54 results about "A wave amplitude" patented technology

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.

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 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 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 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 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 invention provides an anti-interference echo signal detection method and system for an ultrasonic flowmeter, and relates to the technical field of signal processing. Comprising the following steps: identifying wave crest positions and wave trough positions of a plurality of continuous waves in an ultrasonic echo signal, and determining time and amplitudes of the wave crest positions and the wave trough positions; calculating wave amplitudes of the plurality of waves, judging whether the wave amplitudes of the plurality of waves are all greater than an amplitude threshold, and if so, meeting the amplitude requirement; calculating wave crest frequencies and wave trough frequencies of the plurality of waves, judging whether differences between the wave crest frequencies and the wave trough frequencies of the plurality of waves and the frequency of the driving signal are within a set frequency width range or not, and if so, meeting the frequency requirement; the ultrasonic echo signals meeting the amplitude requirement and the frequency requirement at the same time serve as effective echo signals. According to the method, the echo signal is identified and positioned by taking the echo frequency and the echo amplitude as judgment conditions, so that the situations of signal failure and the like caused by abnormal deformation of the signal are reduced.

The invention discloses a three-phase coupled falling type dangerous rock surge amplitude prediction method which comprises the following steps: when a dangerous rock impacts a water body to form a cavitation bubble, the cavitation bubble is subjected to three stages of development, contraction and closing, and data of the thickness a of the dangerous rock, the length Lpot of the cavitation bubble and the water depth hw are acquired; the speed v0 and the initial potential energy Ec of the dangerous rock at the moment of making contact with the water surface and the initial kinetic energy Ek0 of the dangerous rock at the moment of impacting the water surface are calculated; iteratively solving the movement speed in all subsequent movement time, and establishing a speed-time relation curve after the dangerous rock enters water; according to the speed at any moment, the corresponding cavitation bubble diameter, the change rate and the change rule of the cavitation bubble potential energy along with time are obtained, and then the potential energy maximum value of the cavitation bubble above the closed point is obtained; the surge wave energy conversion rate is solved according to the maximum cavitation bubble potential energy value, and finally the maximum surge amplitude is solved. The method has the advantages that the energy conversion mechanism of the gas-phase substance in the wave making process is quantified by introducing the cavitation kinetic model, and the wave amplitude prediction precision is remarkably improved.

The invention provides an experimental determination method for an annular flow pattern interface shear force, and belongs to the technical field of gas well drainage and mining processes, the method comprises the following steps: carrying out a visual physical simulation experiment, observing an annular flow pattern flow state, taking a base membrane area as a liquid membrane main body bearing part, uniformly distributing ripples with micron-order wave amplitudes on the surface, and taking the ripples with micron-order wave amplitudes as a liquid membrane main body bearing part; a disturbance wave area shows three-dimensional wave structure characteristics, a liquid film structure under different flow parameters is a complex combination of disturbance waves and ripples, the disturbance wave area is divided into a base film area and the disturbance wave area, and for the base film area, a sectional roughness expression is constructed with the critical liquid film thickness as a threshold value; for a disturbance wave area, Weber number, Froude number, pipe diameter and liquid phase Reynolds number expressions are introduced, and an experimental determination method of the annular flow pattern interface shear force is provided through weighted solution. Therefore, the calculation method is high in actuarial performance, and a theoretical basis is provided for optimization design of the drainage and mining process.

The present application relates to photovoltaic power generation technical field, disclose a kind of pulse width modulation method and inverter, comprising the following steps: obtaining three-phase initial, DPWM modulation wave;First common-mode modulation wave is generated;According to the reference modulation wave of first common-mode modulation wave amplitude and three-phase initial modulation wave;Whether three-phase reference modulation wave amplitude is in the set range is compared: yes then first common-mode modulation wave amplitude is multiplied with correction coefficient and obtains second common-mode modulation wave amplitude;Otherwise first common-mode modulation wave amplitude is used as second common-mode modulation wave amplitude.Second common-mode modulation wave is generated.The superposition obtains three-phase output modulation wave.The present application combines the clamping state of the modulation wave of three-phase DPWM of three-phase inverter, the first common-mode modulation wave is smoothly handled, effectively eliminates the high-frequency harmonic component of first common-mode modulation wave, and then determines three-phase output modulation wave according to the second common-mode modulation wave and the three-phase initial modulation wave, thereby improve the system stability of three-phase inverter.

The application belongs to the technical field of marine resource development, and is a calculation method for vortex-induced vibration of a deep-sea mining riser under the action of internal waves. According to wave parameters such as the wave amplitude and wavelength of the marine internal waves, the velocity and acceleration distribution characteristics of the flow field are determined to provide load input for the calculation of vortex-induced vibration of the deep-sea mining riser. The marine internal wave flow field has significant particularity, which is different from uniform flow and typical shear flow, and is a kind of non-uniform shear flow. Based on the particularity of the marine internal wave flow field, the vortex-induced load distribution on the deep-sea mining riser under the action of the improved traditional wake oscillator model is obtained. In view of the geometric nonlinearity problem caused by the large slenderness ratio of the deep-sea mining super-long riser and the weak constraint characteristics of the deep-sea mining riser, the rigid body displacement and elastic deformation of the riser are separated and calculated by using the co-rotational coordinate method, so as to improve the calculation efficiency to meet the actual engineering requirements, and form the calculation method for vortex-induced vibration of the deep-sea mining riser under the action of the marine internal waves.

To estimate the amplitude of a wave without performing integration for acceleration time series data indicating a change over time of a measured value of the acceleration in the vertical direction applied to a floating matter floating on the water due to a vertical motion of the water surface.SOLUTION: Acceleration acquisition means 111 acquires acceleration time series data from a terminal 2 through an interface 13. Smoothing means 112 reads out the acceleration time series data acquired by the acceleration acquisition means 111 and stored in a memory 12 and smooths a change over time in a predetermined period of the acceleration indicated by the acceleration time series data. Period specification means 113 specifies, by using the acceleration time series data, a period of a change over time of the acceleration in the vertical direction applied to a floating matter J floating on the water due to a vertical motion of the water surface. Amplitude estimation means 114 estimates the amplitude of a wave according to the period specified by the period specification means 113, in accordance with the relationship between the amplitude of the wave and the period of the change over time of the acceleration.SELECTED DRAWING: Figure 4

This invention discloses a dynamic start-stop and pressure stabilization control method for water pumps based on operating condition identification, relating to the fields of mechatronics and automation control technology. The method includes the following steps: S1, outputting the predicted arrival time node of the reflected wave; S2, outputting operating condition attribute labels; S3, parsing the operating condition attribute labels; S4, inputting the dynamic fluctuation characteristics and graph topology space into an improved DCRNN model, introducing a bandgap filter based on acoustic impedance constraints and a resonant coupling diffusion mechanism to perform frequency domain filtering suppression and impedance matching coupling; S5, outputting a dynamic start-stop delay reference; S6, outputting the primary water hammer wave; S7, outputting the error compensation coefficient; S8, performing adaptive linkage correction on the dynamic start-stop delay reference and wave amplitude evolution reference. This invention overcomes the limitations of traditional methods, such as static threshold fixation, semantic simplicity, and neglect of spatiotemporal coupling topological constraints, providing an efficient solution for proactive defense against transient flow in fluid pipeline networks.

The present application 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 echo, which comprises the following steps: arranging excitation and receiving wedge piezoelectric transducers on the same side of the solid plate, exciting and receiving single mode Lamb wave signals, obtaining multi-path signals containing direct wave, side echo and defect reflection echo, enhancing the identification ability of boundary and local defects, extracting defect reflection signals by analyzing the difference between direct wave and side echo, combining the time difference between the defect reflection signals and the side echo and the Lamb wave propagation speed, establishing a geometric model and accurately calculating the defect position. By adjusting the transducer position to make the time difference between the defect reflection wave and the direct wave constant, the defect echo amplitude is obtained under the condition of equal propagation, compared with the standard test block amplitude, the mapping relationship between amplitude and size is constructed, and the accurate quantification of defect size is realized.

The application discloses a kind of crack variable-thickness plate structure vibration response semi-analytical calculation method, belong to engineering structure defect calculation and analysis field, including: crack variable-thickness plate structure is divided into crack region and crack-free region, the vibration of crack region is described using finite element, and crack-free region is described using analytical wave;Crack-free region is dispersed into multiple sections along the thickness variation direction, and the vibration of each section is described using analytical wave;Based on the compatibility relationship of different sections when coupling and the structure boundary condition, the structure dynamic equilibrium equation under wave space is established;Solving structure dynamic equilibrium equation obtains the wave amplitude of each order elastic wave, and obtains the vibration response of each section in crack variable-thickness plate structure based on elastic wave theory.The application solves the problem of low efficiency of existing method.

The utility model belongs to aviation composite material workpiece nondestructive testing technical field discloses a contrast test block positioning structure. The contrast test block positioning structure includes detection groove body and the module assembly of leaning. Detection groove body is configured to accommodate coupling agent and contrast test block, the module assembly of leaning includes two symmetrical positioning structures, two positioning structures can be installed in the inside of detection groove body, and abut to the inner wall of detection groove body, when contrast test block is set up between two positioning structures, coupling agent can submerge the bottom surface of contrast test block. Detection groove body and the module assembly of leaning mutually cooperate, so that when contrast test block is set up between two positioning structures, coupling agent can submerge the bottom surface of contrast test block, ensure that there is no gap between contrast test block and positioning structure, thereby eliminate the situation that contrast test block bottom wave amplitude is reduced and waveform is deformed in the porosity curve collection process of contact type pulse reflection method due to the flow of coupling agent.

The application discloses a power transmission and distribution line grounding state recognition method, device, equipment and medium, and belongs to the field of power transmission and distribution line state detection. The method is: collecting the feedback voltage signal of the to-be-tested line when a non-power frequency current signal is injected; calculating a spectrum distortion weight index reflecting the ratio of induced harmonic to injected main wave amplitude value according to the spectrum data of the feedback voltage signal; performing multi-scale decomposition on the feedback voltage signal to obtain energy data corresponding to each decomposition scale, and calculating wavelet energy spectrum entropy according to the energy data; calculating the similarity between the feature vector constituted by the spectrum distortion weight index and the wavelet energy spectrum entropy and a plurality of pre-constructed state vectors; wherein the state vector is constructed through electromagnetic transient simulation, and each state vector corresponds to a grounding state; and taking the grounding state corresponding to the first state vector with the largest similarity as the grounding state of the to-be-tested line. The application can improve the accuracy of grounding state recognition of the to-be-tested line.

The application discloses a distribution network traveling wave wave head analysis and fault positioning method and system based on edge calculation, and the method comprises the following steps: S1, configuring terminal parameters on a distribution terminal; S2, monitoring traveling wave signals and power frequency electrical quantities of a distribution line in real time, and starting wave recording when the traveling wave amplitude exceeds a threshold value; S3, screening the wave recording data through the power frequency electrical quantity change and the traveling wave starting sequence; S4, detecting the wave head of the initial traveling wave wave recording data of the fault, positioning the fault, and then correcting the positioning results of the distribution terminal located in the fault section based on the line section parameters. The application adopts the edge distribution calculation mode, integrates the fault identification, wave recording screening and positioning calculation capacity on the distribution terminal side, greatly reduces the data communication amount and the calculation pressure of the main station, can effectively distinguish the real fault and the interference wave recording, and overcomes the positioning error caused by the wave speed difference in the mixed line in the traditional method.

This invention discloses an internal wave prediction method based on wall sensors. First, it acquires parameters such as the thickness of the density cascade layer, the location of the density cascade center, the density values ​​of the upper and lower layers, wave amplitude, and buoyancy frequency. These parameters are then used in a numerical solver to solve the DJL equations, constructing the initial flow field for the internal wave. Calculation settings are configured in Fluent. Sensor measurement points are placed on the wall of the vehicle and data is transmitted. In Fluent, the pressure and wall shear stress data at the nodes are stored in ASCII format. A convolutional neural network is used to convert the input data into a dual-channel image format, with one channel storing pressure data and the other storing wall shear stress data. The coordinates and amplitude of the vehicle relative to the wave trough are used as labels. Finally, the convolutional neural network is trained, enabling the prediction of internal waves. This invention enables real-time prediction of internal isolated waves using sensors, which has significant engineering application value for ensuring the safe operation of vehicles.

The application relates to the technical field of metrology, in particular to a method, device and equipment for distinguishing a stable region and a transition region of quantum voltage steps, wherein the method comprises the following steps: making a PJVS output a staircase wave voltage signal according to a sine rule, grouping sampling data on all quantum voltage steps of each period sine wave, and performing sine wave fitting, then performing time domain single frequency decomposition on the fitted sine wave voltage to obtain a fundamental wave amplitude; taking a preset position of the quantum voltage step as a starting point, searching for minimum values of uncertainties of the fundamental wave amplitude from positive and negative directions respectively, and dividing a sampling data interval between sampling points corresponding to the minimum uncertainties at two ends into the stable region, so as to complete the division of the stable region and the transition region on the quantum voltage step. Thus, the problems of confusion in distinguishing the stable region and the transition region, poor robustness and low measurement accuracy in related technologies are solved.

This invention provides a system and method for simulating seismic waves excited by explosive sources. It selects initial parameters of the explosive source based on various characteristics of explosive sources, simulates and predicts the explosion process, and establishes a cavity expansion model for the source. Based on this model, it establishes the relationship between the initial parameters of the explosive source and the amplitude-frequency characteristics of the initial seismic wave, obtaining a model of the amplitude-frequency relationship between the initial parameters. Using a viscoelastic medium model, it analyzes the absorption and attenuation of the seismic wave spectrum during propagation in the medium, establishing a characteristic model of the seismic wave field excited by the explosive source. Based on this model, it establishes a complete process model of the explosive-source-excited seismic wave, from the action of the explosive source to the formation and propagation of the seismic wave. It couples the computational processes to obtain the characteristic parameters of the explosive source throughout the entire process and the amplitude-frequency characteristics of the seismic wave during propagation. Finally, it performs quantitative calculations and simulations of the near and far field states of the seismic wave excited by the explosive source.

The embodiment of the application relates to an intelligent voltage protection system and method under complex power grid conditions, and belongs to the technical field of power distribution and power supply systems. The method steps comprise: collecting three-phase voltage signals, extracting fundamental wave amplitudes, determining voltage sag events, recording sag depth and duration and generating a feature vector; obtaining a hierarchical voltage protection setting value table, comparing the feature vector with the setting value table, estimating fault point distance and identifying a fault section, and issuing a trip command or maintaining a monitoring state to a circuit breaker in a preset time delay sequence. The embodiment of the application can effectively distinguish the severity of voltage sag events of different degrees, improve the selectivity and accuracy of protection action, minimize the power outage range, guarantee the power supply continuity of non-fault sections, and realize the leap of voltage protection from simple threshold judgment to intelligent hierarchical decision.