76 results about "Wave frequency" patented technology

The invention relates to the technical field of ocean renewable energy power generation, and particularly discloses a floating type wind wave combined power generation system model prediction control method, which comprises the following steps: establishing a nonlinear mathematical model of a floating type wind wave combined power generation system; determining a steady-state working condition point of the system; carrying out linear processing on the nonlinear model; constructing a discrete time prediction model; designing a target function; defining a state and an input constraint condition; performing real-time rolling optimization solution; and dynamically feeding back a correction mechanism. Starting from a wind wave excitation mechanism, on one hand, response in a turbulent wind frequency band is reduced through fan variable pitch control, and on the other hand, response in a wave frequency band is reduced through wave energy power generation device PTO control, so that tower footing load is effectively reduced, and pitching motion of a platform is restrained. Global multi-objective optimization is realized by designing an objective function, defining constraint conditions and solving the objective function.

The invention discloses a compensation operation simulation method for a telescopic active wave compensation trestle, and the method comprises the steps: taking sea condition parameters as input, combining a wave frequency response factor of a ship, and simulating the six-degree-of-freedom wave frequency motion of the ship; establishing a series coordinate system connected with a compensation mechanism on the telescopic active wave compensation trestle, and constructing a forward motion equation and a reverse solution equation of compensation motion; according to the compensation target position of the tail end of the telescopic active wave compensation trestle, the six-degree-of-freedom motion amplitude of the ship is combined, and the motion stroke of a compensation mechanism is reversely solved; differentiating the motion stroke of the compensation mechanism, calculating the speed and acceleration of the compensation mechanism, and determining the statistical value of the motion time sequence of the compensation mechanism; and finally, judging whether the telescopic active wave compensation trestle can compensate the ship motion caused by the sea condition or not according to the statistical value. Whether the compensation mechanism design of the trestle can compensate the ship motion under the sea condition or not can be judged according to the simulation result.

The invention relates to the field of roadway surrounding rock loosening circle test and analysis, in particular to a roadway surrounding rock loosening circle test and analysis method, which comprises the following steps: data acquisition: distinguishing the current roadway area, and acquiring parameter information of roadway surrounding rock through devices; the deep loose zone analysis is to analyze each displacement parameter of the deep roadway surrounding rock corresponding to each monitoring time point; according to the obtained reflected wave amplitude parameter values and the reflected wave frequency parameter values, the position information of the surrounding rock loose circle is analyzed; according to the remote safety monitoring, the state information of the surrounding rock loosening circle is monitored in real time, and when a threshold value is exceeded, an audible and visual alarm is given out, the loosening circle range obtained by each method is preliminarily determined, and then the loosening circle range is determined by comprehensively comparing the test results of each method in the same area; and the range and characteristics of the loose circle can be judged more comprehensively and accurately.

Some aspects of the described technology may include a method, including inducing a wave field in a biological sample, the wave field comprising waves having a wave frequency, scanning the sample at a scanning velocity to perform a plurality of spatial measurements of the sample, determining spatial data from the plurality of spatial measurements, amplitude demodulating the spatial data based on the wave frequency and the scanning velocity, and generating displacement data for the biological sample based on the amplitude demodulated spatial data.

The invention provides a real-time feedback control method for an arrayed wave energy conversion device, which comprises the following steps of: carrying out numerical modeling and hydrodynamic analysis on the arrayed wave energy conversion device, establishing a time domain motion equation and a space state equation of the arrayed wave energy conversion device, replacing a convolution term of the time domain motion equation with the state-space equation to obtain a motion state of the arrayed wave energy conversion device, and carrying out real-time feedback control on the arrayed wave energy conversion device. According to the method, wave spectrum characteristics and hydrodynamic response characteristics of floaters are combined, hydrodynamic interference among the floaters in an array system is comprehensively considered, a causal mapping relation between floater speed and wave exciting force is constructed, expected floater response speed is calculated, control force is applied to the PTO through a feedback control means, and the wave excitation force is calculated. The device is kept in an approximately optimal resonance state under the action of random waves, so that the speed of each floater is close to the optimal function extraction condition of each wave frequency, and efficient real-time extraction of wave energy is realized.

The invention provides a plasma transient time boundary-based terahertz wave spectrum regulation and control method and device, and the method comprises the steps: obtaining femtosecond laser and terahertz waves, and enabling the femtosecond laser and the terahertz waves to enter a terahertz wave transmission space through beam combination; when the femtosecond laser and the terahertz wave synchronously pass through a first position point, the terahertz wave after frequency spectrum regulation and control is obtained; the first position point is located in the terahertz wave transmission space, a time boundary caused by medium transient refractive index sudden change is formed at the first position point when the femtosecond laser ionizes gas to obtain plasma, and frequency shift occurs when terahertz waves pass through the time boundary. According to the invention, the modulation effect on the terahertz wave frequency demand can be realized according to the abrupt change of the refractive index caused by the transient generation of the plasma.

The present invention discloses a non-destructive testing stress evaluation method based on the static component of non-linear ultrasonic Lamb waves, belonging to the technical field of stress detection, including: S1. Construct a Rayleigh-Lamb equation introducing the non-linear theory of elastic bodies, and then determine the Lamb wave dispersion curve of the plate to be detected, and determine the excitation frequency and excitation mode of the excitation source according to the Lamb wave dispersion curve; S2. Excite the Lamb wave with the determined excitation frequency and excitation mode at one end of the stress detection area of the plate to be detected, and receive and extract the corresponding signal through the other end of the stress detection area; S3. Reverse the phase of the extracted signal, and re-excite and receive the signal with the reversed phase; S4. Process the received signal and calculate the ultrasonic non-linear coefficient as an evaluation parameter for the stress state of the plate to be detected. The fundamental wave frequency and mode of the present invention are more flexible in selection, can measure the relevant parameters of high-attenuation materials, and can effectively evaluate the early damage and stress state inside the materials.

The invention discloses a simulation test device for reservoir water level fluctuation erosion. The device comprises a water tank, a water inlet and outlet system, a wave making module, a sample tank and a data acquisition system, the water tank is of a cuboid structure, a water outlet is formed in the bottom, and water level scales are marked on the side wall. The water inlet and outlet system comprises a water inlet pipe which is connected with an external water tank and provided with an electromagnetic valve and a flow meter. A water outlet pipe is arranged on the other side of the bottom of the water tank and connected with a water outlet, and the water drainage rate is adjusted through a variable-frequency water pump; the wave making module comprises a wave making machine, the wave making machine is installed at one end of the water tank, a programmable servo motor is adopted to drive a push plate, and the wave frequency of 0.5-5 Hz and the wave height of 5-30 cm are supported to be adjusted. Dynamic water level coupling waves are achieved, real-time linkage control over water level rising and falling and wave parameters is achieved for the first time, and the problem that a traditional device is single in working condition is solved; and modular design and high-precision data acquisition are also realized.

A transducer structure for a surface acoustic device comprises a composite substrate comprising a piezoelectric layer, a pair of inter-digitated comb electrodes, comprising a plurality of electrode means with a pitch p satisfying the Bragg condition, wherein the inter-digitated comb electrodes are embedded in the piezoelectric layer such that, in use, the excitation of a wave propagating mode in the volume of the electrode means is taking place and is the predominant propagating mode of the structure. The present disclosure relates also to an acoustic wave device comprising at least one transducer structure as described above and to a method for fabricating the transducer structure. The present disclosure relates also to the use of the frequency of the bulk wave propagating in the electrode means of the transducer structure in an acoustic wave device to generate contribution at high frequency, in particular, above 3 GHz.

The present disclosure provides a fracture parameter prediction method and related equipment, and relates to the technical field of fracture parameter prediction in oil and gas exploration and development. The method comprises: acquiring seismic data; performing variational mode decomposition on the seismic data to obtain connotation mode component (IMF) data of different scales; and based on the IMF data, using an alternating multiplier method to gradually perform fracture weakness inversion to obtain target fracture parameters. According to the embodiment of the present disclosure, the seismic data can be adaptively divided into different scales, and the noise in the effective wave frequency band range can also be suppressed to a certain extent. Finally, multi-scale fracture weakness inversion is realized in the time domain, and stable fracture prediction is realized.

The application discloses a rate integration hemispherical resonator gyro angular rate output method, and belongs to the technical field of inertial technology. The application is aimed at solving the problem of large measurement noise of standing wave azimuth angle and poor gyro output precision in the existing rate integration hemispherical resonator gyro control method. In the application, the inherent working frequency of the gyro is taken as the initial value of the forward traveling wave frequency and the reverse traveling wave frequency, and the reference signals of the forward traveling wave and the reverse traveling wave are calculated and obtained; the reference signals are used to demodulate the electrode detection signals by using a low-pass filter, and the secondary demodulation quantity of the gyro angular rate is obtained by using the primary demodulation quantity; the phase difference between the forward traveling wave and the reverse traveling wave of the two groups of electrode detection signals and the forward traveling wave and the reverse traveling wave reference signals is calculated; the forward traveling wave and the reverse traveling wave reference signals are used to calculate the closed-loop real-time tracking of the forward traveling wave and the reverse traveling wave of the hemispherical resonator, and the sensitive axis angular rate measurement value of the rate integration hemispherical resonator gyro is calculated. The application is used for the angular rate output control of the rate integration hemispherical resonator gyro.

The present invention discloses a method for actually measuring the attenuation coefficient of broadband laser ultrasonic Lamb waves in metal thin plates, belonging to the field of nondestructive testing. Data acquisition stage: Use a nanosecond laser to set a point source excitation on the surface of an aluminum alloy thin plate, and then use a scanning laser Doppler vibrometer (SLDV) to measure the wave field and collect linear wave field data. Data processing stage: Use the time-frequency analysis of continuous complex wavelet transform to obtain the time-frequency spectrum of the one-dimensional wave field signal. Determine the effective analysis range, including the time upper limit and the frequency upper limit. Extract the amplitude data represented by the intercept line. Attenuation characteristic analysis stage: Extract the peaks of the amplitude data at multiple distance points to obtain discrete points of the amplitude change with distance at a specific frequency. The present invention provides a method for actually measuring the attenuation characteristics of broadband laser ultrasonic Lamb waves. The solution of the attenuation coefficient provides an important theoretical reference for the calculation of the effective detection range and the selection of the filtering frequency of damage scattered waves.

This invention provides an adaptive high-efficiency wave energy generation device and method, including a linear generator, a data acquisition device, a motor, an energy-absorbing float, a connecting rod, and a central controller. At least one motor is mounted on the bottom of the linear generator, and the bottom of each motor is connected to the energy-absorbing float. The connecting rod is mounted on the top of the energy-absorbing float and extends into the linear generator. The data acquisition device and the motor are both signal-connected to the central controller. The central controller drives the motor to apply optimal output force to the energy-absorbing float based on the output data from the data acquisition device. The energy-absorbing float achieves extremely high wave energy capture efficiency for the current ocean waves. It actively adjusts the force output by the motor to the energy-absorbing float for different wave frequencies, ensuring that the force output by the motor is always equal to the optimal output force, thus achieving all-weather high-efficiency wave energy capture.

The present application relates to a method for obtaining secondary current, a device, a computer device, a storage medium, and a differential protection method. Stray current data is obtained, and the stray current data includes the amplitudes of each low-frequency component and the fundamental wave frequencies of each low-frequency component; the primary current of the current transformer is obtained according to the amplitude of the low-frequency component, the fundamental wave frequency, the preset amplitude of the primary-side power frequency current, and the power frequency; the bias magnetic quantity is obtained according to the amplitude of the primary current, and the transformation rule corresponding to the bias magnetic quantity is determined; the secondary current of the current transformer is obtained according to the primary current and the transformation rule. This solution obtains the bias magnetic quantity by obtaining the amplitude of the primary current of the current transformer, determines the transformation rule corresponding to the bias magnetic quantity, obtains the secondary current of the current transformer according to the primary current and the transformation rule, and further obtains the influence of stray current on differential protection, which can answer whether stray current will affect differential protection for actual power grid operation and propose warning values and corresponding improvement measures.

The application provides a method for identifying thin interbedded gas layers based on low-frequency acoustic signals, belongs to the technical field of unconventional natural gas exploration, and solves the problem that the prior art cannot apply low-frequency acoustic signals of earthquakes to identify oil and gas reservoirs; the method comprises the following steps: S1, calculating the pore elastic parameters of a target layer, and constructing a pore elastic stratum model of the target layer; S2, calculating the pore elastic wave field response characteristics of a single interface or a stratum group of the target layer, and establishing a reflection amplitude and wave frequency relationship volume; S3, performing frequency division processing on seismic records, and determining the position of low-frequency amplitude anomalies; S4, calculating vertical pore elastic wave seismic records, combining the pore elastic wave field response characteristics and the reflection amplitude and wave frequency relationship volume, and interpreting the position of low-frequency amplitude anomalies to determine a region related to thin interbedded gas layers; the application can effectively determine the position relationship between low-frequency amplitude anomalies and gas layers in seismic records, fills the gap in the exploration technology, and improves the interpretation accuracy of seismic identification of gas layers.

The invention discloses a dual-terminal distance measurement method and system based on traveling wave attenuation characteristics, and relates to the field of power system fault distance measurement. Voltages and currents of buses at the two ends of a line are measured, and phase-mode transformation and traveling wave decomposition are carried out; establishing a fault traveling wave frequency domain wave equation according to results of phase-mode transformation and traveling wave decomposition, and converting the fault traveling wave frequency domain wave equation into a time domain wave equation; and determining a measured fault traveling wave data window, and substituting traveling wave data in the fault traveling wave data window into the time domain wave equation for solving to obtain a fault distance. Dependence of a traditional method on data synchronization is overcome, and accuracy and practicability of power transmission line fault distance measurement are improved.

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 present application relates to a kind of wave frequency energy emission devices, the device includes: electromagnetic modulation layer, for modulating preset frequency and power electric signal pulse, and change magnetic field is generated according to the electric signal pulse;Energy conversion layer is arranged in the magnetic field range of the change magnetic field, and the energy conversion layer is used to convert the magnetic field energy of the change magnetic field into vibration energy wave;The energy conversion layer is composed of one or two kinds of strain materials, and the expansion rate and response time of each strain material are different;The vibration energy wave is used to cause the resonance inside target object, to change the state of the target object.The present application utilizes the characteristics that the energy conversion layer generates expansion with the change of electromagnetic field, causes vibration, thereby converts into high-frequency vibration wave, thereby improves the efficiency and effect of energy output.

The disclosure relates to a sensor for a quantity of a medium, such as the permittivity of the medium. This sensor comprises at least one sensitive element capable of: injecting waves, the injection being controlled by the application of an input signal, and collecting received waves, perturbed by physical properties of the medium related to said quantity, to form an output signal having, with respect to the input signal, a modulation from which a measurand indicative of said quantity of the medium is determined. The sensor also comprises a control unit capable of generating said input signal with a wave frequency to be injected corresponding to a chosen excitation frequency, and a processing unit applying a demodulation of the output signal to determine the corresponding measurand. In particular, the processing unit is configured to cooperate with the control unit to generate the input signal.The excitation frequency is adjusted according to the input and output signals using a feedback loop within the processing unit. This maintains a linear response of the output signal over a range of measurands by continuously adjusting the excitation frequency. The feedback loop is thus configured to ensure constant sensor sensitivity over this range. (See Figure 4 for an abstract diagram.)

Disclosed is buoyant wave energy capture device, adapted to float adjacent to an upper surface of a body of water over which waves pass, and adapted to capture a portion of the radiated waves created by its own rising and falling in response to incident and / or passing environmental waves. A power take off mechanism combined with the disclosed wave energy capture device may be tuned to a specific wave frequency, and thereby optimally extract energy from a motion of a single frequency, even the wave energy capture device may be excited and / or energized by waves of any of a relatively broad range of frequencies, thereby increasing the power-generation and cost efficiencies of such devices relative to wave energy conversion devices of the prior art.

The invention discloses a self-adaptive elastic tube double-oscillation water column wave energy conversion device, which belongs to the technical field of ocean energy utilization and comprises an elastic tube, hard tubes at two ends and an in-tube oscillation water column, and an adjusting assembly in the hard tubes is electrically connected with a free end turbine device and a controller. The adjusting assembly comprises internal and external liquid level sensors, a bidirectional water pump and adjusting blades capable of surrounding air adjusting holes. The device combines a double-oscillation water column with the elastic pipe, improves the natural oscillation period, is easy to resonate with waves, converts wave energy at two ends, absorbs energy along the full length of the elastic pipe, and improves the energy capturing efficiency and the space range; the system oscillation period can be adjusted by adjusting the pore diameter of the air hole, and the efficient frequency bandwidth is widened; different wave frequencies are matched, and the power generation efficiency of the device is improved. The flexible structure of the elastic tube improves the survivability under extreme wave conditions; the two-way water pump can adjust internal water pressure according to wave water level and wave height to adapt to tide level change and enhance protection, the water surface of an oscillating water column in the pipe is stable, and the overall stability is high.

The invention discloses a working capability analysis method for a multi-dimensional active wave compensation crane. The working capability analysis method comprises the following steps: S1, establishing a space rectangular coordinate system; s2, simulating six-degree-of-freedom wave frequency motion of the ship under the given sea condition, constructing a forward motion equation and a reverse solution equation of the position of the hoisted weight, and calculating a compensation instruction time sequence of each compensation mechanism on the ship under the given sea condition; s3, calculating a statistical value of the compensation instruction time sequence, establishing a judgment criterion, and judging whether the multi-dimensional active wave compensation crane can work or not; s4, determining a work capability rose diagram and a work capability look-up table diagram; and S5, calculating the annual workable probability of the multi-dimensional active wave compensation crane. According to the method, the annual workable probability of the multi-dimensional active wave compensation crane is rapidly calculated.

The present invention discloses a method and system for predicting a stress intensity factor transfer function, relating to the field of artificial intelligence technology. The method includes: after processing data on stress intensity factors, crack information, and wave frequencies, training a multi-layer perceptron model to obtain a multi-layer perceptron model capable of predicting stress intensity factors under different regular waves; constructing a stress intensity factor transfer function based on the predicted stress intensity factors to calculate the crack growth driving force, and calculating the corresponding crack growth amount based on the crack growth driving force; statistically obtaining the crack growth life curve under random sea conditions by counting the short-term sea condition experience time; statistically analyzing the fatigue life of an ocean structure based on the stress intensity factor transfer function under different crack sizes, and comparing the statistical results with the finite element results to obtain the corresponding fatigue life of the ocean structure, which helps to solve the problem that the prior art cannot efficiently and accurately statistically analyze the fatigue life of ocean structures.

The application provides a wave equation full-wave Q tomography method, which comprises the following steps: performing FFT transformation on existing seismic records to determine the frequency of a Ricker wavelet; performing forward simulation using the frequency of the Ricker wavelet determined in step 1 to obtain seismic correlation data; converting the seismic correlation data to a local domain and performing FFT on the data in the local domain to obtain the frequency of a single seismic event; obtaining the peak frequency shift of each seismic event in the local domain according to the frequency of the single seismic event; obtaining a companion source according to the peak frequency shift; performing wave field continuation calculation according to the companion source to obtain a back-propagating wave field; obtaining a gradient using the back-propagating wave field; and performing iterative updating using a conjugate gradient method according to the gradient to finally obtain an updated Q model. The method provided by the application can be simulated to obtain a relatively accurate Q model.

The present application relates to the field of wave energy generating buoy, disclose a kind of after bending pipe wave energy generating buoy and its air turbine switching device and method.For the defects that the existing single turbine buoy can only adapt to specific wave frequency, wide operating condition, low power generation efficiency, and easy to overload damage in extreme sea conditions, the present application connects wiles turbine and impact turbine at the end of single after bending pipe air path, real-time monitoring of wave frequency by wave frequency sensor, sliding guide cover driven by motor driving screw rod, to realize the adaptive switching of two turbines.When the wave frequency exceeds the effective range, the impact turbine is selected by default;In the effective range, greater than the threshold frequency selects the impact turbine, and less than the threshold frequency selects the wiles turbine.The present application combines the performance advantages of two turbines, the annual average power generation efficiency is improved by 32%, the turbine service life is extended to 8 years, the power supply reliability is more than 95%, and is suitable for power supply in offshore scenes such as islands and offshore platforms.

The invention discloses an arbitrary-shape fixed structure wave load identification method based on field wave elevation, relates to the field of ocean engineering structure health monitoring, and aims to solve the problem that a traditional method depends on incident wave information and is only suitable for a simple structure. The method comprises the following steps: averaging M surface elements on a wet surface of a discrete structure; pre-calculating and storing a transfer matrix which only depends on the structure geometry, the measuring point position and the wave frequency; wave elevation time history data of W measuring points are collected in real time, and main frequency components are reserved through fast Fourier transform; calling a corresponding transfer matrix, and obtaining a surface element pressure Fourier component through matrix multiplication; and performing inverse transformation to synthesize a pressure time history and integrating to obtain a total wave load. The invention also discloses a system for realizing the method, electronic equipment, a computer program product and a storage medium. The method is high in universality, does not need incident wave information, is efficient in calculation, and is suitable for various fixed ocean structures.

The invention relates to a cable insulation fault positioning method and system, and the method comprises the following steps: collecting a three-phase voltage traveling wave signal when a cable has a single-phase insulation damage grounding fault, and carrying out the signal decoupling, and obtaining an independent line mode component and a zero mode component; a Db45 wavelet basis is used as a mother wavelet, multi-scale wavelet decomposition and reconstruction are carried out on the decoupled line mode component so as to extract fault traveling wave head features, and the number of layers of multi-scale wavelet decomposition is determined according to the sampling frequency and the power grid fundamental wave frequency; and according to a wavelet reconstruction result, detecting the moment when a fault traveling wave head arrives at monitoring points at two ends of the line, thereby calculating the distance from a fault point to one end of the line. Compared with the prior art, the method has the advantages that inter-phase coupling interference is eliminated through phase-mode transformation, and serious voltage distortion and harmonic interference in a power grid are effectively suppressed by using the excellent time-frequency localization characteristic of the Db45 wavelet basis, so that the accuracy and reliability of cable insulation fault positioning are greatly improved.

The application discloses a rock elastic wave frequency dispersion and attenuation characteristic measurement system and method, and relates to the technical field of rock mechanics, and can be used for measuring the rock elastic wave frequency dispersion and attenuation characteristic of a rock sample. The measurement system comprises an axial pressure control chamber, the lower part of the axial pressure control chamber is provided with a confining pressure bin, the pressure application end of the axial pressure control chamber is located at the upper part of the confining pressure bin, the inside of the confining pressure bin is further provided with a probe body, the probe body is used for bonding with a rock sample, the inside of the confining pressure bin is further provided with a positioning and sealing device used for placing the rock sample, heating fins are further installed on the inner wall of the confining pressure bin, the positioning and sealing device is further connected with an exciter through an excitation pipeline, and a force sensor is installed on the excitation pipeline. By pre-embedding an ultrasonic signal generating device in the probe body, the problem that a sample cannot be repeatedly tested in an ultrasonic frequency band during a medium and low frequency band test is solved, a closed loop control servo hydraulic loading mode is adopted for the axial pressure controller and the confining pressure controller to replace a traditional gas pressure application mode, the target pressure can be quickly and accurately reached, and the safety of the experimental process can be ensured under high confining pressure.

The invention relates to a wave signal acquisition device, preferably a seismic acquisition device, comprising a housing (1); a wave sensor system housed inside the housing (1) and coupled to the bottom wall of the housing. The housing (1) is provided with an acoustic black hole (2) made of polymer, preferably flexible, so as to absorb parasitic wave frequencies below 500 Hz, preferably below 400 Hz. Figure for the abstract: Fig. 5