87 results about "Body waves" patented technology

The invention provides a side slope crack passive source seismic wave imaging method, which adopts a multi-wave multi-component seismograph to simultaneously collect a plurality of seismic wave signals on three components, including surface waves, body waves and the like. According to the design, the richness of the data is remarkably improved, so that the physical characteristics of various seismic wave signals can be comprehensively utilized for inversion analysis in data processing. Through combined processing and constraint of different wave types, the problem of multiplicity of solutions in geophysical inversion can be effectively reduced, and the stability and reliability of a result are improved. In addition, due to acquisition of multi-component data, imaging is more comprehensive, and particularly, the method has obvious advantages in description of fracture directivity and geometrical characteristics.

The invention discloses a background noise body wave extraction method and device based on distributed optical fiber acoustic sensing, and the method comprises the steps: obtaining an original phase difference signal along an optical fiber channel through a distributed optical fiber acoustic sensing system, and converting the original phase difference signal into strain rate data according to system demodulation parameters; performing preprocessing such as noise suppression and frequency energy balance on the strain rate data; calculating an autocorrelation function for the preprocessed signal, and superposing autocorrelation results of a plurality of time segments; performing band-pass filtering on the superposition autocorrelation function in a target frequency band, and extracting a body wave reflection response in background noise; and in order to eliminate the influence of the zero-time pulse in the shallow layer or weak reflection signal, carrying out mean value removal processing on the extraction result along the space direction to obtain a zero-offset body wave reflection response. The method can effectively describe the discontinuity from a superficial sedimentary layer and a fracture to a deep mourhua surface and even a lithosphere, and makes up for the defects of a conventional seismic station method.

The present application provides a method for extracting surface wave dispersion curves based on strain fields, including the steps of: extracting strain data from seismic observation data; preprocessing the strain data according to the type of the seismic observation data to obtain strain components; converting the strain components from the time-space domain to the frequency-space domain through Fourier transform; converting the strain components from the frequency-space domain to the frequency-phase velocity domain through frequency-Bessel transform to obtain the surface wave dispersion spectrum of the strain components; and picking up the surface wave dispersion curves according to the surface wave dispersion spectrum. The present application fills the technical gap in extracting surface wave dispersion information from DAS data, provides a powerful tool for extracting surface wave dispersion information applicable to single-component or multi-component DAS data, has important theoretical significance and practical value for the development of surface wave dispersion imaging methods based on DAS observations, and provides ideas for extracting the dispersion information of surface waves or body waves such as Rayleigh waves, Scholte waves, and Love waves.

The invention relates to the technical field of lithium ion battery nondestructive testing, and provides an ultrasonic phased array battery three-dimensional imaging method based on wave velocity correction. Firstly, phased array body wave full-matrix time domain data is utilized, and corresponding sound velocities of ultrasonic waves propagating in different directions in a battery are obtained. And then the corresponding sound velocity is used for a full-focusing method, phased array imaging of sound velocity correction is carried out, and a more accurate imaging result is obtained. And finally, the position of the phased array is moved through a mechanical arm and a stepping motor, and the collected ultrasonic B scanning image is reconstructed into a three-dimensional image. The result shows that the sound velocity correction is realized, so that compared with the traditional ultrasonic phased array imaging, the method can obtain a more accurate and specific battery defect imaging result, and the defect position is clearer under the same display threshold value. In addition, according to the method, wave velocity correction is applied to three-dimensional imaging of the battery, and a solution thought is provided for solving the problem that an economic, rapid and accurate imaging means is lacked in battery defect detection.

The invention provides a near-fault site multi-seismic-phase free field inversion method based on sphere / cylindrical diffusion characteristics, and a research system in the field of near-fault inversion is perfected. On the basis of spherical diffusion characteristics of body waves and cylindrical diffusion characteristics of surface waves, a near-fault site multi-seismic-phase free field inversion framework is constructed by adopting a dynamic stiffness matrix method, and an inversion problem is converted into a multi-target optimization problem for solving an epicentral distance and a seismic source depth; on the basis, the space-time difference of the free field displacement waveform is quantified by adopting a dynamic regular path distance, and a target function is constructed by taking the minimization of the three-dimensional displacement waveform difference of two similar points as a criterion; meanwhile, constraint conditions are set in combination with propagation attenuation characteristics of seismic waves, so that a near-fault inversion multi-objective optimization model is established; and then, a rapid non-dominated multi-objective genetic algorithm is introduced to solve a Pareto optimal solution of an optimization variable, and the optimal solution is substituted into an inversion framework to complete multi-seismic-phase free field inversion of the near-fault site.

The invention discloses a plateau frozen soil thickness detecting and monitoring method and system based on distributed optical fiber acoustic sensing. The method comprises the steps that a spiral optical fiber and a linear optical fiber are arranged in frozen soil according to a preset observation position, and vibration signals are collected through the spiral optical fiber and the linear optical fiber respectively; the collected vibration signals are preprocessed, and the vibration signals are converted into particle velocity signals; vector decomposition is carried out on two mass point velocity signals obtained by the spiral optical fiber and the linear optical fiber, and a surface wave component is inhibited to enhance a mass wave component; carrying out self-excitation and self-receiving recording on the measuring point position according to the data after vector decomposition; recording data and picking up frozen soil upper and lower limit travel time; according to the frozen soil upper and lower limit travel time, the overlying stratum speed and the frozen soil layer speed, obtaining the frozen soil upper limit burial depth and the frozen soil thickness. The device can output the spatial distribution condition of the frozen soil in real time, monitors the buried depth, thickness and upper and lower limit positions of the frozen soil in real time, improves the geological interpretation effect for railway investigation and design, and provides a scientific basis for safe operation of the railway.

The invention discloses a metal internal defect rapid imaging detection method based on frequency domain interpolation and laser ultrasound, and belongs to the field of laser ultrasound nondestructive testing. The method comprises the following steps: firstly, carrying out large-interval rapid scanning on a local area of the surface of a tested piece by utilizing laser ultrasound, obtaining a group of ultrasonic body wave time domain signals with the number of x at different positions of the surface of a material, and then carrying out two-dimensional Fourier transform on the obtained time domain signals to obtain a frequency-wave number two-dimensional signal matrix; zero filling is carried out on a high-frequency part in the frequency domain, and then two-dimensional inverse Fourier transform is carried out to obtain interpolation to obtain a group of n time domain signal matrixes (n is gt; and finally, carrying out synthetic aperture imaging processing on the interpolated time domain signal to obtain a high-resolution synthetic aperture imaging result. According to the invention, for metal internal defect detection and imaging, the problems of long time consumption, large required data volume and the like of traditional laser ultrasonic synthetic aperture detection can be effectively solved, and the laser ultrasonic synthetic aperture detection efficiency and the imaging resolution are greatly improved.

The invention discloses a surface acoustic wave device and a radio frequency front end module, the surface acoustic wave device comprises a piezoelectric layer, a sound velocity layer and an interdigital electrode, and the interdigital electrode comprises a plurality of electrode fingers. The piezoelectric layer is provided with a first surface and a second surface which are oppositely arranged, the interdigital electrode is arranged on the first surface of the piezoelectric layer, and the sound velocity layer is arranged on the second surface of the piezoelectric layer; sound waves generated when the surface acoustic wave device works comprise surface acoustic waves and body waves; the surface acoustic wave device has a first characteristic depth, and the thickness of the piezoelectric layer is smaller than the first characteristic depth; wherein the first characteristic depth is related to the midline distance between two adjacent electrode fingers of the interdigital electrode, the bulk wave sound velocity of the piezoelectric crystal in the x direction and the working frequency. The sound velocity layer is directly arranged below the piezoelectric layer, the thickness of the piezoelectric layer is limited to be smaller than the first characteristic depth, and the thickness of the piezoelectric layer is reasonably reduced, so that the sound velocity of the surface wave is obviously improved or reduced, and meanwhile, the influence on the effects of other functional layers is avoided.

The present invention relates to the technical field of non-destructive testing of lithium-ion batteries, and provides a method for three-dimensional imaging of batteries using an ultrasonic phased array based on wave velocity correction. First, the corresponding sound velocities of ultrasonic waves propagating in different directions in the battery are obtained using the full matrix time domain data of the phased array body wave. The corresponding sound velocities are then used in the full focusing method to perform phased array imaging with sound velocity correction, thereby obtaining more accurate imaging results. Finally, the position of the phased array is moved by a robotic arm and a stepper motor, and the collected ultrasonic B-scan image is reconstructed into a three-dimensional image. The results show that this method can obtain more accurate and specific battery defect imaging results compared to traditional ultrasonic phased array imaging due to the realization of sound velocity correction, and the defect location is clearer under the same display threshold. In addition, this method applies wave velocity correction to three-dimensional imaging of batteries, providing a solution to the lack of economical, fast and accurate imaging methods in battery defect detection.

The invention provides a defect type evaluation system and method based on electromagnetic ultrasonic echoes, and the system comprises an excitation signal transmitting module, an echo signal receiving module, a short-time Fourier transform module, and a defect type analysis module. Wherein the excitation signal sending module is used for sending a body wave excitation signal to a to-be-tested product so as to generate an ultrasonic vibration signal in the to-be-tested product; under the action of a to-be-detected defect in the to-be-detected product, the ultrasonic vibration signal forms an ultrasonic echo signal; the echo signal receiving module is used for receiving the ultrasonic echo signal and generating an echo voltage signal; the short-time Fourier transform module is used for performing short-time Fourier transform on the echo voltage signal to form an echo local frequency spectrum; and the defect type analysis module is used for analyzing the echo local frequency spectrum so as to judge the defect type of the defect to be detected. The problem that the defect type in the metal plate cannot be effectively identified can be solved.

The invention discloses a seaplane wave sliding load spectrum compilation method. The method comprises the steps of determining gravity center acceleration data of pool test data of each task section according to overall and structural parameters of a seaplane; comparing a gravity center acceleration time history curve representing the gravity center acceleration data with an airframe trim angle time history curve, and intercepting stable section data of each task section; performing power spectrum density analysis on acceleration overload / overload increment in the stable section data to obtain an acceleration characteristic frequency band; determining a cut-off frequency according to the acceleration characteristic frequency band, and filtering the stable section data; carrying out accumulated transcendental statistics on the filtered stable section data to obtain an accumulated transcendental curve of each task section; according to the time proportion of each task segment and the similarity criterion, obtaining an accumulative surpassing curve of each task segment of the real machine water surface operation; and forming a body wave sliding equivalent spectrum according to a damage equivalence criterion. The technical problem of compiling and verifying the water skiing fatigue load spectrum of the seaplane is solved.

The invention belongs to the technical field of geophysical exploration, particularly relates to a background noise seismic frequency imaging method and system based on autocorrelation, and aims to solve the problem that an existing background noise exploration method is insufficient in resolution. The method comprises the following steps: acquiring background noise data of a plurality of acquisition points in a target area and segmenting the background noise data to obtain horizontal component signals in different directions; performing self-correlation calculation on each horizontal component signal to obtain a plurality of sections of self-correlation sequences, performing frequency domain conversion, and performing superposition according to directions to obtain a north component characteristic frequency spectrum and an east component characteristic frequency spectrum; and combining the east characteristic frequency spectrum and the north characteristic frequency spectrum, mapping the combined frequency spectrum into the depth of the underground anomalous body, and generating a frequency imaging result. According to the method, after self-correlation processing, the passive source body wave signals are transmitted in a frequency domain and reflected on the ground surface through an underground geological interface to interfere and perform imaging, the exploration cost is low, the applicability is high, and the imaging resolution of low-speed anomalous bodies such as karst is high.

The invention discloses a bionic robotic fish cooperatively driven by rigid-flexible coupling pectoral fins and a variable-rigidity body, a left pectoral fin mechanism and a right pectoral fin mechanism are arranged in a mirror image manner and are mounted at an inclined included angle relative to a longitudinal neutral plane of a fish body, and branch fin bones in pectoral fins realize two-degree-of-freedom wing rocking and flapping movement by adopting coaxial gears and rope winding mechanisms; the pectoral fin on each side is provided with a plurality of fin rays, rigid and flexible joints are alternately matched with an elastic substrate and paired memory alloy wires for antagonistic actuation to realize controllable bending and traveling waves, and a hydrogel fin film is integrally poured outside the pectoral fin to form a continuous stress surface and ensure watertightness; the body part is driven by left and right pull wires which are wound and unwound in a differential mode and driving and driven gears to achieve bidirectional large-stroke bending, memory alloy actuators which are symmetrical up and down and hyperelastic wires are overlaid to regulate and control pretension and stress paths, and continuous adjustment of equivalent bending rigidity and damping is achieved. According to the structure, fin-body fusion, pectoral fin beat / wave coupling motion and body traveling wave propagation cooperative work are achieved under the compact size, and efficient propelling and sensitive maneuvering are both considered.

The utility model discloses a surface acoustic wave filter with high performance, which comprises a substrate layer, a piezoelectric layer and a resonator metal layer, the piezoelectric layer is arranged above the substrate layer, the resonator metal layer is arranged above the piezoelectric layer, and the resonator metal layer is arranged above the piezoelectric layer. The upper surface of an electrode connecting area in the resonator metal layer is further covered with a covering metal layer, a channel cavity is further formed in the portion, below the resonator metal layer, of the substrate layer, and the range of the channel cavity covers the interdigital transducer of the resonator metal layer. The surface acoustic wave filter can obstruct the transmission of body waves and improve the tolerance power at the same time.

A sound absorption device and method for an acousto-optic device that converts body waves into surface waves. The sound absorption device of the acousto-optic device mainly adopts a crystal similar to the acousto-optic crystal of the acousto-optic device, and the sound absorption crystal guides out and absorbs the sound energy in the acousto-optic crystal. The specific implementation method comprises the following steps: (1) calculating the sound velocity slowness curve of the acousto-optic interaction surface of the acousto-optic crystal and the sound absorption crystal; (2) using the Snell law of anisotropic crystals, calculating the phase velocity of the incident sound wave and the angle of the sound absorption surface when the reflected sound energy propagates along the interface at the sound absorption surface of the sound absorption crystal; (3) using the Snell law of anisotropic crystals, designing the angle of the connection surface between the sound absorption crystal and the acousto-optic crystal, so that the direction of the sound wave phase velocity in the sound absorption crystal is the design direction; (4) connecting the sound absorption crystal cut according to the design angle to the acousto-optic crystal, so that the ultrasonic energy is transmitted into the sound absorption crystal, and is converted from body waves to surface waves on the sound absorption surface and rapidly attenuated and absorbed, thereby improving the influence of the reflected sound field interference of the traditional sound absorption structure.

The invention discloses a nondestructive testing method for inner surface defects of a bearing raw material seamless steel tube. The nondestructive testing method comprises the following steps: S1, determining parameter indexes of a surface wave transducer; s2, designing a transducer array; s3, signal excitation and receiving are carried out through a transducer array; s4, quantifying the defect degree; and S5, defect imaging. The method solves the problem that eddy current detection and ultrasonic body wave detection hardware in the prior art are difficult to effectively detect pit defects on the inner surface of the seamless steel tube in principle, so that a detection method for high-precision detection of the bearing raw material seamless steel tube is lacked in the prior art.

The invention discloses a wall vibration isolation system suitable for periodic bending of a high and steep roadbed fill slope, which comprises a plurality of vibration isolation structure units arranged according to a period, each vibration isolation structure unit comprises a straight wall (1), an upper covering plate (2), a middle covering plate (3) and a bottom plate (4), and effective control of Rayleigh waves is realized through a specific structure size and arrangement mode; the straight wall (1) is a main body part of the vibration isolation structure unit, is arranged perpendicular to the ground and is used for reflecting a horizontal component of Rayleigh waves; the upper covering plate (2) is of a plate-shaped structure horizontally extending from the top of the straight wall (1) to the vibration source direction and is used for enhancing constraint of a top soil body and a wall body. The middle covering plate (3) is arranged at the middle position of the straight wall (1), horizontally extends towards the direction of a vibration source, is in synergistic effect with the upper covering plate (2), and is used for segmenting the influence range of Rayleigh waves; the bottom plate (4) is arranged at the bottom of the straight wall (1), horizontally extends towards the two sides and is used for restraining displacement of the bottom of the straight wall and promoting conversion from surface waves to body waves.

A borehole sonic logging tool and method for imaging. The borehole sonic logging tool may comprise a transmitter configured to transmit a sonic waveform into a formation, wherein the transmitter is a dipole, and a receiver configured to record a reflected wave as waveform data, wherein the receiver is a quadrupole. A method may comprise disposing a downhole tool into a borehole, selecting a frequency range for the transmitter to a horizontally-polarized shear formation body wave, broadcasting the sonic waveform as the horizontally-polarized shear formation body wave into the formation penetrated by the borehole with the transmitter, recording a reflected wave on the receiver as waveform data, wherein the reflected wave is the horizontally-polarized shear formation body wave reflected from a reflector, and processing the waveform data with an information handling system.

The present invention discloses a method and system for detecting and monitoring the thickness of permafrost on the plateau based on distributed fiber optic acoustic sensing. The method includes deploying spiral and linear optical fibers in the permafrost according to predetermined observation locations, collecting vibration signals using the spiral and linear fibers, respectively; preprocessing the collected vibration signals to convert them into particle velocity signals; vector decomposing the two particle velocity signals obtained from the spiral and linear fibers to suppress the surface wave component and enhance the body wave component; self-excited and self-received recording of the measurement point locations based on the vector decomposition data; extracting the upper and lower limit travel times of the permafrost from the recorded data; and obtaining the upper and lower limit burial depth and thickness of the permafrost based on the upper and lower limit travel times of the permafrost and the velocity of the overlying strata and the permafrost layer. The present application can output the spatial distribution of permafrost in real time, monitor the buried depth, thickness, and upper and lower limit positions of the permafrost in real time, and provide a scientific basis for improving geological interpretation for railway survey and design and ensuring safe railway operation.

The invention relates to the technical field of seismic exploration, in particular to a surface wave and body wave comprehensive exploration method and exploration system based on a seismic source, and the method comprises the steps: collecting seismic waves which are denoised by a detector in an exploration region; obtaining an instantaneous spectrogram of the seismic wave at each moment, and obtaining an energy value curve of each frequency; obtaining waveform characteristics and propagation speed when the energy value curve of any frequency has a sudden change point, and obtaining a waveform characteristic set of the detector; matching the waveform feature set of each detector according to the propagation speed, and calculating the attenuation rate of the waveform features; and comparing the attenuation rate with the attenuation threshold to obtain a surface wave component and a body wave component of each detector, and performing inversion to obtain an exploration result. According to the technical scheme, the surface wave signal and the body wave signal can be accurately separated, and then an accurate exploration result is obtained.

The application relates to the technical field of semiconductor devices, in particular to a bonding substrate, an elastic wave device and a module. The bonding substrate comprises a support substrate with a first surface and a second surface opposite to the first surface; a near-surface layer of the support substrate close to the first surface is an absorbing layer; the absorbing layer is a porous structure, and the pore diameter of the porous structure is below 1 nm. The bonding substrate provided by the application can make the longitudinal leakage energy of the elastic wave be transmitted and consumed in the absorbing layer, so that the stray signal cannot be reflected back to the device surface, thereby effectively absorbing the longitudinal leakage energy of the elastic wave device, reducing the body wave reflection and solving the stray signal of the elastic wave device.

The application discloses a background noise body wave extraction method and device based on a distributed optical fiber acoustic sensing, and the method comprises the following steps: acquiring an original phase difference signal along an optical fiber channel by using a distributed optical fiber acoustic sensing system, and converting the original phase difference signal into strain rate data according to system demodulation parameters; performing noise suppression, frequency energy equalization and other pretreatments on the strain rate data; calculating an autocorrelation function of the pretreated signal, and superimposing autocorrelation results of multiple time segments; performing band-pass filtering on the superimposed autocorrelation function in a target frequency band, and extracting a body wave reflection response in the background noise; in order to eliminate the influence of a zero-time pulse in a shallow layer or a weak reflection signal, performing a mean removal processing on the extraction result along a space direction, and obtaining a zero-offset body wave reflection response. The method can effectively depict discontinuities from a shallow sediment layer, a fracture to a deep Moho surface and even a lithosphere, and makes up for the shortcomings of a conventional seismic station method.

The application belongs to the technical field of geophysical exploration, and particularly relates to a background noise seismic frequency imaging method and system based on autocorrelation, aiming to solve the problem of insufficient resolution of the existing background noise exploration method. The method comprises the following steps: obtaining background noise data of multiple acquisition points in a target area and segmenting, to obtain horizontal component signals in different directions; performing autocorrelation calculation on each horizontal component signal, respectively, to obtain multiple autocorrelation sequences, then performing frequency domain conversion, respectively, and stacking according to the direction, to obtain a north component characteristic frequency spectrum and an east component characteristic frequency spectrum; merging the east component characteristic frequency spectrum and the north component characteristic frequency spectrum, to map the underground abnormal body depth, to generate a frequency imaging result. After autocorrelation processing, the passive source body wave signal propagation is used in the frequency domain to reflect on the ground interference for imaging through the underground geological interface, the exploration cost is low, the applicability is strong, and the imaging resolution of karst and other low-velocity abnormal bodies is high.

This invention discloses a multi-information source mechanism calculation method based on earthquake early warning station network observations. The method includes selecting velocity and acceleration recorded waveforms to form an input database; obtaining the P-wave initial motion polarity through manual picking and template matching techniques; calculating the source mechanism using a grid scanning method, and using solutions with an inconsistency ratio below a threshold as preliminary solutions; manually screening P-wave and S-wave phase waveforms; and jointly using initial motion polarity, S / P amplitude ratio, and body wave waveform as constraints to calculate the probability value of each preliminary solution. The probability distribution of clustered solutions is obtained through the Akaike information criterion and cluster analysis to obtain the optimal source mechanism calculation result. This invention, based on joint inversion calculations using acceleration records from early warning stations and velocity records from seismic stations, lowers the lower limit of the magnitude of earthquakes with computable source mechanisms. The comprehensive use of three types of information constraints improves the reliability of the results, and the calculation of the probability distribution of clustered solutions reduces the adverse effects of multiple solutions, thus improving the stability of the results.

A two-body wave energy converter utilizing a linear, universal modular absorber. A linear module, contains a direct drive linear machine for converting linear mechanical motion into electrical energy. The linear module is connected between two oscillating mechanical bodies, exploiting their relative motion. A wave activated floating body follows the wave motion, while a reaction body is tethered to a mass on the seabed providing a stable kinematic reference in operational waves. In large waves, the mass on the seabed lifts, providing heave compliance to the whole wave energy converter reducing ultimate loads in survival wave conditions.

The invention discloses an earthquake background noise super ghost reflection imaging method, and relates to the technical field of seismological detection. The method comprises the following steps: acquiring body wave background noise data acquired by a plurality of seismic stations on a ground surface survey line, selecting two adjacent stations as a first station and a second station, and taking the rest as auxiliary stations; and performing mutual correlation on the auxiliary station data and the first station data and the second station data to obtain a first mutual correlation result and a second mutual correlation result, and performing mutual correlation on the first mutual correlation result and the second mutual correlation result to obtain a bulk wave imaging result of the current auxiliary station on the adjacent station. And calculating and superposing the result of each auxiliary station to obtain the imaging result of the current adjacent station. And traversing all adjacent stations, and finally obtaining a background noise ultra-ghost reflection imaging result below the whole measuring line. The method provided by the invention can effectively improve the resolution of seismic background noise body wave imaging.

The invention discloses a joint inversion three-dimensional quality factor method, which comprises the following steps of: acquiring average attenuation travel time through an initial three-dimensional quality factor (Q value) and an average attenuation travel time formula, and acquiring a theoretical frequency spectrum amplitude at the frequency by combining a plurality of initial values including corner frequency, field effect, low-frequency amplitude and frequency and an amplitude formula; converting the displacement frequency spectrum amplitude in the frequency domain into an observation frequency spectrum amplitude in a natural logarithm domain, and obtaining a residual vector formula in combination with a theoretical frequency spectrum amplitude; a formula obtained after meshing of the seismic wave three-dimensional propagation speed and the initial Q value in the average attenuation travel time formula is substituted into a residual vector formula, smooth constraint and damping parameters are added to obtain a new residual vector formula, and the new residual vector formula is solved to obtain a value of a parameter disturbance quantity; superposing the values to the plurality of initial values to obtain a plurality of new initial values of the next round of iteration; and substituting the initial three-dimensional Q value back to a residual vector formula to obtain a residual vector, and taking the new initial three-dimensional Q value as a target three-dimensional Q value when a difference value between the residual vector and the amplitude meets a condition.

The invention discloses an underwater flexible robot three-dimensional motion control method, device and equipment, a medium and a product, and relates to the field of flexible robot automation technology and nonlinear dynamics modeling analysis control. The method is suitable for a robot with periodic fluctuation and flexible motion characteristics. The method comprises the following steps: acquiring information data of a target underwater flexible robot; according to the information data, on the basis of a body wave equation of the target underwater flexible robot, a physical experiment and fluid mechanics simulation method is adopted, fitting of hydrodynamic parameters is conducted, and a hydrodynamic equation is obtained; based on the Lagrange theory, a kinetic model is determined according to the hydrodynamic equation; performing closed-loop motion control based on a three-dimensional space according to the kinetic model to realize three-dimensional trajectory tracking control of the target underwater flexible robot; the three-dimensional space is determined based on the speed, course and depth of the target underwater flexible robot. The invention aims to realize three-dimensional motion control of the underwater flexible robot.

This invention discloses an electromagnetic ultrasonic online monitoring probe, device, and method for steam pipelines with a coating layer. The probe includes: a butterfly coil for supplying a DC-like current, or simultaneously supplying a DC-like excitation current and a strong pulse excitation current; and a zigzag coil for supplying a strong pulse excitation current. The zigzag coils are unequally spaced, with the spacing gradually decreasing from the input end to the output end. Supplying a DC-like excitation current into the butterfly coil generates a bias magnetic field; supplying a strong pulse excitation current into the butterfly coil excites ultrasonic body waves, while supplying a strong pulse excitation current into the zigzag coil excites ultrasonic guided waves, thereby enabling pipeline wall thickness and defect detection. The guided waves excited by the unequally spaced zigzag coils exhibit Chirp signal characteristics, allowing for pulse compression to improve the signal-to-noise ratio and resolution of the ultrasonic echo signal. The probe is small in size, unaffected by Curie temperature, and suitable for continuous high-temperature detection and detection in narrow areas.

The present invention discloses a non-destructive determination method, system, device and medium for the Young's modulus of a bulk alloy, relating to the technical field of alloy detection. The method includes: performing Brillouin light scattering on the target bulk alloy to obtain an alloy spectrum; the alloy spectrum includes Rayleigh surface waves and body waves; the body waves include shear waves and longitudinal waves; performing Lorentz fitting on the alloy spectrum to obtain the Rayleigh surface wave frequency shift and the body wave frequency shift; calculating the Rayleigh surface wave sound velocity and the body wave sound velocity according to the corresponding relationship between the sound velocity and the dispersion relationship, the law of conservation of momentum, the Rayleigh surface wave frequency shift and the body wave frequency shift; determining an independent elastic coefficient matrix according to the Rayleigh surface wave sound velocity and the body wave sound velocity; and calculating the Young's modulus of the target bulk alloy according to the independent elastic coefficient matrix and the Young's modulus formula. The present invention can improve the accuracy of Young's modulus detection without damaging the sample.