1729 results about "Low pass filtering" patented technology

The invention relates to the field of target detection, in particular to a UMFNet-YOLO-based joint detection algorithm under a low-light condition, which adopts a multi-scale decomposition and high-frequency-low-frequency feature collaborative enhancement strategy, separates image details from global features through high / low-pass filtering, realizes multi-resolution feature complementation in combination with dynamic weight distribution, and improves the detection accuracy. Target contour and texture information degraded in severe weather can be effectively recovered; a parallel channel compression and spatial semantic enhancement module is designed, rain and fog noise interference is suppressed through cross-dimensional adaptive feature screening, and significance expression of a key target is enhanced; an image enhancement network UMFNet is cascaded with YOLOv8, and strong correlation between feature expression and a detection task is ensured by synchronously optimizing an enhancement module and detecting network parameters through back propagation. Compared with a baseline YOLOv8 detector, the method has the advantages that the average precision (mAP50) is obviously improved, and the method is obviously superior to a traditional enhancement-detection separation scheme. The method can be applied to robust target detection scenes in complex environments such as automatic driving and security monitoring.

The invention provides a diffractive optical element design and manufacturing integration method based on gray level laser direct writing photoetching, which comprises the following steps that: a manufacturing simulator and a wave optical simulator are established, and the manufacturing simulator represents the spatial frequency response of an optical system through a low-pass filtering model; a mapping relation between exposure dose and a developing result is established by combining nonlinear response of photoresist, and the wave optical simulator predicts optical performance by utilizing output of the manufacturing simulator and combining a wave optical theory; by setting initial manufacturing parameters and performing iterative optimization, the surface appearance of the photoresist is dynamically adjusted to be close to the target optical performance, the optimization process is combined with an automatic differential technology, a gradient optimization algorithm and a block optimization strategy, and the calculation efficiency is improved; and the optimized parameters are used for processing gray laser direct writing equipment to manufacture the diffractive optical element. The problem of manufacturing deviation caused by the optical proximity effect in the prior art can be solved, and meanwhile the overall performance of the diffraction optical element is remarkably improved.

A method for extracting a wear particle feature signal based on segmentation entropy is provided, including obtaining a raw signal to be processed by performing real-time data acquisition using a lubricating oil wear particle monitoring system; obtaining a preprocessed signal by performing low-pass filtering and harmonic interference suppression on the raw signal to be processed; dividing the preprocessed signal into a plurality of time domain sequence segments with a sliding window; calculating segmentation entropy corresponding to each time domain sequence segment, normalizing a segmentation entropy set to obtain normalized segmentation entropy; obtaining an adaptive threshold through curve fitting based on empirical cumulative distribution of normalized segmentation entropy, obtaining a plurality of non-zero discrete time domain signal segments by segmenting the preprocessed signal by the adaptive threshold; and obtaining final extraction results of the wear particle feature signal by excluding residual noise interference through target signal feature recognition indices.

The invention relates to the technical field of steel truss assembly precision control, and discloses a large-space steel truss assembly construction precision control method based on a real-time monitoring technology. According to the method, through a sensing technology and a data processing system, steel truss supporting node coordinates, strain force and material temperature data are collected in real time and transmitted to a data processing center through a wireless network to be subjected to low-pass filtering and stress and thermal expansion calculation, and therefore it is ensured that the material state meets the assembling standard; error calculation and precision evaluation in the process not only can timely discover and correct deviation, but also can feed back to the assembling and adjusting equipment through intelligent signals to realize automatic precision control, and compared with traditional manual measurement, the method has the advantages that the influence of environmental factors on measurement accuracy is greatly reduced, the limitation of static measurement is overcome, and the measurement accuracy is improved. And real-time monitoring and correction capabilities are provided, so that structural deformation and safety risks are reduced, and the overall construction quality and safety of the steel truss are ensured.

The invention provides a PPG big data driven biological feature recognition method, which comprises the following steps: acquiring PPG signal data of trainees, and performing high-pass filtering and low-pass filtering preprocessing on the PPG signal data to obtain preprocessed PPG signals; framing is carried out on the preprocessed PPG signal, a Mel frequency cepstral coefficient feature and a Gammatone frequency cepstral coefficient feature are extracted respectively, the Mel frequency cepstral coefficient feature and the Gammatone frequency cepstral coefficient feature are fused, then principal component analysis dimension reduction is carried out, and a fusion feature is obtained; a universal background model UBM of a Gaussian mixture model is constructed based on the fusion features, zero-order, first-order and second-order Baum-Welch statistics are calculated, a global difference space matrix is estimated from the Baum-Welch statistics, and i-vector identity authentication vectors are extracted; and inputting the i-vector identity authentication vector into a long short-term memory network for training and classification to obtain an identity recognition result of the trainees. According to the invention, the influence of motion artifacts can be eliminated, the overall variability of PPG signals is captured, and an identity authentication scheme is provided for wearable equipment.

The invention discloses a control system and method for a thermal power generating unit and flywheel energy storage to cooperatively participate in power grid frequency modulation and a power grid frequency modulation method. According to the method, a low-pass filtering algorithm is abandoned, a tracking differentiator is used for decomposing a primary frequency modulation instruction of the thermal power generating unit, and decomposed low-frequency power components are distributed to the thermal power generating unit; high-frequency power components are distributed to the flywheel for energy storage, action times and output abrasion of the thermal power generating unit are reduced, and the service life of the unit is prolonged. A gain coefficient which adaptively changes along with the state of charge (SOC) and frequency deviation is introduced into the decomposed high-frequency power component, so that accurate matching requirements are facilitated, the energy utilization efficiency is improved, the frequency fluctuation of a power grid is better stabilized, and the quality of the power grid is improved; and meanwhile, a Logistic function for preventing the flywheel from being overcharged and overdischarged is introduced to restrain the theoretical response power of flywheel energy storage, deep charging and discharging of the flywheel are avoided, and therefore the loss of the flywheel is reduced.

A method performed in an encoder for selecting a coding mode for a current frame includes obtaining bit rates for absolute coding and predictive coding. The method includes calculating a bit rate difference based on the bit rates obtained. The method includes low-pass filtering the bit rate difference. The method includes selecting a coding mode based on the bit rate difference, the low-pass filtered bit rate difference, and a predictive mode counter.

The invention relates to an underwater cleaning robot positioning and tracking method. Positioning comprises the steps that data of multiple sensors on an underwater cleaning robot are fused through an extended Kalman filter, and coordinates of the underwater cleaning robot on the surface of a ship body are obtained after sensor measurement noise is filtered through a first-order low-pass filtering algorithm. The tracking method comprises the step of realizing the path tracking of the underwater cleaning robot based on the positioning method in combination with an iterative linear quadratic regulator (ILQR). According to the invention, a multi-sensor fusion scheme of the encoder, the IMU and the depth meter is innovatively provided, and the positioning problem of the underwater cleaning robot in a wall attaching state is solved. And double-plane differential treatment is adopted, so that the working state of the robot on the ship wall or the ship bottom is better fitted, and positioning is more accurate. A target point updating mechanism of geometric distance constraint is provided, the nearest neighbor point of the reference trajectory is adjusted in real time, and the problem of tracking lag caused by updating rate mismatch in a traditional method is solved.

The invention discloses an optimal control method for target boost pressure, which comprises the following steps of: entering boost closed-loop enabling under the condition that boost closed-loop enabling conditions are met, and obtaining a filtered EGR rate characteristic coefficient after first-order low-pass filtering according to filtering time and an EGR rate characteristic coefficient; according to the currently disclosed target supercharging pressure, the EGR rate characteristic coefficient and the filtering EGR rate characteristic coefficient, the target supercharging pressure which is not dynamically optimized is obtained through calculation; dynamically optimizing the target supercharging pressure which is not dynamically optimized according to the actual supercharging pressure read in real time to obtain the dynamically optimized target supercharging pressure; and controlling a supercharging actuator according to the dynamically optimized target supercharging pressure. According to the method provided by the invention, optimal control on the target supercharging pressure can be realized, and the supercharging closed-loop control stability and the EGR response precision are further improved.

The invention discloses an arm movement monitoring and health recognition method and system based on a wearable sensor. The method comprises the steps that original multi-axis signals in the arm movement process of a user are collected; carrying out analysis, calibration and low-pass filtering on the original multi-axis signal, and calculating a three-dimensional attitude angle and a motion track of an arm in real time by adopting an improved Kalman filtering algorithm; segmenting the continuous motion data into a standardized motion sequence by adopting a hybrid motion segmentation algorithm; performing time-frequency domain analysis on the standardized action sequence to obtain a time domain feature and a frequency domain feature; extracting attitude track features; the time domain features, the frequency domain features and the attitude track features are combined into a high-dimensional feature matrix, and low-dimensional feature vectors are generated after dimension reduction; and inputting the low-dimensional feature vector into a pre-trained health assessment model, and outputting an arm motion function score, abnormal type early warning and rehabilitation guidance. The system can realize remote guidance of doctors and household rehabilitation monitoring of patients, and has the advantages of high precision, low cost and high real-time performance.

The invention discloses an MT-InSAR deformation monitoring method in combination with reservoir bank landslide deformation spatial-temporal characteristics. The method comprises the following steps: S1, selecting SAR data; step S2, constructing small baseline set InSAR data, including SAR image registration, interferogram combination, differential interference processing, phase filtering, coherence estimation and interferogram optimization combination; s3, based on the dual-polarized SAR intensity image, performing earth surface classification in combination with random forest classification, gradient and direction constraint and a deep neural network; then adaptive homogeneous filtering is carried out on the interferometric phase based on a secondary classification result; s4, combining a plurality of Sigmoid functions and a linear creep and periodic function to obtain an adaptive deformation model of the reservoir bank landslide; s5, performing deformation parameter nonlinear search by using a genetic algorithm to determine an optimal parameter set; on the basis of low-frequency deformation, atmospheric delay and decoherence noise are separated through low-pass filtering of a space domain and high-pass filtering of a time domain, and finally a deformation time sequence and an average deformation rate are recovered.

The invention discloses a photovoltaic equipment networking control method and system, and relates to the technical field of photovoltaic power generation, when the system runs, a data acquisition module ensures high-precision current signal acquisition, and a digital signal processing module removes noise and enhances signal quality through low-pass filtering and convolution operation; the signal conversion module comprehensively analyzes frequency spectrum information by using FFT (Fast Fourier Transform), and the data analysis module extracts harmonic components, calculates a total harmonic distortion rate THD and provides an accurate filter adjustment scheme; the regulation and control module calculates a power factor Pf and a flash variable Fb, comprehensive power quality evaluation is carried out in combination with THD, it is ensured that the system operates in the optimal state, and the system effectively solves the problems that in traditional photovoltaic equipment networking, current signal collection precision is low, signal processing is unstable, harmonic distortion is difficult to monitor, and power quality is difficult to comprehensively evaluate. And the power output quality of the photovoltaic equipment and the reliability and economic benefits of the whole power system are remarkably improved.

The invention relates to the technical field of power electronics, in particular to an inverter load feed-forward compensation method and system based on dynamic hysteresis regulation. The method comprises the following steps: acquiring an instantaneous load current signal of an inverter system; wherein when the load current suddenly changes, the bus voltage on the direct current bus fluctuates; performing low-pass filtering on the instantaneous load current signal to extract a direct current component of the load current; determining a dynamic hysteresis limit value according to the instantaneous load current signal, the direct current component and the amplitude adjustment coefficient; comparing the instantaneous load current signal with a historical current feed-forward signal, updating the historical current feed-forward signal according to a comparison result and a dynamic hysteresis limit value, taking the updated historical feed-forward current signal as an updated feed-forward current signal of the current control period, generating a compensation current based on the updated feed-forward current signal, and outputting the compensation current to the current control period. And the compensation current is applied to the corresponding direct-current bus so as to suppress bus voltage fluctuation caused by load abrupt change.

The invention relates to the technical field of data cleaning processing, in particular to a big data cleaning method based on deep learning and data feature matching, and the method comprises the following steps: constructing a three-dimensional electromagnetic pollution topological map through an electromagnetic fingerprint spectrum generator; anti-interference cleaning channels are activated according to dynamic changes of the electromagnetic pollution topological map, and each channel generates a channel configuration instruction set; receiving a channel configuration instruction set, executing dual operations of data pulse waveform reconstruction and feature restoration, and outputting a restored clean data block; and writing back the clean data block to the original storage medium. According to the method, accurate recovery of pulse distortion caused by electromagnetic interference is achieved, and compared with a traditional method based on low-pass filtering or interpolation recovery, nonlinear interference components can be more effectively removed, data signal integrity is ensured, and the fidelity of recovered data is improved.

The invention relates to the technical field of inverter power control, and discloses a given current-based inverter power control method and system, and the method comprises the steps: calculating a fluctuation compensation parameter based on a bus voltage, and carrying out the real-time compensation of a q-axis basic current, and obtaining a first given q-axis current; predicting the bus voltage of the next period and correcting the first given q-axis current in advance to obtain a second given q-axis current; on the basis of the stator voltage saturation state, weak magnetic d-axis current given is generated, low-pass filtering is carried out on the second q-axis current given and the weak magnetic d-axis current given, and a d-axis current instruction and a q-axis current instruction are obtained; a PWM driving signal corresponding to a dq-axis current instruction is generated, an inverter switch is controlled, meanwhile, a power deviation signal is collected to update q-axis basic current, accurate prediction of bus voltage and advanced correction of given current are achieved, compared with traditional lag compensation, the dynamic response is faster, and the power control precision and the operation stability are improved.

The invention provides an anti-interference sound signal data extraction method based on energy data perception, and belongs to the technical field of underwater sound signal processing, and the method comprises the steps: carrying out the A / D sampling and digital orthogonal demodulation of a received sound signal, and obtaining a baseband signal; performing low-pass filtering and downsampling on the baseband signal to obtain a preprocessed signal; performing matched filtering on the pre-processed signal by using a reference signal; the key improvement lies in that a local energy estimation function of a preprocessed signal is calculated, and normalization processing is carried out on a matched filtering result and the energy estimation function to obtain a normalized detection signal. The method effectively suppresses the shielding effect of a strong interference signal on a weak target signal under a non-orthogonal reference signal and a strong near-end and weak far-end scene, remarkably reduces the misrecognition probability, and improves the accuracy and reliability of the extraction of a long-distance and low-signal-to-noise-ratio target beacon signal in a complex underwater acoustic environment. The method is suitable for underwater navigation, positioning and communication systems.

The invention discloses a real-time power generation load estimation method and system for photovoltaic power generation, relates to the technical field of photovoltaic power generation load estimation, and aims to solve the problems of state judgment delay and model mismatching and misestimation caused by short-time cloud shadow rapid movement. The method comprises the following steps: collecting power, current, voltage, irradiance and temperature signals through a multi-array sensor, separating a high-frequency characteristic signal from a low-frequency characteristic signal through high-pass / low-pass filtering, and generating a static baseline multi-dimensional characteristic vector; based on the power spectrum entropy, adaptively adjusting a time window and extracting dynamic characteristics; fusing the static and dynamic characteristics to generate discrimination input; performing state judgment by adopting a logistic regression model, and starting extended Kalman filtering online correction when an energy residual exceeds a threshold; and model drift is detected based on CUSUM and Shewhart algorithms, and an incremental training set is automatically constructed to update model parameters. And high-precision and low-delay real-time power generation load estimation and operation and maintenance support under a short-time cloud shadow condition are realized.

The invention discloses a permanent magnet synchronous motor current dynamic coupling correction method, which comprises the following steps of collecting motor three-phase stator current, performing Clark transformation to obtain a current value under an alpha-beta static coordinate system, and meanwhile, collecting through a position sensor to obtain an electrical angle true value; performing low-pass filtering calculation on the current value under the alpha-beta static coordinate system to obtain a filtering current value, and performing operation through a sliding-mode observer and a PLL phase-locked loop to obtain an electrical angle observation value; calculating to obtain a compensation adjustment coefficient according to the true value and the observed value of the electrical angle, and further calculating to obtain a current value after phase offset compensation; and performing complementary filtering calculation on the filtering current value and the current value after phase offset compensation to obtain a coupling correction current value for current loop calculation, inputting the coupling correction current value into a motor control current loop PID algorithm, and generating a PWM driving signal to drive a motor in combination with vector control. According to the method, the problems of high-frequency interference and phase deviation of current sampling can be solved, so that the motor control efficiency and the dynamic performance are improved.

The invention discloses an underwater three-dimensional reconstruction method and system and a storage medium, and the method comprises the steps: estimating a camera posture from a given image sequence through employing an SFM, and constructing a 3D sparse point cloud; circularly rendering underwater scenes of different camera postures by using 3DGS, initializing 3D sparse point clouds to obtain 3D Gaussian point clouds, and representing a rendered image corresponding to each camera posture through a group of 3D Gaussian point clouds; when a rendered picture is output through 3DGS cyclic rendering every time, calculating a residual error between the rendered picture and an input image in the image sequence, performing Fourier transform on the residual error, removing a high-frequency signal by using a low-pass filter, performing inverse Fourier transform on a reserved part, and optimizing all parameters of each Gaussian point by using parameters after inverse Fourier transform, so as to obtain a rendered picture; and inputting the 3D Gaussian point cloud after optimization of each Gaussian point back to circulating rendering of the 3DGS. A low-pass filtering technology is used in a 3DGS iteration process to construct a three-dimensional scene representation with consistent illumination, and ghost shadows are removed from the three-dimensional scene representation so as to recover a scene with uniform illumination.

The invention relates to a panchromatic sharpening method and system based on a high-frequency difference space attention mechanism, and the method comprises the steps: carrying out the modeling of a low-resolution multispectral LRMS image into a space degradation version of a high-resolution multispectral HRMS image, obtaining a spectrum fidelity term, generating an attention injection weight map through an attention injection module, and carrying out the processing of a spectrum fidelity term. Respectively inputting the panchromatic PAN image and the low-pass filtering image into a difference attention book module to calculate to obtain a high-frequency difference attention graph, then constructing a high-frequency difference space fidelity term according to an attention injection weight graph and the high-frequency difference space attention graph, and introducing a logarithm nuclear norm of a high-resolution multispectral HRMS image to obtain a high-resolution multispectral HRMS image; according to the method, a spectral fidelity term is combined with a high-frequency differential space attention space fidelity term and a tensor low-tube-rank constraint term, a panchromatic sharpening algorithm mathematical model is built, finally, a substitution direction multiplier method is adopted to carry out optimization solution on the mathematical model, and finally, a high-resolution multispectral HRMS image result is output.

The invention provides a three-phase single-stage isolation rectifier and a power factor correction method thereof, and belongs to the technical field of switching power supplies. The three-phase single-stage isolation rectifier comprises a low-pass filtering unit, a sector selection unit, a DC / DC high-frequency conversion unit and a compensation conversion unit, wherein the low-pass filtering unit is connected with a three-phase alternating current, and the DC / DC high-frequency conversion unit is connected with a direct-current load; the sector selection unit comprises a first bridge circuit and a switching circuit, the compensation conversion unit comprises a power frequency switching unit and a high-frequency converter, the first input end of the power frequency switching unit is connected with a first terminal P, the second input end of the power frequency switching unit is connected with a third terminal Y, the third input end of the power frequency switching unit is connected with a second terminal N, and the second input end of the power frequency switching unit is connected with a third terminal Y; the output end of the power frequency switching unit is connected with the output end of the high-frequency converter, the first input end of the high-frequency converter is connected with the first terminal P, and the second input end of the high-frequency converter is connected with the second terminal N. The conversion efficiency of the isolation rectifier can be improved.

The invention discloses a method for detecting and displaying the electric quantity of an earphone, which relates to the technical field of electronic equipment and comprises the following steps of: acquiring an analog signal of battery voltage through an ADC (analog-to-digital converter) channel, converting the analog signal into a digital signal, performing digital filtering processing on the acquired signal, matching a preset voltage-electric quantity mapping table according to an updated battery voltage value, and displaying the electric quantity of the earphone according to the preset voltage-electric quantity mapping table. According to the method for detecting and displaying the electric quantity of the earphone, the voltage of a lithium battery of 0-4.2 V is detected through an ADC differential input mode, the sampling frequency is 100-500 Hz, the precision is 10-12 bits, and signal stability is ensured through low-pass filtering. A sliding window mean filtering algorithm is adopted to process signals, fluctuation and noise are effectively eliminated, and voltage changes are dynamically tracked. A deviation comparison mechanism avoids misjudgment and ensures accurate electric quantity detection. The electric quantity mapping table is dynamically adjusted according to the voltage, the battery use duration and the environment temperature, the earphone electric quantity state is accurately reflected, the user experience is improved, and the electric quantity detection stability and accuracy are improved.

The invention discloses a chip reference voltage trimming circuit which is characterized in that when an enable signal is in a high level, a low enable discharge module is turned off, and an adjustable buffer unit generates a preset voltage according to an external reference voltage and a voltage regulating signal; the generated preset voltage generates a reference voltage after passing through a low-pass filtering network consisting of a fast charging path, a slow charging path and a filtering capacitor; the abnormal state detection unit is used for detecting the abnormity of the trimming circuit, if abnormity exists, the output signal of the abnormal state detection unit is high level, the output signal of the quick charging control unit is controlled to be low level, the quick charging access is opened, and the opening time of the quick charging access is controlled through the quick charging control unit; and a following speed trimming signal is input to the fast charging control unit, and the generated reference voltage is trimmed to be the same as the preset voltage. The performance of the reference voltage of the chip is adjusted through the trimming signal, and the performance requirements of equipment in different working states can be met.

The invention discloses an ultra-wideband 6-bit numerical control attenuator with low attenuation amplitude error and low phase change. The digital attenuator is composed of six attenuation units of 0.5 dB, 1 dB, 2 dB, 4 dB, 8 dB and 16 dB. The attenuation units are cascaded according to the attenuation amounts of 0.5 dB, 4dB, 16dB, 8dB, 2dB and 1dB, the attenuation units with the attenuation amounts of 0.5 dB and 1dB adopt a simplified T-shaped structure, the attenuation unit with the attenuation amount of 2dB adopts a bridge T-shaped structure, the attenuation unit with the attenuation amount of 4dB adopts a pi-shaped structure with bypass capacitance compensation, and the attenuation unit with the attenuation amount of 8dB adopts a pi-shaped structure with a bypass compensation capacitor and a branch communication compensation capacitor. And the attenuation unit with the attenuation amount of 16dB is formed by cascading two improved 8dB SPDT switch path type attenuation units. According to the invention, reverse compensation is carried out on phase lag caused by a low-pass filtering network formed by a reference state of a traditional attenuation structure or phase lead caused by a high-pass filtering network formed by an attenuation state, so that the phases of the two are close, and the phase difference between the reference state and the attenuation state is greatly reduced.

The invention relates to the technical field of impurity gas detection control, and discloses an impurity detection control method and system for high-purity oxygen, and the method comprises the steps: arranging a plurality of groups of TDLAS detection probes and temperature vibration monitoring units, and obtaining a spectrum harmonic signal and temperature and vibration data; the concentration is inverted through wavelength modulation spectrum demodulation and temperature and pressure disturbance compensation; pCA fusion denoising processing is executed through the edge calculation unit, and correction concentration is output; and abnormity is judged through a multi-scale dynamic threshold mechanism and linkage control is carried out. Compared with a common single-point probe or traditional low-pass filtering in the prior art, the technical problem that interference between impurity concentration change and environmental disturbance cannot be effectively handled especially in a high-vibration and high-temperature-difference environment is solved. According to the invention, through multi-channel cooperative weighting, PCA fusion compensation and a dynamic threshold determination mechanism, accurate detection control of the high-purity oxygen conveying pipeline in an industrial environment is realized, and the automation level of pipeline impurity gas detection control is improved.

The invention discloses an AC excitation system rotor initial position on-line identification method and system, and the method comprises the steps: collecting a stator three-phase voltage signal when a stator is no-load, carrying out the Clarke conversion of the signal, obtaining a voltage component under a static coordinate system, and carrying out the low-pass filtering processing; calculating a stator flux linkage based on the stator current and the processed voltage component, and calculating a rotor flux linkage based on the rotor current; the rotor initial position offset is continuously accumulated through closed-loop adjustment by calculating the stator and rotor flux linkage angle and the phase difference until the phase difference approaches zero, and the accumulated rotor initial position offset is output; and combining the mechanical angle output by the encoder with the accumulated rotor initial position offset to obtain a corrected rotor position angle, and updating the corrected rotor position angle to an excitation system. According to the method, the in-phase characteristics of stator and rotor flux linkages are utilized, and the optimally designed low-pass filter is combined, so that the identification precision of the initial position of the rotor is remarkably improved, and the zero offset of the encoder is effectively compensated.

The invention discloses a dither signal filtering and sampling method based on a TFLN laser. The method comprises the following steps: step 1, loading a fundamental wave / second harmonic of a low-frequency dither signal into a photo-generated current of an optical module; 2, the photo-generated current signal loaded with the fundamental wave / second harmonic of the dither signal is amplified through an operational amplifier circuit and then is divided into two paths to be output; 3, after the first path of output in the two paths of output passes through a low-pass RC filter circuit, optical power sampling is carried out to monitor optical power, and the second path of output in the two paths of output is divided into a fundamental wave branch and a second harmonic wave branch; 4, enabling the fundamental wave branch and the second harmonic wave branch to pass through a corresponding frequency-selecting filtering and amplifying circuit and a rear-end amplifying and biasing circuit respectively to obtain a fundamental wave signal and a second harmonic wave signal, and outputting the fundamental wave signal and the second harmonic wave signal to an ADC sampling module for sampling. According to the invention, effective sampling of the fundamental wave and the second harmonic wave of the dither is realized.

The invention discloses a millimeter wave detector suitable for a short-distance moving target. The millimeter wave detector comprises a millimeter wave front end and an intermediate frequency signal processing unit, wherein the intermediate frequency signal processing unit comprises a low-pass filtering and amplifying circuit which is used for realizing low-pass filtering of a first preset frequency; comprising a detection circuit which is used for outputting an envelope signal of a second preset frequency and filtering a triangular wave signal of a third preset frequency; the band-pass filtering and amplifying circuit is used for realizing band-pass filtering between a fourth preset frequency and a fifth preset frequency; and the signal peak threshold judgment circuit is used for judging whether a detection target appears in a distance range needing to be detected or not according to the signal output by the band-pass filtering and amplifying circuit. The millimeter wave detector suitable for the short-distance moving target has the beneficial effect that the short-distance target detection sensitivity can be effectively improved.

The utility model relates to an anti-pinch detection circuit and a motor device, the anti-pinch detection circuit comprises a sampling circuit, a differential amplification circuit, a ripple signal conversion circuit, a low pass filter circuit and a controller, the sampling circuit samples a ripple current signal of a vehicle window motor to obtain a corresponding voltage sampling signal, and the voltage sampling signal is sent to the differential amplification circuit; the differential amplification circuit carries out differential amplification on the voltage sampling signal to obtain a voltage amplification signal, the voltage amplification signal is divided into two paths, one path is converted into square wave signals through the ripple signal conversion circuit, the controller determines the position of a car window according to the number of the square wave signals, and the other path is subjected to low-pass filtering through the low-pass filtering circuit to obtain the voltage amplification signal. If the position of the car window is located in the preset anti-pinch area, the controller determines whether the car window is locked or blocked or not according to the amplitude of the low-frequency ripple signal. The anti-pinch detection circuit adopts two-path detection, so that the influence of environment or other factors on the ripple current signal is avoided, further anti-pinch misjudgment is avoided, and the anti-pinch detection accuracy is improved.

The invention provides a coaxial shunt capable of preventing high-frequency radio frequency leakage, which comprises an outer conductor, a resistor body and a central shaft conductor, the central shaft conductor and the outer conductor are respectively provided with a central shaft conductor signal output end and an outer conductor signal output end, and a low-pass filtering module is arranged in a cylindrical structure of the resistor body. And the low-pass filtering module is electrically connected with the central shaft conductor signal output end and the outer conductor signal output end. According to the coaxial shunt capable of preventing high-frequency and radio-frequency leakage provided by the invention, the low-pass filtering module is arranged between the signal output end of the central shaft conductor and the signal output end of the outer conductor, so that leaked high-frequency and radio-frequency signals can be filtered, and the detection bandwidth of the coaxial shunt capable of preventing high-frequency and radio-frequency leakage is effectively increased; and the space is saved. The invention also provides a current detection system.