918 results about "Sine wave" patented technology

According to the power cable multi-defect nondestructive testing method and system based on the broadband impedance spectrum, impedance characteristics of a cable under different frequencies are measured, frequency domain data are converted into time domain data through inverse Fourier transform, and accurate positioning and evaluation of internal defects of the cable are achieved; the invention discloses a power cable multi-defect nondestructive testing method based on a broadband impedance spectrum. The method comprises the following steps: step 1, signal output and acquisition; the method comprises the steps that a broadband impedance spectrum tester is used for outputting a broadband sine wave voltage signal, frequency domain measurement data are collected, and the frequency domain measurement data are impedance data of a cable under different frequencies; 2, carrying out time-frequency conversion; converting the frequency domain measurement data into time domain data through inverse Fourier transform, generating a time-amplitude curve, and analyzing the electrical characteristics of the cable; 3, establishing a defect identification model; analyzing the electrical characteristics of the cable at different frequencies by using the transmission line model, and evaluating the state of the cable; step 4, defect positioning and evaluation; and 5, displaying and analyzing a result.

The invention discloses a tower grounding grid multi-frequency composite wave electric field imaging and soil environment medium diagnosis method, which comprises the following steps of: generating a composite excitation signal through superposition of a low-frequency sine wave and a high-frequency CHIRP square wave, and collecting multi-dimensional data such as voltage / current response, soil temperature and humidity, electric field intensity and the like in combination with a distributed sensor array; separating signal features by using wavelet transform and extracting impedance information of a target frequency point; a multi-grid homotopy algorithm is adopted to realize grounding grid three-dimensional resistivity distribution reconstruction, corrosion spots and abnormal areas are marked, and high-precision positioning of underground conductors is completed through UWB radar or a capacitance detector; meanwhile, based on the information entropy maximization optimization frequency band combination, the grounding grid state is comprehensively evaluated in combination with a multi-parameter fusion model. The method has the non-contact patrol capability, the unmanned aerial vehicle carries equipment to scan the grounding grid, the detection efficiency and convenience are remarkably improved, and an efficient and accurate solution is provided for guaranteeing safe operation of the power grid.

The invention belongs to the technical field of flow field optical measurement, and particularly relates to a high-enthalpy plasma gas temperature measurement method, system and device based on an absorption spectrum. Generating a composite modulation signal through a high-frequency sine wave and a low-frequency sawtooth wave, and enabling incident light to pass through a flow field measurement area in parallel through laser modulation and beam shaping; the detector receives the transmission light and converts the transmission light into an electric signal containing harmonic information, the signal acquisition device is used for performing signal acquisition, the phase-locked demodulation algorithm is used for extracting second harmonic, and the temperature is inversely deduced by combining the double-spectral-line temperature measurement method and the Fourier coefficient amplitude ratio of the second harmonic with the HITRAN database. The system comprises a signal driving module, a laser emission module, a detection acquisition module and a temperature measurement module. The device is composed of a signal generator, an in-phase adder and the like, and a laser is matched with a driving power supply to guarantee stable work. According to the scheme, aiming at the problems of weak signal absorption and insufficient signal-to-noise ratio under complex working conditions, the measurement accuracy and reliability are improved by composite modulation, harmonic extraction and a bispectral line algorithm, and an effective means is provided for research on thermal characteristics of the high-enthalpy plasma.

The invention provides a current transformer dielectric loss anti-interference measurement method based on a variable frequency power supply, and relates to the technical field of power detection, and the method comprises the steps: constructing an excitation channel, collecting a background response signal, recognizing a main interference frequency through combining a frequency tracking algorithm, and dynamically constructing a frequency deviation parameter; generating a pair of non-power-frequency excitation frequency control variable-frequency power supplies to output sine wave excitation signals; excitation voltage and response current signals are synchronously collected to form sampling signals, notch frequency is set according to frequency deviation parameters, main interference is filtered out, and first processing signals are obtained; performing weighting processing by constructing a window function matched with the frequency band characteristic to generate a second processing signal; the complex amplitude and phase information at the target frequency is extracted, the complex impedance is calculated based on the complex current method, the dielectric loss value of the current transformer is finally output, and the anti-interference capability and precision of measurement are effectively improved. According to the invention, the interference in the dielectric loss measurement of the current transformer can be processed, so that the measurement precision is improved.

The invention belongs to the technical field of sewage treatment and membrane separation, and provides an in-situ nondestructive membrane pollution detection system and method based on an ultrasonic transmission signal, and the system comprises an ultrasonic excitation module which is used for generating a sine wave excitation signal which penetrates through a membrane body to excite the ultrasonic transmission signal for pollution detection; the signal processing module is used for continuously collecting and preprocessing ultrasonic transmission signals of the clean membrane body and the membrane bodies with different pollution degrees, extracting ultrasonic transmission signal characteristics under different pollution degrees, and establishing a pollution thickness-signal characteristic mapping model; wherein the ultrasonic transmission signal features comprise a time-frequency domain energy gravity center feature and a frequency attenuation spectrum slope feature; and the pollution detection module is used for judging the pollution stage of the membrane body to be detected based on the pollution thickness-signal feature mapping model, and completing in-situ nondestructive membrane pollution detection. According to the technical scheme, the sludge pollution state in the ceramic membrane and flat membrane filtering process can be monitored in real time, and early warning and pollution dynamic tracking are achieved.

The invention discloses an eddy current displacement sensor sine constant current source excitation method, and belongs to the technical field of sensor measurement and control. The method comprises the following steps: S1, generating positive and negative symmetric reference voltages through a reference voltage source circuit; s2, outputting a square wave control signal with adjustable frequency by the control chip, and driving a switching circuit to generate a square wave taking the positive and negative reference voltage as a level; s3, processing the square wave through a filter circuit to obtain a standard sine wave voltage signal; and S4, converting the sine voltage signal into sine constant current source excitation through a Howland current source circuit, and outputting the sine constant current source excitation to a sensor probe coil. According to the invention, through combination of digital control and analog conversion, the circuit structure is simplified, the cost is significantly reduced, and convenient adjustment of the output frequency and high stability and precision of the output current are realized at the same time.

The invention belongs to the field of gear machining detection, and particularly relates to a cylindrical gear ghost order detection method and detection equipment based on tooth surface waviness analysis. The method comprises the following steps: firstly, acquiring tooth surface deviation data of each tooth in a gear, carrying out resampling, inclination error correction and de-modification on the tooth surface deviation data, and then combining the tooth surface deviation data into full-tooth deviation curves in four directions; and then extracting waviness data and generating a full-tooth waviness curve. After RC is carried out on a full-tooth waviness curve, on one hand, the full-tooth waviness curve is converted into a frequency domain signal for selecting a frequency range, on the other hand, spectral analysis is carried out on a waviness signal through an iterative sine wave fitting algorithm within the specified frequency range, sine wave components are extracted, and a corresponding order spectrum is generated. And finally, when a sine wave component of which the amplitude is greater than or equal to 0.02 mu m and which is in a non-integral multiple harmonic order with the tooth number exists in the order spectrum of the target gear, detecting the gear ghost order. According to the invention, the problem of lack of a high-precision and high-efficiency waviness analysis and gear ghost order detection method in the prior art is solved.

The invention discloses a super-flat wire common-winding motor and a design method, and belongs to the technical field of motor design and manufacturing. The invention discloses an equal-pole common-winding axial magnetic flux motor and a design method, the equal-pole common-winding axial magnetic flux motor comprises a motor winding, a stator, a rotor, a casing and the like, and is characterized in that the number of magnetic poles of the stator and the number of magnetic poles of the rotor are equal, all the magnetic poles of the stator or the rotor on the same disc are excited through the same annular coil winding, and the winding can be a conventional round wire, a flat wire or a super-flat wire; alternatively, two or more concentric circle winding units, such as an outer ring winding unit and an inner ring winding unit, can be arranged on the same disc, radially adjacent iron cores can be shared or can also be independently arranged, meanwhile, the radial size of the shared iron core can be wider in consideration of the magnetic saturation problem, or the radial size of the shared iron core can be smaller in consideration of the magnetic saturation problem. The radial sizes of the iron core and the winding in the small-diameter area can be larger; the working principle can be a reluctance type, a switch reluctance type, a permanent magnet synchronous type, a direct-current motor type or an alternating-current motor type; the direct current motor can be a commutator or a plane commutator; or a brushless control scheme; the alternating current motor can be square wave, sine wave or other waveform; the phase difference of the three-phase alternating current can be 120 degrees; or two-phase or four-phase alternating current or other phase difference current with the phase difference of 90 degrees.

The invention discloses a polycrystalline silicon solar panel intelligent fault detection early warning system and method, and relates to the technical field of intelligent fault detection. The polycrystalline silicon solar panel intelligent fault detection early warning system comprises a power attenuation fault detection module; a hot spot effect fault detection module; and a short circuit fault detection module. According to the invention, power attenuation early warning timeliness analysis is carried out, whether sine wave signal extraction optimization determination and early warning are carried out is determined, then hot spot effect early warning timeliness analysis is carried out, whether hot spot effect optimization determination and early warning are carried out is determined, and finally short circuit early warning timeliness analysis is carried out. According to the method, whether temperature-waveform extraction optimization judgment and early warning are carried out or not is judged, accurate and timely early warning of faults such as power attenuation, hot spot effect and short circuit is achieved, and the problem that in the prior art, fault detection and early warning of the polycrystalline silicon solar panel are not timely due to interference in the fault feature extraction process is effectively solved.

The invention relates to the technical field of meteorological observation, in particular to a parameter measurement method and device based on a dual-band mode, equipment and a storage medium. Generating a dual-band excitation signal according to the aligned sine wave signal; analyzing the echo signal according to a preset gain coefficient, a time difference method and a preset attitude compensation formula to obtain a reconstructed quasi-unipolar pulse, an actual wind speed, a horizontal wind direction angle, a pitch angle, a three-dimensional wind speed vector, a roll angle and a real wind direction; acquiring real-time air pressure, and correcting a preset standard state sound velocity according to a preset sound velocity correction formula and the real-time air pressure to obtain a corrected sound velocity; according to the scheme, a dual-band signal attached to a medium is generated, after efficient transmission analysis, high-resolution pulses and multi-dimensional wind field parameters are obtained by means of gain, a time difference method, attitude compensation and the like, the sound velocity is corrected in combination with air pressure, comprehensive, accurate and rapid updating of data are considered, and the measurement reliability is improved.

A method for obtaining a motion surrogate signal in medical imaging, the method comprising the steps of: receiving 102 a projection stack comprising a plurality of two-dimensional projections of a patient volume; selecting a plurality 104 of sub-volumes of the projection stack; extracting 106 a candidate motion surrogate signal from projection data contained within each sub-volume of the projection stack to create a plurality of candidate motion surrogate signals; and combining 108 the plurality of candidate motion surrogate signals into a single final motion surrogate signal. The final surrogate may be an average of the candidate set or their weighted sum, the weights possibly being noise-dependent. The method may be implemented iteratively. A reference signal, possibly a sinusoid may be compared to the candidate surrogates. Differences between sub-stacks may be computed. High or low-frequency variations may be removed from the signals.

The invention relates to a current control method for a continuous casting blank stirrer, and the method comprises the steps: setting control parameters of a variable-frequency controller in an electromagnetic stirrer, enabling an actual current to rise to a target current value, controlling the current to be increased to a current oscillation upper limit value at a certain rate, and then enabling the current to be reduced to a current oscillation lower limit value at a certain rate, and the circulation is repeated, so that the continuous casting electromagnetic stirring current is changed in a periodic sinusoidal waveform. The electromagnetic stirring current is controlled to change in a periodic sinusoidal waveform, so that the carbon segregation of the casting blank is improved, the carbon segregation range of the casting blank is reduced, the internal components of the casting blank are more uniform, and the performance of the casting blank is improved.

The invention provides an argon arc welding tungsten electrode appearance defect detection method and system and a storage medium, and relates to the technical field of tungsten electrode appearance detection.The method comprises the steps that firstly, a sample electrode with known defects is subjected to three-dimensional scanning and discretization into a plurality of space points, and each point is endowed with a defect existence mark; by applying a composite sine wave excitation current, an eddy current signal generated when a collector spirally passes through a detection coil at a constant speed is acquired, and laser ultrasonic scanning is synchronously utilized to acquire full-matrix data and reconstruct a three-dimensional gray model. And constructing a double-branch deep learning model, fusing the eddy current feature vector and the ultrasonic image block feature, and learning a mapping relationship between the eddy current feature vector and the defect mark. And performing the same detection on a to-be-detected electrode, outputting the defect confidence of each position by using the trained model, calculating a comprehensive quality index in combination with a preset defect severity weight and a spatial key region weight, and judging whether the electrode is qualified or not according to a qualified threshold value. According to the invention, high-precision, automatic and comprehensive detection of surface and internal defects is realized.

The invention discloses a cable high-frequency impedance characteristic analysis method based on bipolar trapezoidal wave excitation, and belongs to the technical field of power equipment state monitoring and fault diagnosis. In order to solve the problems of low test efficiency, insufficient high-frequency parameter modeling precision and weak anti-interference capability in cable high-frequency impedance characteristic analysis of a traditional sine wave excitation method, the method comprises the following steps: generating an odd-symmetry bipolar trapezoidal wave excitation signal with specific frequency and amplitude, and injecting the signal into the head end of a cable to be tested through a coupling device after power amplification; synchronously acquiring a high-frequency response signal of the key position of the cable under the excitation of the bipolar trapezoidal wave by using a data acquisition system; preprocessing the high-frequency response signal, converting the high-frequency response signal into a frequency domain through Fourier transform, calculating input impedance of the cable under different harmonic frequencies, and synthesizing a broadband impedance spectrum; based on the broadband impedance spectrum, the amplitude-frequency characteristic and the phase-frequency characteristic of impedance are analyzed, and cable state evaluation, partial discharge detection, insulation defect diagnosis or fault point positioning are realized. The method is used for an electric power system.

The invention relates to the technical field of power grid measurement, in particular to a miniaturized wireless self-powered alternating current electric field measurement method and system. Comprising the following steps: acquiring radio frequency energy in an electric field environment, and converting the radio frequency energy into direct current electric energy through a radio frequency energy acquisition system consisting of a microstrip antenna, a voltage doubling rectifying circuit and an energy management circuit; an alternating current electric field signal is collected through a differential dual-electrode sensor structure, and an electric field voltage signal is generated; amplifying the voltage signal through an instrument amplifier, and obtaining a digital signal of the electric field signal through an analog-to-digital conversion circuit; and processing and analyzing the alternating current electric field information according to the digital signal. By combining a radio frequency energy acquisition technology with a differential dual-electrode sensing structure, the electric field sensor has the performance characteristics of self energy supply, miniaturization, high precision, wide frequency response and low power consumption. The system can measure various types of electric field signals, including sine wave, triangular wave and square wave electric field signals, has a wide frequency range and a wide measuring range, and is excellent in linearity.

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

A transmitter system comprises a mapper configured to map data bits and power information to multiple subcarriers, producing mapped information. A first-level modulator converts this mapped information into subcarrier specifications, each defined by a complex number indicating amplitude and phase. The system includes multiple data stream / power channel digital paths, each with a frequency selector that processes a portion of the subcarrier specifications. An orthogonal subcarrier generator translates these specifications from frequency to time domain, generating baseband real and imaginary signals. A second-level modulator processes these signals with intermediate-frequency sine and cosine waves to produce IF I and IF Q signals. A beamformer modifies the phase and / or amplitude of these signals across multiple antenna channels, creating directed signals. Finally, a combiner adds output signals from each data stream / power channel digital path, directing them to corresponding antenna channel modules, facilitating efficient transmission across multiple channels.

The invention discloses a root mean square value RMS detection method and system, and belongs to the technical field of measurement and control. Wherein a to-be-detected voltage signal is preprocessed by the filter amplification circuit, a square wave signal synchronous with a sine wave zero crossing point is generated through the zero crossing comparison circuit, a signal period boundary is identified, and an integral number of complete and continuous signal periods are extracted in real time through the period detection module; the cycle information identified by the cycle detection module is transmitted to the data storage and processing module, meanwhile, the sampling signal of the high-speed ADC module is transmitted to the data storage and processing module, and sine wave data sampled by the high-speed ADC module is subjected to point-by-point square operation; the square values in a complete period are accumulated and summed, and an original sampling sequence is not stored; fIR digital filtering is carried out on the RMS values of continuous C periods through a digital filtering module; and the dynamic response performance of the system under different frequency bands is remarkably enhanced while the measurement precision is improved.

A triple-active bridge (TAB) converter and methods to optimize the same is disclosed. The TAB converter includes a high-frequency three-winding transformer and three active full bridges, each coupled to the high-frequency transformer through a different passive network. The converter also includes a centralized controller providing gating pulses to semiconductor switches within the active full bridges, a power pulsating buffer (PPB) configured to reduce capacitor requirements on the DC port, and an unfolder stage to convert rectified AC voltage to a pure sine wave. The centralized controller may optimize performance by varying at least one of a switching frequency, a duty cycle of bridge voltages, and a phase shift between bridge voltages. The PPB may include a buck active power decoupler with a half-bridge, inductor, and capacitors, and also a primary full bridge and a power transfer impedance block.

The invention discloses a quantum phase-locked detection method based on entanglement enhancement, and the method comprises the steps: encoding quantum bits in a ground state and an excited state, and preparing the quantum bits into an initialized quantum state; loading a periodic multi-pulse sequence to act on the quantum bits; and loading a carrier pulse resonating with the ground state and the excited state, detecting the final quantum state of the quantum bit, and comparing curves of each component of the measurement density matrix and the theoretical density matrix changing along with the pulse time interval of the periodic multi-pulse sequence to obtain the half cycle and the amplitude of the sine wave to be measured. According to the method, measurement noise under the condition that the rotation angle and the detuning error exist can be effectively restrained, high measurement precision is kept under the condition that the rotation angle and the detuning error exist, and the robustness enables the method to be more reliable in practical application.

Disclosed in the present invention are a method for precise transmission and parsing of a phase-cut transmission control signal, a control system, an apparatus and a gateway device. On the basis of a live wire alternating current sinusoidal signal, generation of a zero-crossing pulse signal is triggered every T / 2 cycle; a synchronization signal immediately follows the generation triggering of a current zero-crossing pulse; during a valid identification cycle Ta, a falling edge of an alternating current half wave is caused to generate a right notch corresponding to a time tR, or an original state is maintained until a next zero-crossing pulse is generated; the generation of a zero-crossing pulse represents a first digital signal, and the generation of a right notch represents a second digital signal, signals outside the cycle Ta being invalid. A midpoint between a rising edge and a falling edge of each zero-crossing pulse is used as a theoretical zero-crossing point to trigger timing, and the position of the theoretical zero-crossing point is corrected in real time for each zero-crossing pulse signal, thereby eliminating communication errors caused by alternating current interference; a synchronization signal and a valid identification cycle are used to mark the start and the end, thereby achieving precise parsing; and when there is no data transmission, only zero-crossing pulses are generated, thereby reducing energy consumption.

The adder sets a voltage upper limit value (VU) by adding a first voltage to a sinusoidal reference voltage (VREF) having a frequency and a phase consistent with an AC voltage (VI). The first integrator time-integrates a first deviation (VI-VU) of an instantaneous value of the AC voltage (VI) from a voltage upper limit value (VU) if the instantaneous value of the AC voltage (VI) exceeds the voltage upper limit value (VU). The voltage rise detection circuit detects a voltage rise of the AC voltage (VI) when a first integral value of the first integrator exceeds a first threshold value. The subtractor sets the voltage lower limit value (VL) by subtracting the second voltage from the reference voltage (VREF). The second integrator time-integrates a second deviation (VI-VL) of the instantaneous value of the AC voltage (VI) from the voltage lower limit value (VL) when the instantaneous value of the AC voltage (VI) is below the voltage lower limit value (VL). The voltage drop detection circuit detects a voltage drop of the AC voltage (VI) when the second integral value of the second integrator exceeds a second threshold value.

A driving signal generator includes a window function code generator, a sine wave code generator, an operation circuit and a signal converter. The window function code generator generates a first code corresponding to a window of a first sine wave. The sine wave code generator generates a second code corresponding to a second sine wave, wherein a frequency of the second sine wave is higher than a frequency of the first sine wave. The operation circuit is coupled to the window function code generator and the sine wave code generator, and performs an operation on the first code and the second code to generate an output code. The signal converter is coupled to the operation circuit and generates a touch driving voltage of a driving signal by converting the output code.

The invention relates to a ground resistance detection method and device in a high-voltage test, computer equipment, a computer readable storage medium and a computer program product. The method comprises the following steps: injecting a pilot frequency sine wave signal of a non-power frequency harmonic wave into a grounding loop in a high-voltage test, and collecting a response signal in the grounding loop; performing multi-stage filtering processing on the acquired response signal to obtain an effective amplitude and a signal characteristic of the response signal; calculating a grounding resistance value of the grounding loop based on the effective amplitude and the signal characteristics of the response signal; the grounding resistance value is compared with a preset resistance threshold value, and whether a preset abnormal factor exists in the grounding loop or not is analyzed; and when the grounding resistance value exceeds a preset resistance threshold value and / or the grounding loop has a preset abnormal factor, triggering an alarm and controlling the high-voltage test equipment to be powered off. By adopting the method, the grounding resistance can be detected in a non-direct contact manner in a high-voltage test.

The invention discloses a carbon fiber prepreg laying layer defect detection method and system based on nonlinear guided waves, and the method comprises the steps: arranging excitation and receiving sensor arrays at the inner side and the outer side of a carbon fiber prepreg region, transmitting Hanning window modulation sine wave signals through the excitation sensor arrays, arranging an acoustic metamaterial layer on the surface of a detection region, and detecting the defects of the carbon fiber prepreg laying layer through the acoustic metamaterial layer. An excitation sensor array is divided into two groups to emit different phase signals, so that wave beams are focused at specified positions in a detection area and interact with each other, normalized time-frequency analysis is performed on reference signals and to-be-detected signals, second harmonic components and sideband frequency components are extracted, a relative nonlinear coefficient is calculated based on a signal difference value, and the relative nonlinear coefficient is calculated. And processing and receiving full matrix data of the sensor array by adopting a full focusing method, and reconstructing a nonlinear coefficient distribution image in the carbon fiber prepreg to carry out defect positioning and quantitative evaluation on the acoustic metamaterial layer. According to the invention, accurate and reliable detection and early warning of micro-defects in the carbon fiber prepreg laying process are realized.

The invention discloses a gear micro-texture current-assisted laser processing method and device. The method comprises the steps that a gear three-dimensional model is established, and a curved surface processing path is generated; a laser is controlled to emit laser, the gear space attitude is adjusted, a dynamic focus lens is controlled to adjust the focal length of a laser beam based on a curved surface machining path, an X-direction galvanometer and a Y-direction galvanometer are controlled to adjust the direction and angle of the laser beam, and a laser spot is focused on a to-be-machined area of the gear; meanwhile, high-frequency pulse current is applied to the to-be-machined area, and the current waveform is sine wave; and high-pressure airflow is jetted. The laser energy absorption rate of the gear surface is increased, the temperature field is homogenized, and the plasma shielding effect is weakened, so that the integrity and uniformity of the texture contour are improved, splashing and burrs are reduced, and the machining quality and efficiency are improved. And machining is suitable for the complex curved surface of the gear, high-precision and high-consistency micro-texture machining is achieved, and the requirements for lubrication, friction reduction and fatigue resistance of a high-end gear are met.

The application provides a kind of FMCW laser radar signal processing method and system, method includes: the laser signal generated by laser is divided into measurement light signal and local light signal;Input measurement light signal to light modulator, modulate by modulated sine wave sweep signal;Amplify modulated measurement light signal, emit to the detection target by circulator, collimating mirror, receive reflected signal;Coupling with reflected signal, enhance the energy of signal light, carry out photoelectric signal conversion;Amplify converted electrical signal, carry out electrical mixing in mixer, output intermediate frequency signal;Low-pass filter processing is carried out to intermediate frequency signal;In signal processing system, intermediate frequency signal is converted into pulse square wave by high-speed comparator, carries out capacitance analog interpolation processing, measures intermediate frequency signal period, calculates intermediate frequency signal frequency value.The application solves the technical problem that the counting error of ±1 word leads to the period of to-be-measured intermediate frequency signal, the distance calculation precision of detection target is low.

Various aspects of the present disclosure generally relate to wireless communication. Some aspects more specifically relate to using one or more clock synchronization signals comprising sine waves to calibrate a local clock at an ambient internet of things (IoT) device. In some aspects, the ambient IoT device may receive a mixed signal comprising a pair of dual-tone sine waves and calibrate the local clock using a difference in frequencies of the pair of dual-tone sine waves.

The invention provides a light-induced force microscope system and an application method thereof. The system comprises a first laser, an atomic force microscope probe, a photosensitive detector, a first lock-in amplifier, a control box, piezoelectric ceramic, a second lock-in amplifier, a semiconductor laser, a light path system, a sample table, a piezoelectric scanning tube and a host. According to the light-induced force microscope system, the semiconductor laser is used, sine wave modulation is directly carried out on the semiconductor laser through the oscillator in the lock-in amplifier, and the light-induced force microscope system can accurately measure light force information at a needle point-sample position by using a common silicon needle point probe in the atmosphere. By analyzing the light force information, the light-induced force component can be qualitatively identified, and the rigidity, polarizability and other property information of the material can be reflected. According to the invention, accurate measurement of the light force signal on the surface of the two-dimensional material is realized, and a technology which is economical, simple in structure and convenient to operate is provided for identifying components and defects of the two-dimensional material in electronic devices, optoelectronic elements and sensors.

The invention discloses a capacitor health degree detection method and equipment, and the method comprises the steps: applying a sine wave test signal to a to-be-detected capacitor, obtaining a current signal and a voltage signal of the to-be-detected capacitor, calculating the phase angle of the to-be-detected capacitor through the current signal and the voltage signal, calculating the equivalent series resistance and capacitive reactance of the to-be-detected capacitor based on the phase angle, and obtaining the health degree of the to-be-detected capacitor. And calculating the capacitance of the to-be-measured capacitor based on the capacitive reactance, calculating the loss tangent value of the to-be-measured capacitor according to the equivalent series resistance and the capacitive reactance, and predicting the health degree of the capacitor according to the equivalent series resistance, the capacitance value and the change of the loss tangent value. Therefore, when the capacitor operates normally, current and voltage signals of the capacitor can be measured actively, and the health degree of the capacitor can be calculated by combining the equivalent series resistance, the capacity and the loss tangent value of the capacitor, so that the health condition of the capacitor can be evaluated more accurately and comprehensively, and early warning and troubleshooting can be carried out on the abnormal capacitor as soon as possible.