432 results about "Propagation time" patented technology

The invention discloses a power transformer partial discharge positioning method based on multi-sensor array fusion, and the method comprises the following steps: S1, selecting a sensor installation point, and laying a multi-sensor array structure; s2, partial discharge signals of the three types of sensors are collected, and primary signal processing is carried out; s3, calculating propagation time differences between the reference channel and other channels by adopting a generalized cross-correlation weighting algorithm, and generating a time difference matrix; s4, constructing a TDOA model in combination with the layout coordinates and the time difference matrix, and solving three-dimensional initial coordinates of a power supply; s5, establishing a structure correction model, compensating the path deviation, and outputting corrected positioning coordinates; s6, calculating an error and generating a confidence score; s7, mapping a positioning result to the three-dimensional model and generating an image; and S8, writing the positioning information into a database for filing management. According to the method, the multi-frequency sensor and the path correction model are fused, and high-precision three-dimensional positioning of partial discharge of the transformer is realized.

The invention relates to the technical field of water pump control, and discloses a water pump energy-saving optimization control method and system. The method comprises the steps of obtaining water pump outlet pressure, pipe network tail end flow and water pump motor power monitoring signals; calculating a flow-pressure propagation time compensation coefficient and a pressure fluctuation compensation value to eliminate the influence of signal propagation lag and amplitude fluctuation; extracting an operation condition feature vector by combining the motor power frequency domain energy distribution feature and the pressure fluctuation compensation value, and matching the operation condition feature vector with an energy-saving parameter mapping rule base to generate an energy-saving parameter combination; correcting a water pump efficiency reference curve in real time based on the combination, outputting an efficiency attenuation factor, and generating a control deviation value in combination with a target water supply demand; according to the control deviation value, the water pump rotating speed adjusting quantity and a start-stop priority sequence are calculated, and the priority sequence is optimized in combination with historical operation data to generate a machine number control instruction; and finally synthesizing a control signal to drive an execution mechanism.

The invention relates to the technical field of power transformer state monitoring, and discloses a main transformer winding temperature rise on-line monitoring method and system, and the method comprises the steps: obtaining the calibration flight time of ultrasonic waves through an acoustic sensor array disposed on the outer wall of an oil tank in a quasi-isothermal state of a transformer; calculating a structure additional time delay which is caused by an internal fixed structure and does not change along with the temperature, and establishing an acoustic fingerprint for the transformer; during on-line monitoring, oil way net propagation time reflecting temperature change of the insulating oil is obtained from on-line flight time measured in real time; and then, based on the net propagation time of the oil way, an acoustic tomography algorithm is adopted to reconstruct internal two-dimensional or three-dimensional temperature field distribution, and the winding hot-spot temperature is finally and accurately calculated in combination with the real-time load current. According to the invention, through the acoustic fingerprint correction technology, the measurement interference of an internal fixed structure is eliminated, and non-intrusive, high-precision and visual online monitoring of the winding hot-spot temperature is realized.

The invention discloses a non-aligned spatio-temporal data driven multi-sensor fusion method and system, and the method comprises the steps: building a matching measurement function through collecting radar point cloud density and visual image texture, and constructing a synchronous gradient field through employing a space depth change parameter and a visual motion contour, and determining a data synchronization standard; detecting a time sequence abnormal accumulation area based on a synchronization standard, and identifying an abnormal starting point and propagation time delay through a backtracking track to form an asynchronous sensor coordinate table; iMU angle increment and sensor response delay are collected, and sampling imbalance information is generated through time domain matching of an attitude switching signal and a data collection inflection point; performing association mapping on the asynchronous coordinate table and the sampling imbalance information to generate a feature offset, determining a matching core area, and creating a hierarchical calibration sequence; performing internal and external source difference identification analysis on the calibration sequence to obtain an offset transfer speed to form an offset coupling factor; and a fusion enhancement region is determined based on the offset coupling factor, and high-precision multi-source data fusion is realized through cascade analysis and gain coefficient coding.

The invention relates to the technical field of water supply pipeline detection, and discloses an underground water supply pipeline health grade evaluation and risk prediction method, which comprises the following steps: sensor arrangement: arranging a flow sensor, a pressure sensor and a sonic sensor at key positions of an underground water supply pipeline; and data acquisition: acquiring signals of the sensor in real time through a data acquisition module, wherein the signals comprise flow, pressure and sound wave signals. Preprocessing the data: carrying out preprocessing such as denoising and normalization on the collected signals; and multi-source data fusion: inputting flow, pressure and sound wave signals into a deep neural network model, and performing feature extraction and fusion analysis. And health level assessment: assessing the health level of the pipeline based on the output result of the deep neural network model. And risk prediction: predicting abnormal working conditions possibly occurring in the future and risk levels of the abnormal working conditions by analyzing the current pipeline state and historical data. And abnormal positioning: accurately positioning an abnormal position in combination with the propagation time of the sensor signal and a positioning model of the deep neural network.

The invention relates to the technical field of underwater detection, and discloses an underwater comprehensive detection system. The system collects multi-dimensional acoustic data including sound wave reflection intensity, propagation time delay and frequency dispersion characteristics of a target water area through an underwater sonar array; dividing the detection area into a plurality of layered units according to a water attenuation coefficient and a substrate reflection characteristic of the acoustic data, and extracting an environment intrinsic parameter of each layered unit; constructing an acoustic propagation path model based on the environmental intrinsic parameters, and generating adaptive filtering parameters in combination with a preset noise suppression strategy; calling sonar array hardware configuration data, matching filtering parameters with an array beam forming mode, and calculating a detection sensitivity threshold value of each layered unit; and integrating the sensitivity threshold and the acoustic data, generating a three-dimensional acoustic characteristic spectrum of the target water area, and marking the space coordinates and confidence level of the abnormal area. The system can improve the comprehensiveness and accuracy of underwater detection, and meets the requirement of high-precision detection.

The invention relates to the technical field of safety monitoring, and provides an oil and gas pipeline leakage monitoring method and system, a medium and equipment, and the method comprises the steps: obtaining a leakage vibration signal of each measurement point of an oil and gas pipeline, and extracting a time domain feature, a frequency domain feature, a spatial-temporal feature and an initial distance from a leakage point to a starting end of an optical fiber; performing cross-correlation analysis on the leakage vibration signals of the adjacent measuring points to obtain a propagation time difference and a cross-correlation coefficient, and calculating a correction distance from the leakage point to the starting end of the optical fiber; if the leakage point is in the spiral section, calibrating the correction distance to obtain a calibration distance; calculating the difference value between the initial distance from the leakage point to the optical fiber starting end and the corrected distance to obtain a preliminary positioning error value; and based on the time domain feature, the frequency domain feature and the spatial-temporal feature, in combination with a cross correlation coefficient, a calibration distance, an amplitude enhancement coefficient and a preliminary positioning error value, obtaining a leakage medium type through a medium identification model. The method gives consideration to the positioning efficiency and precision, and greatly improves the accuracy and robustness of a leakage medium type recognition result.

The invention relates to an ultrasonic phased array full-focusing imaging method for acoustic wave multi-path propagation compensation of a layered composite material, which is characterized by comprising the following steps of: arranging an ultrasonic phased array probe with N array elements on a composite material piece to be detected, obtaining complete echo data by taking each array element as a transmitting array element and taking all array elements as receiving array elements in sequence in a full-matrix acquisition mode; a two-dimensional pixel grid is established in an imaging area, a Monte-Carlo perturbation mechanism used for representing the acoustic wave propagation uncertainty in the layered composite material is introduced into a propagation model for each emission array element-receiving array element-pixel point combination, and the acoustic beam emission direction, the propagation path and the equivalent acoustic velocity are subjected to random perturbation, so that the acoustic wave propagation uncertainty in the layered composite material can be represented. Generating a plurality of equivalent sound wave propagation paths, calculating two-way propagation time of each path, and performing weighted statistics on energy contributions of different paths according to array element sound beam directivity to obtain equivalent propagation time delays of pixel points; and performing delay correction on a full-matrix echo signal by using the equivalent propagation time delay, and performing coherent superposition on signals of all transmitting-receiving array element combinations to realize dynamic focusing of a full-pixel grid, and finally reconstructing an ultrasonic full-focusing imaging image with high resolution and high signal-to-noise ratio. The time delay error caused by propagation path deviation and sound velocity non-uniformity in the layered composite material can be effectively compensated, the focusing precision and spatial resolution of full-focusing imaging are improved, meanwhile, an existing TFM imaging frame does not need to be changed, and the method has good engineering implementability and popularization and application value.

The invention relates to the technical field of fault diagnosis, and discloses a cable fault diagnosis method, system and terminal, and the method comprises the steps: applying a broadband excitation signal to a target cable, so as to excite the target cable to generate a first response signal; extracting multi-dimensional time-frequency features of the first response signal after adaptive wavelet threshold denoising, and matching a fault template of a preset cable reference model according to energy distribution features in the multi-dimensional time-frequency features; determining a fault area in a fault template corresponding to the target cable according to the propagation time and the propagation speed of the first response signal; applying the narrowband excitation signal to a fault area of the target cable to obtain an impedance spectrum; the resonant frequency point based on the impedance frequency spectrum and the corresponding impedance amplitude value are compared with a typical fault mode in a fault feature database, and the fault type and the fault position of the target cable are obtained; generating a diagnosis report of the target cable according to the fault type and the fault position; the cable fault diagnosis accuracy can be improved.

A method for measuring gas temperature and flow velocity through sound waves comprises a sound wave transmitting end, a sound wave receiving end, a signal processing end, a central calculation end and a visualization module, the sound wave transmitting end is used for transmitting sound wave signals and capturing echo signals, and the sound wave receiving end is used for receiving the sound wave signals and transmitting the echo signals; the signal processing end is used for preprocessing sound wave signals and calculating propagation time of sound waves, the central calculation end is used for calculating gas temperature and gas flow velocity, and the visual module is used for displaying a real-time change curve of the gas temperature and the gas flow velocity. The invention provides an improved acoustic multi-path flow field real-time separation algorithm for signal processing, provides an improved multi-path flow field coupling acoustic temperature measurement algorithm for gas temperature calculation, provides an improved multi-path temperature flow coupling dynamic speed measurement algorithm for gas flow velocity calculation, and provides a better scheme for a method for measuring the gas temperature and flow velocity through sound waves.

The invention relates to the technical field of motor state monitoring, in particular to a motor state monitoring method and system based on data driving, and the method comprises the following steps: synchronously collecting a motor voltage signal amplitude time domain sample and a motor current signal amplitude time domain sample for a power frequency period in a motor operation state; and calculating an instantaneous phase difference between each corresponding sample point to obtain an instantaneous phase difference original data stream of the motor. The method comprises the following steps: synchronously acquiring voltage and current amplitudes during operation of a motor in real time, and calculating an instantaneous phase difference between the two amplitudes to obtain an electromagnetic state original data stream; further executing high-pass filtering and performing spectral analysis to filter interference signals and low-frequency trend influences, and improving the recognition precision and robustness of instantaneous phase difference jitter features; meanwhile, voltage pulses are actively injected into the winding, echo signals are collected, and rapid capturing and positioning of the abnormal state of the winding are achieved through propagation time delay calculation and impedance characteristic construction.

The invention discloses a geological disaster monitoring and early warning system based on a rock-soil body micro-seismic sensing network, particularly relates to the technical field of geological disaster early warning, and is used for solving the problems of insufficient positioning precision and poor early warning reliability caused by neglecting rock stratum heterogeneity in an existing seismic source positioning method. The method comprises the following steps: constructing a three-dimensional heterogeneous rock stratum model containing fractures and faults by acquiring geological exploration data of a monitored area, simulating a distortion propagation path of micro-seismic waves in an anisotropic medium, and generating a waveform feature library; extracting time-frequency domain energy distribution of an actual signal, matching the time-frequency domain energy distribution with the feature library, and dynamically correcting equivalent wave velocity field parameters; calculating a propagation time difference matrix in combination with sensor coordinates and a corrected wave velocity field, and constructing a nonlinear equation set taking wave velocity deviation as a constraint to solve seismic source space coordinates; and finally, generating a dynamic early warning signal based on the distribution relationship between the seismic source and the rock stratum model. And the seismic source positioning precision and the early warning accuracy in a complex rock mass environment are remarkably improved.

The invention provides a GIS insulation defect evaluation method and device and electronic equipment, and relates to the field of data processing. According to the method, a cross-modal synchronous data stream formed by an ultrahigh frequency sensor and a mechanical vibration sensor on a GIS (Geographic Information System) is obtained, event slicing is firstly carried out, multi-dimensional features are extracted, and candidate events are screened in combination with a sparse labeling library; and generating a propagation time delay window and a path priority table by using a three-dimensional geometric model, completing cross-modal pairing and time registration, outputting a registration result, performing array manifold sparse reconstruction separation, and eliminating multipath interference to obtain purification components. And constructing a cross-modal event chain graph based on the purification components, executing spatial positioning and physical quantity inversion under the constraint of the chain graph, and finally generating a defect evaluation report in combination with a historical labeling result, thereby realizing high-precision detection and evaluation of GIS insulation defects. By implementing the technical scheme provided by the invention, the accuracy of insulation defect evaluation can be improved.

According to the passive underwater cooperative positioning system and method provided by the invention, an intelligent signal processing and analysis module in the system receives a target underwater sound backscattering signal and a target environment parameter output by an environment adaptive feedback module, and then a path identification result and a positioning result are obtained by combining an identification model; obtaining a sound velocity correction value and a propagation time correction value based on the target environment parameters and a sound velocity correction model so as to obtain the moving speed of the target object; the cooperative positioning calculation module predicts the positioning information of the next moment based on the historical positioning information and the positioning information of the current moment; the environment self-adaptive feedback module receives the underwater sound backscattering signals generated by the multi-mode signal acquisition module and the acquired environment parameters, and transmits the underwater sound backscattering signals and the acquired environment parameters to the intelligent signal processing and analysis module as target underwater sound backscattering signals and target environment parameters; and the dynamic adjustment module is also used for dynamically adjusting the state parameters of the underwater acoustic backscattering signals and the environmental parameters so as to obtain new target underwater acoustic backscattering signals and target environmental parameters.

The invention belongs to the technical field of power equipment signal processing, and particularly relates to a multi-channel signal reverberation suppression method based on phase weighted cross-correlation optimization, which comprises the following steps: S1, acquiring an original multi-channel time domain signal matrix; s2, estimating propagation time delay of each channel relative to the reference channel; s3, enabling all channels to realize time domain alignment in a direct sound main energy section; s4, processing to obtain a multi-channel time-frequency domain signal; s5, performing reverberation suppression by adopting a WPE algorithm to obtain a multi-channel time-frequency domain signal after reverberation removal; before the WPE algorithm is executed, through a Bayesian optimization method based on a Gaussian process, a prediction order and prediction delay parameter combination enabling the SI-SNR of the multi-channel dereverberation signal to be maximum is searched, and the prediction order and prediction delay parameter combination is applied to the WPE algorithm; s6, reconstructing the multi-channel time-frequency domain signal after reverberation removal into a time domain signal; and S7, calculating a normalization coefficient, and performing amplitude scaling. According to the method, the dereverberation ultrasonic signal with high fidelity, high consistency and high robustness can be obtained in a complex reverberation environment.

The invention belongs to the technical field of underwater measurement, and discloses a test probe underwater depth automatic positioning method and system, and the method comprises the steps: collecting an absolute water pressure value of a current underwater environment, and carrying out the calculation of a hydrostatic pressure value through combining with water surface reference air pressure data; meanwhile, acoustic signals from the water surface base station are received, response is returned, and the round-trip propagation time of sound waves in the water body is measured and obtained; collecting water body temperature data and salinity change data, estimating density information of the current water body, and converting a hydrostatic pressure value into a pressure depth value; calculating an average sound wave propagation speed by adopting an empirical sound velocity model, and calculating an acoustic depth value of the probe in combination with back-and-forth propagation time of sound waves in the water body; the depth positioning precision and stability of the underwater probe in a complex environment are effectively improved, and high-reliability and high-precision underwater depth automatic positioning is realized.

The invention provides a coal storage temperature detection method and device, electronic equipment and a storage medium. An ultrasonic generator is arranged on the upper portion of the ground of a coal yard and transmits an ultrasonic signal to a coal pile; an ultrasonic signal receiver is arranged at the lower part of a ceiling of a coal yard to receive an ultrasonic signal penetrating through a coal pile and obtain propagation time and energy attenuation information of the ultrasonic signal, and temperature distribution of each area in the coal pile can be calculated based on the propagation time and the energy attenuation information in combination with a preset corresponding relation between ultrasonic sound velocity and temperature; and when the temperature of any area of the coal pile exceeds the preset coal ignition point threshold value, an alarm signal is triggered and position information of the corresponding high-temperature area is output, so that the problems that in the prior art, due to the fact that heat cannot be dissipated in time after coal is stacked, temperature distribution conditions of the middle and lower layers of the coal seam are difficult to master and early warning cannot be performed in time are solved. The spontaneous combustion of the coal is easily caused.

The invention relates to the technical field of multi-mode ultrasonic flow nonlinear error compensation scheme design, in particular to a multi-mode ultrasonic flow nonlinear error compensation method and system. The method comprises the following steps: acquiring propagation time data of different sound wave paths through a multi-ultrasonic transducer array; extracting a multi-modal characteristic parameter reflecting the nonlinear characteristic of the fluid; abnormal types such as bubble interference, solid impurities or turbulence are identified based on the characteristic parameters; calling a preset compensation model which is matched abnormally to generate a dynamic correction parameter; and fusing the parameter and the path weight coefficient to reconstruct an accurate flow value. The system is correspondingly provided with a sensing module, a feature extraction module, an interference identification module, a dynamic compensation module and a flow reconstruction module. The measuring bottleneck of a traditional flowmeter in complex fluid is broken through, and through the synergistic effect of interference type recognition and a dynamic compensation model, the measuring precision, the environmental adaptability and the long-term stability under the complex working condition are remarkably improved.

The invention provides a high-precision three-dimensional ultrasonic wind speed measurement method and device, the method is applied to an ultrasonic transducer array, a plurality of transducers in the transducer array are arranged according to a non-orthogonal structure to form a plurality of acoustic measurement paths, and the specific steps are as follows: acquiring ultrasonic signals collected on the plurality of acoustic measurement paths; for each acoustic measurement path, determining a downwind and upwind propagation time difference of ultrasonic waves on the path based on cross-correlation operation and sine wave fitting; and calculating a three-dimensional wind speed vector based on the geometrical relationship of each acoustic measurement path and the corresponding propagation time difference, thereby achieving the technical effects of remarkably improving the anti-interference capability, greatly improving the measurement precision, remarkably improving the calculation speed, optimizing the spatial symmetry, enhancing the environmental adaptability and improving the measurement robustness.

The invention discloses an anti-electromagnetic interference coding method and system for a pulse sequence of an ultrasonic flowmeter, and relates to the technical field of industrial measurement. The method comprises the following steps that a pulse sequence of the ultrasonic flowmeter in the working process is obtained; the pulse sequence is processed, and the electromagnetic interference type is identified through machine learning; constructing a final feature matrix based on feature enhancement of an acoustic-electric coupling factor; a dynamic coding generation strategy: receiving an original pulse sequence output by the TDC chip, and selecting a coding scheme according to the current interference type; and error feedback calibration is carried out by adopting a bidirectional propagation time correction formula. Real-time interference classification is carried out through machine learning, and FPGA hardware completes level coding switching, so that a signal spectrum dynamically avoids an interference frequency band, and the anti-electromagnetic interference capability of the ultrasonic flowmeter is improved.

The invention relates to the technical field of Beidou reference correction, in particular to a Beidou-based space-time reference dynamic correction method. The method comprises the following steps: firstly, collecting Beidou multi-frequency-point observation data, and preprocessing by adopting a Kalman filtering algorithm; then, based on the preprocessed data, a base station network time synchronization mechanism is established by using Beidou satellite signal propagation time difference, spatial reference data of different base stations are integrated through a multi-sensor fusion algorithm and a least square method, and smoothing processing is performed by using a spatial interpolation algorithm; thirdly, selecting an optimal baseline combination based on a space-time synchronization result, constructing a difference observation equation of a Beidou multi-frequency carrier phase and a pseudo range, fixing integer ambiguity by adopting an LAMBDA algorithm, and establishing a unified space-time reference model; and finally, resolving the clock error of the high-precision receiver by utilizing the double-difference integer ambiguity constraint, generating a correction parameter, and dynamically adjusting and updating the correction parameter by adopting a model algorithm. According to the invention, high-precision dynamic correction of the space-time reference is realized.

The invention discloses a ring main unit cable line fault positioning system and method based on traveling wave intelligent sensing, and relates to the technical field of ring main unit cable line fault positioning, and the method comprises the following steps: arranging a traveling wave sensor at a position corresponding to a cable connecting plug or a solid-sealed polar pole in a ring main unit; an initial correction stage is carried out, a known electrical event is triggered on a cable in actual operation, the propagation time of a traveling wave signal between the two ends is measured, and the wave velocity of the traveling wave is actually measured on site and dynamically updated in combination with the known cable length; the method comprises the following steps: executing initial correction under different operation conditions, collecting corresponding data of working conditions and wave velocities, constructing a self-adaptive model of the wave velocities and working condition parameters, and when a fault occurs, dynamically predicting the wave velocities based on the constructed model according to current working condition parameters monitored in real time; and on the basis of the identified wave head timestamp, constructing an overdetermined equation set and solving an optimal fault position, so that the cable line fault positioning of the ring main unit is realized.

The invention provides an underground pipe gallery environment intelligent monitoring method and system based on multi-mode sensing, and relates to the technical field of monitoring, and the method comprises the steps: obtaining acoustics, pressure and temperature data collected by multiple types of sensors, carrying out the time domain and frequency domain feature extraction, carrying out the matching with a leakage feature mode library, determining a candidate section, and extracting a sound wave propagation time delay inequality; and carrying out constraint solution on the time difference positioning equation set by combining the pressure drop gradient and the temperature abnormal distribution, and determining and outputting the space coordinates of the leakage point. According to the invention, accurate positioning of pipe gallery leakage is realized, and the sensitivity and reliability of the monitoring system are improved.

The invention relates to the technical field of communication, in particular to a high-precision measurement method for radial velocity of a shallow sea underwater acoustic target based on ray sound field reconstruction, which comprises the following steps of: establishing a three-path propagation model comprising direct arrival, water surface reflection and seabed reflection, and constructing a joint representation equation comprising channel impulse response and target motion parameters by the path propagation model; according to the method, a space-time joint representation model of multipath sound rays is constructed, and the limitation of a traditional single-path model is broken through by quantifying the coupling relation between propagation time delay and Doppler frequency shift of different paths; the development provides a new technical means for underwater target tracking and positioning, underwater acoustic communication Doppler compensation and marine environment dynamic monitoring, and especially has an important application prospect in the fields of underwater unmanned cluster collaboration and the like.

The invention provides a cable fault early warning method and system, a storage medium and a program product, and relates to the technical field of electrical variable measurement. And calculating the absolute value of the amplitude difference under adjacent sampling points, comparing the absolute value with the relative change value, and screening out signal parts which are really changed and possibly predict faults. Waveform segments in a preset time window before and after the traveling wave starting point are extracted to generate a front-end feature segment and a rear-end feature segment; carrying out discretization, Fourier transform and other operations on the characteristic fragments, converting a complex waveform of a time domain into a frequency domain for analysis, calculating time delay by searching a peak position in a time domain cross-correlation function sequence through correlation calculation of the frequency domain, and comparing with a traveling wave theoretical propagation time difference calculated by detecting the length of a cable between groups; if the difference value is greater than the threshold value, the fault hidden danger is judged and early warning is triggered, the cable section with the fault hidden danger is positioned, the fault repair efficiency is improved, and the normal power supply order and the normal operation of the power utilization unit are ensured.

The invention relates to a method for calibrating an ultrasonic flowmeter, which is coupled to a pipe (1), for measuring a flow velocity or a volumetric flow rate of a fluid by means of two ultrasonic transducers (2, 3) spaced apart from one another, wherein the main directions of the ultrasonic transducers (2, 3) are oriented at an angle to one another in a symmetrical V shape. The aim of the invention is to provide an improved method which allows the ultrasonic flowmeter to be installed on a pipe with minimal effort, even by untrained personnel, without the accuracy of the measurement being impaired. For this purpose, the invention proposes the following steps: - ascertaining the propagation speed of an ultrasonic signal propagating through the pipe wall as a surface wave; - ascertaining the wall thickness of the pipe by determining the propagation time of an ultrasonic signal through the pipe wall; - ascertaining the inner diameter of the pipe by deriving it from the value of the adjusted angle and the distance of the ultrasonic transducers, - adjusting the angle to the ascertained pipe geometry by means of at least one motorized actuating drive (5) which sets the angle and an electronic calibration device (6) which interacts with the actuating drive (5).

The invention discloses a steel rail stress measuring system based on electromagnetic ultrasonic orthogonal transverse waves. The steel rail stress measuring system comprises an electromagnetic ultrasonic probe and a signal processing unit, the electromagnetic ultrasonic probe is configured to be an orthogonal coil group with orthogonal axes, the electromagnetic ultrasonic probe generates eddy current under the excitation of alternating current and generates a first transverse wave and a second transverse wave on the steel rail, the propagation directions of the first transverse wave and the second transverse wave are both vertically downward from the center of a rail head of the steel rail, the vibration direction of the first transverse wave is the length direction of the steel rail, and the vibration direction of the second transverse wave is the length direction of the steel rail; the vibration direction of the second transverse wave is the width direction of the steel rail head, and the vibration direction of the first transverse wave and the vibration direction of the second transverse wave are perpendicular to each other to form an orthogonal relation; and the signal processing unit is used for synchronously receiving echo signals of the first transverse wave and the second transverse wave, calculating a propagation time difference between the first transverse wave in the length vibration direction and the second transverse wave in the width vibration direction, and evaluating the axial stress of the steel rail according to the propagation time difference between the first transverse wave and the second transverse wave.

The invention relates to the technical field of stress detection, in particular to an acoustic nondestructive testing method and system for bolt tightness, and the method comprises the following steps: transmitting longitudinal waves and transverse waves to a bolt without pretightening force, and calculating the propagation time ratio M of the longitudinal waves and the transverse waves in the bolt without pretightening force under the environment temperature change condition; transmitting longitudinal waves and transverse waves to the bolt with the pre-tightening force, and calculating the propagation time TP and TS of the longitudinal waves and the transverse waves in the bolt with the pre-tightening force under the environment temperature change condition; and calculating the stress sigma of the bolt according to the propagation time ratio M of the longitudinal wave and the transverse wave in the bolt without the pre-tightening force, the propagation time TP and TS of the longitudinal wave and the transverse wave in the bolt with the pre-tightening force and the effective clamping distance of the bolt under the environment temperature change condition. According to the invention, signal interference caused by temperature change and processing errors can be overcome, and the detection precision of the bolt stress is obviously improved.

The invention particularly relates to a deep sea reliable sound path long baseline robust positioning method based on iterative equivalent sound velocity correction, which comprises the following steps: firstly, selecting a coordinate origin, and delimiting a positioning area by taking the coordinate origin as a center; a sonar receiving array is distributed to a proper position, a hydroacoustics numerical calculation ray model is utilized to establish a sound field model according to data such as a sound velocity profile, a target sound source depth and a horizontal distance range, and an equivalent sound velocity table is obtained. Then, inputting an initial equivalent sound velocity vector and an initial relative propagation time vector, and obtaining initial target position estimation by using a hyperbolic intersection method; next, the equivalent sound velocity and the target position are updated through iteration, and an adaptive adjustment item is introduced, so that the convergence and robustness of the algorithm are improved; and finally, judging whether iteration is terminated or not by utilizing a maximum likelihood error function. The method combines the hyperbolic intersection method to efficiently solve and adaptively adjust items, is high in positioning precision, is high in calculation efficiency, and is suitable for underwater real-time high-precision positioning tasks.

The invention relates to the technical field of ocean engineering, in particular to a wind power single pile local scouring real-time detection method based on multi-frequency acoustic tomography, which comprises the following steps: S1, annularly arranging an acoustic sensor array on the section above the water surface of a pile body; s2, transmitting multi-frequency sound wave signals including low-frequency penetrating waves and high-frequency surface waves; s3, scattered wave signals reflected by the pile-seabed interface are collected, and low-frequency scattered waves and high-frequency scattered waves corresponding to the frequency in S2 are separated; s4, constructing a mud layer penetration acoustic tomography matrix and a surface topography acoustic tomography matrix; s5, three-dimensional data fusion is carried out, and a three-dimensional image of the scouring state of the seabed around the pile is generated; and S6, a scouring pit is positioned according to a sound wave propagation time delay sudden change area in the three-dimensional image of the scouring state. According to the method, the scouring state of the seabed around the wind power single pile foundation can be accurately monitored by combining the multi-frequency acoustic tomography technology and time delay abrupt change area detection.