on the next pressure step. According to the method, the pulse wave features are enhanced through double-window processing, and the influence of interference factors is effectively reduced while the matching judgment precision is improved in combination with the original waveform features.

The invention provides a method and a device for acquiring a grass-shaped wave amplitude value of a rail flaw detection car, and the method comprises the following steps: acquiring each frame of echo signal in a preset detection time gate interval in a detection channel of the rail flaw detection car, and storing each frame of echo signal; determining the maximum amplitude value of each frame of echo signal as a first maximum amplitude value of each frame of echo signal; counting again when the frame number of the stored echo signals reaches the detection frame number of the preset section every time, screening out the maximum amplitude value from the first maximum amplitude values of all frames of echo signals in each section, and determining the maximum amplitude value as the second maximum amplitude value of the section where the maximum amplitude value is located; when the detection section number of the rail flaw detection car reaches a preset detection section number, screening out the minimum amplitude value from the second maximum amplitude values of all sections, and determining the minimum amplitude value as the grass-shaped wave amplitude value of the detection channel of the rail flaw detection car; according to the method, the grass-shaped wave amplitude of the detection channel of the rail flaw detection car can be accurately obtained, the influence of human factors on gain adjustment is reduced, and data support is provided for rail detection.

The invention discloses a method for detecting impact damage of a plate-shaped structure based on elastic waves. The method comprises the steps that S1, a typical part is tested; and S2, real-time monitoring. According to the method, on one hand, an impact event detection process, an impact point location determination process and a damage evaluation process with elastic waves are obtained based on a simulation test, related characteristics formed when a plate structure is impacted are obtained in real time without manual intervention, and impact occurrence time, impact occurrence position, impact occurrence energy and damage evaluation can be obtained through comparison; on the other hand, impact point location information is accurately obtained based on a triangulation method, linear attenuation characteristics of elastic waves are obtained based on wave amplitude and relative distance detected by linearly arranged sensors, and a damage evaluation criterion is formed by combining simulation impact, so that health monitoring requirements of aviation, aerospace and important industrial structures are met; meanwhile, related human factors such as human negligence, fatigue errors and dangerous environments are eliminated, the labor cost is saved, the operation period is shortened, and the purpose of reducing the operation cost is achieved.

The present invention discloses a method for determining the equivalent design wave of a ship's wave load under level 6 sea conditions, relating to the field of ship structural safety. The method comprises: treating the hull as a variable-section beam, and for a ship at a constant speed, calculating the wave load transfer function at the hull beam section under different wave conditions, wherein the wave conditions include different wave direction angles and different circular frequencies of the incident wave; based on the wave load transfer function at the hull beam section, calculating the short-term predicted extreme values ​​of the wave load under different wave direction angles and different zero-crossing periods within the significant wave height range of level 6 sea conditions; selecting a maximum value from all the short-term predicted extreme values ​​of the wave load, and determining the equivalent design wave parameters of the wave load under level 6 sea conditions based on the maximum value. The equivalent design wave is a sinusoidal regular wave, and its parameters include wave amplitude, circular frequency, and wave direction. By converting the study of the load on the hull under random waves into the study of the hull load under regular waves, this method is of great significance for subsequent research on hull load levels and structural safety.