279 results about "Frequency detection" patented technology

The invention discloses a membrane bioreactor membrane pollution prediction method and system, and relates to the technical field of pollution detection. The method comprises the following steps: setting a frequency detection strategy, and connecting a membrane bioreactor to obtain a membrane feedback signal based on the frequency detection strategy; performing feedback signal fluctuation time sequence characteristic analysis based on the membrane feedback signal to obtain a feedback signal characteristic; the feedback signal features are combined with reactor operation parameters to be imported into a mechanism hybrid prediction model, mechanism constraint is carried out through a mechanism constraint layer according to the feedback signal features, data analysis is carried out on time series data features on the basis of the mechanism constraint through a data driving prediction layer, and a membrane state prediction result is obtained; and performing membrane pollution state analysis and progress prediction according to the membrane state prediction result, and generating a membrane pollution prediction data chain. The technical problems that in the prior art, membrane pollution prediction depends on an empirical threshold, so that recognition lags and precision is insufficient are solved, and the technical effect of improving membrane pollution prediction accuracy and real-time performance is achieved.

The invention discloses an MEMS resonator low ripple error temperature measurement system based on voltage feedback compensation, and the system comprises a trans-impedance amplifier, an analog-to-digital converter, a frequency detection module, a PI controller, a variable gain amplifier, a Schmitt trigger, a first digital-to-analog converter, a biasing circuit, mode switches S1 and S2, and a voltage feedback compensation loop. The compensation loop comprises an amplitude detection module, a lookup table, a second digital-to-analog converter and an adder; the amplitude detection module receives the digital signal from the analog-to-digital converter and outputs a vibration amplitude signal in real time; the lookup table receives the vibration amplitude signal, inquires and outputs a corresponding digital compensation voltage, and converts the digital compensation voltage into an analog voltage through a second digital-to-analog converter; the adder adds the analog voltage and a fixed bias voltage to generate a dynamic bias voltage and applies the dynamic bias voltage to a drive electrode of the MEMS resonator. According to the system, an amplitude-driving end bias voltage feedback compensation loop is introduced, so that the periodic ripples of the resonant frequency are effectively suppressed.

The invention discloses a broadband low-power-consumption receiving and transmitting shared phase shifter which comprises a differential signal common port, a frequency sampling and control circuit, a dual-mode orthogonal generation circuit and a passive vector modulation synthesis circuit. The differential signal common port comprises a common input / output port interface of RF + and RF-differential radio frequency signals; the frequency sampling and control circuit is composed of a frequency sampling circuit, a frequency detection circuit and a logic control unit. The dual-mode orthogonal generation circuit is composed of a frequency selection change-over switch, a multi-phase filter, a coupling transformer, a matching network 1 and a matching network 2. The passive vector modulation synthesis circuit is composed of two passive vector modulation arrays and two combining / power dividing circuits.

The invention discloses an ultrasonic stress-induced ice layer breaking deicing method, system and device for an insulator, and the method comprises the steps: sequentially transmitting a first frequency detection signal and a second frequency detection signal through an ultrasonic transmitting unit, collecting a reflection signal, and judging whether ice coating exists or not based on the characteristic difference of amplitude attenuation, propagation time difference and phase offset; if icing exists, deicing ultrasonic waves with initial power are transmitted, a power adaptive adjustment model is constructed by using real-time signals reflected by an icing layer, and the deicing power is dynamically optimized in combination with the characteristic change rate; the double-frequency signals are transmitted again at regular intervals, and after re-check reflection signals are collected and subjected to temperature correction, whether ice coating is completely removed or not is judged through characteristic differences; the system comprises an ultrasonic transmitting / receiving module, an icing judgment module and a power adaptive adjustment module. The device comprises a high-frequency ultrasonic generator, an ultrasonic transducer and a microcontroller. The device realizes integration of ultrasonic detection, deicing and effect verification, and is suitable for various insulator winter icing removal scenes.

The present disclosure provides a radio frequency receiving unit and a method of signal reception thereof, in particular, a radio frequency receiving unit is provided. The radio frequency receiving unit comprises a plurality of signal processing paths, at least one receiving port, each of the at least one receiving port being configured to receive a received signal having any frequency within a full bandwidth encompassing a predetermined range of frequencies, a frequency detection unit configured to detect a frequency band to which the received signal belongs, and a control unit configured to control routing, based on the detected frequency band, of the received signal to a corresponding signal processing path for processing.

The invention relates to the technical field of industrial X-ray detection, in particular to an image-based automatic voltage and current adjustment algorithm, which dynamically adjusts voltage and current according to real-time feedback of an image, accurately controls exposure parameters of X-ray equipment, effectively avoids overexposure or underexposure of the image, and improves the detection accuracy. Images with uniform gray scale, clear details, high contrast and reliable quality can be obtained, and a foundation is built for subsequent analysis and diagnosis. On the other hand, the whole adjustment process is automatic, manual repeated test parameters are not needed, the equipment debugging time is greatly shortened, standard images can be rapidly obtained, the detection efficiency is greatly improved, and the method is particularly suitable for large-scale and high-frequency detection tasks. In addition, the voltage and the current are always compared with the maximum value of the equipment during adjustment, excessive parameter operation is prevented, equipment damage is effectively avoided, the service life of the equipment is prolonged, and the maintenance cost is reduced.

The embodiment of the invention provides a signal period measurement method, a microcontroller, a storage medium and a program product, and relates to the technical field of signal frequency detection, the method comprises the following steps: in response to a timer capture event or a timer overflow event, executing an interrupt service program of a central processing unit; executing the interrupt service program of the central processing unit, which comprises the following steps of: when the interrupt service program is determined to be called in response to the timer overflow event, performing cumulative counting on the occurrence frequency of the timer overflow event to obtain a cumulative overflow frequency; and under the condition of determining that the interrupt service program is called in response to the timer capture event, calculating an actual period value of the tested signal according to the current accumulated overflow times and the capture period value, and resetting the accumulated overflow times. According to the embodiment of the invention, the period is calculated through the cumulative counting of the timer overflow events and the counting of the timer capture events, and the problem that the timer is limited by digits and cannot give consideration to low-frequency band width period coverage and measurement precision is solved.

The invention relates to the technical field of ship stern shaft vibration detection, in particular to a ship stern shaft sealing vibration frequency detection device which comprises a sealing pipe, a detection assembly for achieving frequency detection through vibration conduction is arranged in an inner cavity of the sealing pipe, and the detection assembly comprises a mass block arranged in the inner cavity of the sealing pipe. A partition plate is vertically mounted in the center of the top of the mass block, metal reeds are arrayed on the top of the mass block relative to the partition plate, a connecting spring is fixedly mounted in the center of the bottom of the mass block, a bottom plate is fixedly mounted at the bottom of the connecting spring, and the bottom plate is fixedly connected with the bottom of an inner cavity of the sealing pipe; through the array metal reeds arranged at the top of the mass block, the characteristics that the heights of the array metal reeds are different and the inherent frequencies of the array metal reeds are different are utilized, and when the ship stern shaft vibrates, the metal reed closest to the current main vibration frequency resonates.

The utility model relates to the technical field of laser application, in particular to a laser frequency stabilization device based on an etalon frequency measurement technology, which comprises a laser emission unit, a frequency detection unit, a frequency stabilization laser output end and a master control adjusting unit, the frequency detection unit comprises an optical splitter, an optical attenuator, a first photoelectric detector, an etalon and a second photoelectric detector. An etalon in the frequency detection unit is used as a frequency reference, an optical attenuator is arranged to reduce temperature rise and improve precision, a first photoelectric detector and a second photoelectric detector are used to provide a frequency measurement error signal and a reference signal, and the master control adjustment unit is used to carry out analysis and calculation according to the error measurement signal and the reference signal. And the laser emitting unit adjusts the laser frequency according to the adjusting signal, so that the frequency stabilization adjustment of the laser is realized.

Frequency Detection Pixel This description concerns a pixel (PIX2) comprising a first node (202), a second node (200) configured to receive a first DC potential (Vdd2), and a plurality of acquisition channels (CH1, CH2), each comprising: a photodiode (PD1, PD2) adapted to detect radiation (SIGL) in a first wavelength range; a capacitive element (Cc1, Cc2) coupling the photodiode to the first node (202); and a resistive element (R1, R2) coupling a first terminal (K1, K2) of the photodiode (PD1, PD2) to the second node (200). Figure for the abstract: Fig. 2

The invention relates to the technical field of motor resonant frequency detection, in particular to a motor resonant frequency detection method and device, a chip and electronic equipment. Using the offset data to calibrate the anti-induced electromotive force signal of the motor to obtain a first anti-induced electromotive force signal, and obtaining the resonant frequency of the motor according to the detection result of the first anti-induced electromotive force signal; through the mode, the influence of the imbalance data of the anti-induced electromotive force signal on the detection of the resonant frequency is eliminated, and the detection accuracy of the motor resonant frequency is improved.

The invention relates to the technical field of sound wave positioning, and provides a sound wave positioning multi-label identification and wake-up system and method.The system comprises a transmitting end and a receiving end, and the transmitting end modulates unique identification information of a label to a sound wave carrier through a coding modulation circuit according to a preset frame structure; a coding sound wave signal containing a lead code, a mode code and ID data content is formed, an RFID signal is synchronously transmitted, after a decoding circuit of a receiving end receives the signal, two-stage wake-up detection is carried out by utilizing an integrated frequency detection and mode correlator, interruption is generated only when the mode code is matched to wake up a main control unit, the main control unit reads the decoded ID, and the RFID signal is sent to the receiving end. And matching verification is carried out on the tag and the ID in the RFID signal, and the distance of the tag which is successfully matched is calculated according to the time difference of arrival of the two signals. According to the invention, through the coding sound wave, double-wave pairing and intelligent wakeup mechanism, the problem of signal conflict during multi-label concurrent work is effectively solved.

The invention provides an LED light output intelligent control method based on high-frequency driving, and relates to the technical field of intelligent control, and the method comprises the steps: applying a high-frequency detection pulse sequence with the same amplitude and increasing frequency to each lamp bead in an LED array, collecting the light response time constant and peak light intensity data of the lamp bead under the excitation of the detection pulse sequence, and obtaining the light response time constant and peak light intensity data of the lamp bead; and a frequency-light response feature vector matrix is constructed, and grouping management and distributed prediction control of the LED array are realized. According to the invention, the light response characteristic difference between the lamp beads is fully considered, and the accuracy and uniformity of light output control are improved; meanwhile, by establishing a distributed predictive control model, the optimal driving frequency and duty ratio parameter combination of each group can be predicted in real time, the problem of light response nonlinearity under the high-frequency driving condition is effectively solved, and the stability and efficiency of dynamic light output are improved.

The invention relates to a non-intrusive fast scanning identification method and system for MEMS resonant frequency, and belongs to the technical field of MEMS device detection.The method comprises the steps that an extremely-low-power broadband detection signal is emitted, a high-sensitivity receiver is used for capturing a weak harmonic wave or intermodulation response signal generated by coupling of the signal and a target MEMS device mechanical structure, and the weak harmonic wave or intermodulation response signal is obtained; after amplification and noise reduction preprocessing, a matched filtering or correlation analysis algorithm is adopted to process a response signal, the resonant frequency of the target MEMS device is rapidly and accurately extracted under the extremely low signal-to-noise ratio, and the whole recognition process does not interfere with normal work of the device. According to the method, a target device does not need to be contacted or interfered, the technical problems that a traditional MEMS resonant frequency identification method is high in invasiveness, low in signal-to-noise ratio, poor in identification precision and low in identification efficiency are solved, and the method has the advantages of being non-invasive, rapid in identification, high in precision and wide in adaptability and is suitable for resonant frequency detection scenes of various MEMS sensors and resonators.

The invention provides a hand tremor frequency detection method and system based on video analysis and machine learning and electronic equipment, and the method comprises the steps: obtaining a hand video, extracting a key point track, and generating a fusion track signal through principal component analysis; extracting a motion feature vector of the fusion signal, and predicting an optimal signal processing parameter for the current tremor mode by using a pre-trained machine learning model; and performing smooth filtering and frequency domain conversion on the original trajectory by using the parameter, thereby calculating the tremor frequency. According to the invention, the technical problems of insufficient slight tremor detection precision and weak anti-noise capability caused by the adoption of fixed signal processing parameters in the existing video analysis method can be solved.

The invention discloses a blood flow signal processing method and device based on silicon-based photons and wearable device.The method comprises the steps that firstly, phase modulation is conducted on three emitted narrow-band lasers with different wavelengths, the modulation frequency is set to be 50-100 MHz, and the generated sideband frequency is set to be 50-100 MHz; receiving a reflection signal passing through a human body artery blood vessel target area, demodulating the reflection signal and a local oscillator signal in a frequency mixer, and extracting a PDH error signal; finally, the blood flow direction in the target area is judged according to the positive and negative values. According to the hemodynamic monitoring system based on the optical resonant cavity array and the PDH read-out technology, through the innovation of a physical mechanism (strength detection is replaced by frequency detection), the innovation of a spatial architecture (an array replaces a single point) and the breakthrough of an algorithm model (physical field decoupling and waveform separation), the detection accuracy is improved; the problems that a traditional non-invasive blood pressure monitoring technology is low in precision, poor in interference resistance and lack of deep pathological information are fundamentally solved.

The invention provides a data co-processing method and device based on double-frequency RFID and electronic equipment, and relates to the technical field of clothing inventory management.The method comprises the steps that a pre-stored association mapping table of the double-frequency RFID is obtained; acquiring radio frequency signal data of the dual-frequency RFID acquired by the reader-writer; generating a differential feature vector according to the continuous time sequence signal; monitoring a statistical fluctuation value of the differential feature vector, inputting the differential feature vector in the corresponding time window into the neural network model when the statistical fluctuation value exceeds a preset wake-up threshold, and outputting a spatial behavior category; and when the discrete trigger signal is detected, searching a first frequency band identification code corresponding to the target object in the association mapping table, matching a spatial behavior category in a preset time neighborhood according to the trigger time of the discrete trigger signal, generating a data processing strategy based on the matched spatial behavior category and the first frequency band identification code, and sending the data processing strategy to the target object. Therefore, cooperative intelligent data processing of double-frequency detection is realized.

A phase-locked loop circuit includes a phase-frequency detector circuit, a time amplifier circuit, a control circuit, and a variable oscillator circuit, such as a voltage-controlled oscillator. The phase-frequency detector is configured to generate a phase error output indicating a phase difference between a reference signal and a feedback signal generated using an output signal. The time amplifier is configured to extend the phase difference to generate an extended phase error output. The variable oscillator is configured to use one or more control signals generated by the control circuit using the extended phase error to adjust a frequency of the output signal. The control circuit may generate a proportional control signal using a switched-resistor circuit that includes a pull-up resistor and a pull-down resistor. The control circuit may generate an integral control signal using a capacitive-shared-integration circuit that includes passive integrating components.

The invention provides a frequency detection circuit, a frequency detection method and an image sensor, and the circuit comprises a frequency conversion module which receives a clock signal, and converts the clock frequency of the clock signal into an analog electric signal, so as to carry out the detection of the clock frequency; wherein the frequency conversion module comprises a resistance acquisition unit, and the resistance acquisition unit receives a clock signal and converts the clock frequency of the clock signal into a clock resistance signal so as to acquire an analog electric signal. According to the frequency detection circuit, the frequency detection method and the image sensor provided by the invention, the problem that the reference time needs to be provided by an additional crystal oscillator in the existing frequency detection scheme is solved.

A phase-locked loop working system includes: a pre-frequency divider, a phase frequency detector, a charge pump, a filter, a voltage-controlled oscillator, a loop frequency divider and a circuit parameter regulator. The phase frequency detector, the charge pump, the filter, the voltage-controlled oscillator and the loop frequency divider are sequentially coupled end to end to form a phase-locked loop circuit. The circuit parameter regulator is coupled to the phase-locked loop circuit and is used to adjust a filtering resistor and a filter capacitor in the filter, to control loop parameters generated by the phase-locked loop circuit to be within a preset margin range. The circuit parameter regulator is coupled to the phase-locked loop circuit and is further used to adjust a frequency-division coefficient of the pre-frequency divider and / or a frequency of the signal to be processed inputted into the pre-frequency divider.

The invention relates to the technical field of digital clock signal processing, in particular to a clock frequency detection system and method based on clock edge alignment detection, and the system comprises a working state monitoring module, a sampling period counting module, a clock sampling module, a state judgment and change module, and an index generation and output module. A signal of the system in a normal working state is released through the working state monitoring module, a high-frequency clock signal is input to the working state monitoring module, and the system controls a sampling period through a low-frequency clock, periodically samples the high-frequency clock, counts the number of high levels in the sampling period and judges the state change of the high-frequency clock. And judging that the rising edge of the low-frequency clock is aligned with the rising edge of the high-frequency clock, and outputting a corresponding phase index value. The device is realized by adopting pure digital logic, has anti-jitter capability, can accurately identify the phase of the high-frequency clock, and has the advantages of simple structure, high precision and strong transportability.

An air cleaning system includes a housing having an inlet and an outlet, and a filter positioned within the housing, downstream of the inlet. A fan assembly is located within the housing. The fan assembly is in airflow communication with the filter. A sensor is positioned within the housing. The sensor is configured to monitor at least one of a particle size, an accumulation of dust on a surface of the filter, and a pressure drop over the filter. A result of a comparison between a measured dust level at the filter and a dust threshold is communicated to a user.

A phase frequency detector circuit, a method for generating a first output signal and a second output signal based on a reference signal and a feedback signal, and a phase-locked loop are provided. The phase frequency detector circuit includes a plurality of reference signals, a plurality of feedback signals, a first output signal, and a second output signal. The plurality of reference signals, including a primary reference signal having a reference triggering edge. The plurality of feedback signals, including a primary feedback signal having a feedback triggering edge. The first output signal and the second output signal indicating a phase difference between the primary reference signal and the primary feedback signal. The first output signal remains asserted after the primary feedback signal arrives, when the phase difference exceeds a max phase difference indicated by a difference between the primary reference signal and the reference signal.

This invention belongs to the field of touchscreen control technology, specifically relating to a control method and system for a capacitive touchscreen. The method involves initializing the capacitive touchscreen, setting the driver IC's operating mode, and transmitting configuration register settings. An AC signal is emitted from the X-axis electrode, and a signal is sensed by the Y-axis electrode. Capacitance is determined by detecting charging time. Touch actions are identified by utilizing the characteristic that finger touch changes capacitance. The X-axis is controlled to sequentially emit excitation signals, while the Y-axis receives them synchronously to detect the magnitude of mutual capacitance. Touch point coordinates are calculated based on a two-dimensional capacitance change data table. A dynamic threshold adjustment and multi-frequency alternating detection process are implemented. The dynamic threshold adjustment updates the baseline threshold according to environmental changes, and multi-frequency detection eliminates electrostatic interference. This invention dynamically adapts to environmental changes, has strong anti-interference capabilities, balances detection efficiency and accuracy, and can handle complex touch scenarios, improving the reliability and user experience of touchscreens in various application scenarios.

The invention particularly relates to a multi-dimensional suppressing interference rapid interception response signal processing method, which comprises the following steps of: setting energy and frequency detection after echo sampling, setting energy and frequency detection after digital down-conversion, setting signal feature detection after pulse compression and moving target indication, and setting statistical detection after CFAR (Constant False Alarm Rate) detection. Signal feature detection is set after moving target detection and SAR imaging. And based on the score of each detection module, control enabling of different priorities on the anti-interference function of the system, including an immediate dimension, a short-time dimension and a long-time dimension, is generated, so that the aim of rapidness is fulfilled. According to the method, the suppression interference is accurately and quickly identified in combination with the judgment standards of multiple dimensions, the anti-interference response is carried out at the fastest speed, and the anti-interference response is carried out at the fastest speed. The application can be well embedded into a conventional radar signal processing system, has the characteristics of strong universality, good real-time performance and high accuracy, and can be widely applied to the field of digital signal processing products.

The application discloses a kind of frequency guidance-based array signal space-frequency information fusion processing method and device, applied to field programmable gate array (FPGA), by obtaining the multiple array signals for carrying out target detection received by target radar array;Any one of the multiple array signals is subjected to frequency detection, and at least one target frequency value is obtained;At least one target frequency value is subjected to frequency conversion filtering according to the multiple array signals, and at least one target array signal corresponding to at least one target frequency value is obtained;At least one target array signal is subjected to angle of arrival estimation, and at least one angle of arrival is obtained;According to at least one target frequency value and at least one angle of arrival, the corresponding relationship of target frequency value and angle of arrival is determined.The application utilizes single-channel signal to carry out frequency measurement, and then carries out filtering processing to multiple array signals and carries out angle of arrival estimation, and subsequent frequency retrieval is not necessary, and the FPGA resource utilization is improved.

The invention relates to the technical field of industrial combustion control, and discloses a boiler ignition device self-adaptive regulation and control system fusing multi-source sensing data. Comprising a multi-source heterogeneous data acquisition and synchronization module, a flow field phase space reconstruction and feature extraction module, an electrode gap impedance spectroscopy inversion module, a flow-electric frequency domain resonance avoidance and parameter calculation module and a variable frequency pulse modulation and execution module. Analyzing the flow field stability and the turbulence dominant frequency by using a nonlinear dynamics algorithm, and inverting the flammability of the medium through sweep frequency detection; and determining a carrier frequency avoiding a turbulent resonance band through frequency domain orthogonal screening, and carrying out decoupling calculation on a duty ratio and a voltage gain adaptive to the current working condition. The ignition strategy can be adaptively adjusted according to the transient flow field structure and medium characteristics, arc extinguishing caused by flow field pulsation is effectively avoided, and the ignition stability and success rate under the complex working condition are remarkably improved.

The invention discloses a quick-access low-voltage transfer box, and relates to the technical field of low-voltage transfer boxes, and the quick-access low-voltage transfer box comprises a mains supply main supply module which is used for accessing mains supply electric energy; the mains supply standby module is used for being connected with the generator car and accessing standby electric energy; the phase sequence detection module is used for transmitting commercial power and detecting voltage, phase and frequency by the generator car; the switch switching module is used for controlling the transmission state of the mains supply electric energy and the standby electric energy; and the indication module is used for illumination. Compared with the prior art, the system has the beneficial effects that a standardized interface and control point are provided, clear switches such as a mains supply standby switch, a mains supply main supply switch and a mains supply disconnecting link are arranged, through a strict instruction sequence, the power generation vehicle and the mains supply are ensured to be synchronized in voltage, frequency and phase, and then load transfer is carried out; therefore, impact on a power grid and power generation equipment is avoided to the greatest extent, and operation safety and power supply stability are guaranteed.

The invention provides an audio output sampling rate calculation method and device, electronic equipment and a storage medium. The method is applied to an audio playing system, and comprises the following steps: in an audio data playing process of an audio buffer area, detecting a filling level of the audio buffer area according to a preset detection frequency; wherein the filling level is used for indicating the current data volume of the audio buffer area; based on the filling level, first clock skew corresponding to the recent multiple detection periods is obtained, and a clock skew set is obtained; calculating a first clock calibration amount according to a first clock skew corresponding to the current detection period in the clock skew set; performing clock drift trend prediction on the clock skew set, and determining a second clock calibration amount according to a prediction result; and according to the first clock calibration amount and the second clock calibration amount, determining the sampling rate of at least one frame of audio data output audio buffer in the future. The method and the device are used for carrying out real-time, accurate and self-adaptive clock calibration on audio playing.

The application provides a flash fusion frequency detection device for objective measurement of human fatigue state, which at least comprises: the flash fusion frequency detection device (1) is integrated with a power line, a flash device (2) arranged on the surface of the flash fusion frequency detection device (1), and a detection result selection device (3) internally integrated with a flash frequency control module, a communication module, a storage module, a data processing module and a fatigue judgment module, and the fatigue condition of a detected person is determined through the judgment process of the data processing module and the fatigue judgment module under different conditions. The device can effectively prevent the subjective cheating behavior of the testee when detecting the flash fusion frequency of the human body, can finely manage the detection process, and can effectively reduce the deviation of the detection result caused by the misoperation of the detected person.