91 results about "Wave frequency" patented technology

The invention relates to the field of ocean conductivity data processing, and discloses an Argo conductivity data correction method based on the influence of thermohaline internal waves, which comprises the following steps: installing a thermohaline depth sensor and an acoustic Doppler flow velocity profiler on an Argo buoy, sampling seawater in the vertical direction, and calculating the depth of the sampled seawater; acquiring temperature, salinity and flow velocity profile data of seawater; determining the upper and lower boundary depths of the thermohalocline and the thickness of the thermohalocline according to the acquired data, calculating the internal wave frequency and the internal wave number, and calculating the temperature internal wave amplitude, the salinity internal wave amplitude, the temperature internal wave phase and the salinity internal wave phase; establishing a conductivity data correction model according to the calculated parameters; and performing dynamic correction on the conductivity data by using the model. According to the method disclosed by the invention, the accuracy and the reliability of conductivity data can be remarkably improved, and support can be provided for research in many fields such as research on physical characteristics of the ocean thermocline and halocline, ocean ecological environment and ocean material circulation.

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 provides a bistable stochastic resonance-based wave power generation device. The bistable stochastic resonance-based wave power generation device comprises a cylindrical linear generator, a rack and a bistable movement mechanism, the device can be directly installed on various suitable offshore carriers, when the offshore carriers shake under the action of waves, the cylindrical linear generator converts mechanical energy into electric energy, the mover is triggered to do bistable motion through the bistable motion mechanism, and the capture bandwidth and efficiency of the device on random wave frequency are improved. The cylindrical linear generator, the bistable motion mechanism with the spring as a main tool and the rack are combined, wave energy power generation based on the bistable principle of potential energy trap crossing motion is achieved, the capture bandwidth of the device for random wave frequency is widened, the energy capture efficiency when the wave frequency is low is improved, and the device is suitable for large-scale popularization and application. The conversion efficiency of the power generation device to random wave energy is improved, and the adaptability of the device to external continuously-changing sea conditions is improved.

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 discloses a non-destructive testing stress evaluation method based on a nonlinear ultrasonic Lamb wave static component, and belongs to the technical field of stress detection, and the method comprises the following steps: S1, constructing a Rayleigh-Lamb equation introducing an elastomer nonlinear theory, and further determining a Lamb wave frequency dispersion curve of a to-be-detected plate, the excitation frequency and the excitation mode of the excitation source are determined according to the Lamb wave frequency dispersion curve; s2, exciting lamb waves for determining excitation frequency and excitation mode at one end of the stress detection area of the plate to be detected, and receiving and extracting corresponding signals through the other end of the stress detection area; s3, inverting the phase of the extracted signal, and exciting and receiving the inverted signal again; and S4, processing the received signal, and calculating an ultrasonic nonlinear coefficient as an evaluation parameter of the stress state of the plate to be detected. According to the invention, the selection of the fundamental wave frequency and mode is more flexible, the related parameters of the high-attenuation material can be measured, and the early damage and stress state in the material can be effectively evaluated.

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 shipborne water cannon platform adjustment method and device based on jet deviation prediction and ship attitude prediction, and relates to the technical field of water cannon platform adjustments, the method comprises the following steps: obtaining a real-time video frame image, a real-time brightness value, a real-time wave height, a real-time wave frequency, real-time air humidity and real-time visibility; establishing an image segmentation model in which the brightness value, the wave height, the wave frequency, the air humidity and the visibility are introduced, and inputting the real-time data into the image segmentation model to segment a water column image, a striking drop point image and a target image to be struck; and determining a real object distance deviation and iteratively adjusting a yaw angle and a pitch angle of the water cannon platform until the target is completely hit. According to the method, during image segmentation, the image segmentation model in which the brightness value, the wave height, the wave frequency, the air humidity and the visibility are introduced is used for segmenting the image, the influence of external environment factors is fully considered, the segmented image is more accurate, and it is guaranteed that a follow-up water cannon platform is accurately adjusted to hit a target.

The invention provides a processing method and device for ocean P guided wave removal and mode separation. The method comprises the following steps: determining a frequency dispersion energy spectrum corresponding to a marine seismic gather in a frequency-speed domain based on an original seismic record corresponding to the marine seismic gather in a time-space domain; and removing frequency dispersion energy except the specified P guided wave frequency dispersion mode in the frequency dispersion energy spectrum to obtain a target frequency dispersion energy spectrum. And inverting the target frequency dispersion energy spectrum to a time-space domain to obtain a target seismic record corresponding to the specified P guided wave frequency dispersion mode. And based on the original seismic record and the target seismic record, determining seismic data after the P guided wave frequency dispersion mode is removed. Wherein the extracted P guided wave seismic data is used for inversion of a frequency dispersion curve and a waveform so as to realize high-precision detection of a seabed longitudinal wave velocity structure or marine geological survey; the seismic data after the P guided wave frequency dispersion mode is removed is used for analyzing the influence of the P guided wave on the seismic signal and the amplitude spectrum of the seismic signal, and de-noised seismic data is provided for migration imaging of the reflected wave.

The invention belongs to the technical field of oil exploration, and relates to a pump noise suppression method and system for a while-drilling continuous wave mud pulse signal, and the method comprises the steps: collecting an original mud pulse signal containing a continuous wave pulse signal; pump noise fundamental waves are determined according to the recognized fundamental wave frequency of the pump noise in the original mud pulse signals; constructing a linear time-invariant state space model of the k-order harmonics according to an unsteady state pump noise model constructed by utilizing the pump noise fundamental waves, and constructing a linear time-invariant measurement model of the k-order harmonics; performing pump noise prediction on the constructed linear time-invariant state space model by using adaptive Kalman filtering to obtain an optimal pump noise posteriori estimated value at each moment; reconstructing a pump noise signal in the continuous wave mud pulse observation signal calculated by the linear time-invariant measurement model through the pump noise posterior estimation value to obtain a reconstructed pump noise signal containing all order harmonics; and subtracting the reconstructed noise signal from the original mud pulse signal to obtain a continuous wave mud pulse signal after the pump noise is suppressed. According to the invention, unstable pump noise signals can be efficiently and reliably inhibited.

The invention discloses a working method and system of a biological frequency complex wave frequency intervention device and a storage medium, and the working method of the biological frequency complex wave frequency intervention device comprises the steps: receiving an instruction of a user related to a complex wave frequency needing to be formed; according to the instruction, a composite wave frequency is formed through a biological frequency composite wave frequency intervention device, the composite wave frequency comprises a main frequency, a secondary main frequency lower than the main frequency and a super main frequency higher than the main frequency, and the secondary main frequency, the main frequency and the super main frequency are in multiple relation; and radiating the composite wave frequency towards a preset direction through the biological frequency composite wave frequency intervention device.

The invention provides a floating type wind energy and wave energy combined power generation device, and belongs to the technical field of new energy application. The direct-driven generator is directly driven through vertical movement of the buoy shell, so that direct conversion of mechanical energy is realized, and intermediate energy loss is reduced; the combination of the buoy shell and the elastic cable has high response sensitivity and is suitable for different wave frequencies and amplitudes; the wave response is optimized by adjusting the buoyancy center of the cavity of the buoy; and the elastic mooring rope can absorb dynamic impact of waves and transmit energy at the same time, so that the device adapts to various wave frequencies and amplitudes, and the resonance phenomenon is avoided. The device comprises a semi-submersible type floating platform and a floating type wind driven generator, and further comprises an oscillating floater type wave energy power generation assembly. A floating type wind driven generator is fixedly arranged in the middle of the semi-submersible type floating platform, and three sets of oscillation floater type wave energy power generation assemblies are arranged on the periphery of the bottom of the floating type wind driven generator at equal angles.

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 belongs to the technical field of wave energy power generation, and discloses a novel oscillating water column wave energy conversion device that can adapt to wave conditions. The front wall of the device can move forward and backward and rotate, and the front and rear positions of the front wall can be adjusted according to the incident wave conditions, so that the natural frequency of the oscillating water column in the device matches the incident wave, thereby ensuring that the device can have a good wave energy capture efficiency under waves of different frequencies; a hydraulic energy catcher is connected to the top of the front wall, and one end of the hydraulic energy catcher slides on a guide rail to absorb the kinetic energy generated by the rotation of the front wall, further improving the energy capture effect of the wave energy device. Based on the characteristic of being able to change the width of the air chamber of the oscillating water column wave energy device, the present invention improves the wave frequency adaptability of the device, so that it can achieve efficient conversion of wave energy under conditions of incident waves of different frequencies, and the swingable front wall can further improve the energy capture effect of the device.

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 invention relates to the field of marine engineering technology, and in particular to an energy dissipation floating breakwater structure with a resonance cavity moored with serial buoys, comprising a floating breakwater body, which comprises a movable airtight chamber, a floating breakwater wave-facing side and a floating breakwater back-wave side, the airtight chamber is arranged between the floating breakwater wave-facing side and the floating breakwater back-wave side, and the bottom unclosed gap between the airtight chamber and the floating breakwater wave-facing side constitutes a first resonance chamber, and the bottom unclosed gap between the airtight chamber and the floating breakwater back-wave side constitutes a second resonance chamber; and a mobile control device is stored in the airtight chamber, and the mobile control device controls the airtight chamber to move toward the floating breakwater wave-facing side or the floating breakwater back-wave side based on a detected wave period, so as to adjust the widths of the first resonance chamber and the second resonance chamber, so that the natural frequency of the energy dissipation floating breakwater structure is the same as the detected wave frequency, thereby achieving a better wave dissipation effect.

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.)