57results about How to "Filter out noise" patented technology

The invention relates to the technical field of meteorological monitoring and lightning protection, and discloses a radio signal-based lightning protection detection method for a meteorological station, which comprises the following steps of: receiving electromagnetic wave signals generated by lightning discharge in real time through radio receiving equipment of a plurality of meteorological stations, and acquiring characteristic data of time, frequency and intensity of the signals; an effective light velocity model is adopted to correct the influence of the propagation velocity of the lightning signal in the atmosphere, and the effective propagation velocity of the lightning signal is calculated by considering the ionospheric and atmospheric refraction effects; the position of the lightning power supply is estimated by measuring the arrival time difference and the time difference of lightning signals received by different sites and utilizing the geometric positions of the multiple sites. The positioning precision of the lightning power supply is greatly improved by adopting the cooperative work of the radio receiving equipment of a plurality of meteorological stations and combining the technologies of accurate lightning signal propagation speed correction, time synchronization error correction, geometric precision optimization and the like.

The invention provides a marine photovoltaic energy storage inverter, which relates to the technical field of marine equipment and comprises a photovoltaic cell panel DC1, a storage battery DC2, a direct current filtering module, a boosting module, an inversion module, an alternating current filtering module and a control module. The photovoltaic cell panel DC1 and the storage battery DC2 serve as direct current input and are connected with the direct current filtering module, the direct current filtering module is connected with the boosting module, the boosting module is connected with the inversion module, the inversion module is connected with the alternating current filtering module, and the alternating current filtering module is connected with the control module. According to the invention, the design of double direct current filtering units is adopted, the interference of the input ends of the photovoltaic cell panel DC1 and the storage battery DC2 is effectively filtered, and the purity and stability of the marine direct current are ensured.

The present invention provides a high-voltage low-pass filter, comprising: a reactor and a capacitor, wherein the high-voltage low-pass filter is a low-pass filter of a voltage level of 100 kV or above. The high-voltage low-pass filter also includes a voltage grading ring, which is located at the top of the high-voltage low-pass filter and between the reactor and the capacitor of the high-voltage low-pass filter to reduce the electric field strength on the surface of the high-voltage electrode. The present invention also provides a method for designing a high-voltage low-pass filter.

The invention discloses a subway shielding door safety detection system based on laser ranging and a human body detection method, and the system employs an infrared laser ranging sensor which is disposed at the top between a shielding door and a vehicle door, projects an infrared laser beam from top to bottom, and forms a light spot on the surface of a target. The distance information between the light spot and the detector is obtained in real time, intelligent judgment is carried out, whether a target appears or not is recognized, and an alarm is given immediately after the target is found. The detection system can directly output an alarm signal, and further processing of an upper computer is avoided. The optical-mechanical-electrical integration technology is adopted, the size is small, the occupied space is small, and installation, debugging and maintenance are all very convenient. Based on a mature laser triangulation ranging technology and a laser displacement sensor product technology, the method has the advantages of low cost and less investment. A serial bus is adopted for multi-point cascade connection, one cable can be connected with all detection systems, the hardware cost is extremely low, and distributed networking is very simple.

The invention discloses a silicon carbide intelligent power module with voltage and current dual-detection over-current protection, and relates to the technical field of semiconductors. In order to solve the problem that when an existing silicon-based intelligent power module (IPM) is matched with a silicon carbide metal-oxide-semiconductor field effect transistor, due to the fact that the over-current protection response speed is low, interference and false triggering are likely to happen, a dual over-current protection mechanism combining desaturation voltage detection and sub-current detection is adopted. And by mixing and integrating the silicon substrate and the silicon carbide power device, the performance requirements of different application scenes are considered. Three driving control chips, six IGBT chips, six fast recovery diode chips, one SiC MOSFET chip, two silicon carbide Schottky barrier diode chips and one patch sampling resistor are integrated in the module, and all the elements are packaged in the same insulation heat dissipation substrate and lead frame combined structure, so that high integration level, high reliability and fast overcurrent protection are realized; the method can be widely applied to the fields of household appliances, industrial control, new energy and the like.

The application provides a multi-objective dynamic optimization method and system for a solar seawater desalination process, belonging to the technical field of solar seawater desalination control. Firstly, the application collects solution conductivity data at the inlet and outlet positions and irradiance trend data above the photovoltaic array. Then, the conductivity difference is calculated to generate gradient data to map the desalination demand vector, and the cloud motion vector is extracted from the irradiance data using the optical flow method to construct the energy supply potential vector. Subsequently, the two are aligned and convolved to generate a state space matrix, which is input into the constructed Kalman filter to predict the target voltage reference trajectory. Finally, the trajectory is substituted into the multi-objective constraint function to calculate the target duty cycle command, and the DC converter switching state is adjusted to change the operating voltage of the desalination device. The application can achieve real-time multi-objective dynamic optimization of the water production efficiency and equipment safety of the solar seawater desalination system under the dual fluctuations of light and salinity.

The application discloses a kind of game-based motivation-based adolescent psychological intervention digital systems, comprising: data acquisition module, obtain continuous audio stream data;Voice pre-processing module, continuous audio stream data is pre-processed, acoustic feature is extracted and generates emotional label, and continuous audio stream data is converted into text sequence data;Semantic analysis module is used for the semantic analysis of text sequence data, and logical syntax entity in text sequence data is extracted in conjunction with emotional label, and generates cognitive feature vector;Cognitive identification module, cognitive feature vector is input into model and is calculated, and the output cognitive distortion type and severity level;Intervention decision module is used for according to cognitive distortion type and severity level, and after the current execution node of game plot, insert hidden branch task;Dialogue generation module is used for driving virtual accompanying NPC to execute hidden branch task, and generates guiding speech, and dialogue generation module outputs guiding speech to user.

The invention discloses a low-power high-stopband suppression narrow-band filter, which comprises a packaging body, an outer side electrode and a plurality of circuit layers arranged in the packaging body, and is characterized in that the outer side electrode comprises an input end P1, an output end P2, a first grounding end P3 and a second grounding end P4; wherein the input end P1 and the output end P2 are symmetrically arranged, and the first grounding end P3 and the second grounding end P4 are symmetrically arranged; the input end P1, the output end P2, the first grounding end P3 and the second grounding end P4 are electrically connected with a transmission line in the packaging body; a first circuit layer is arranged at the bottom of the packaging body, the first circuit layer comprises two transmission lines and a first capacitor element, the two transmission lines are electrically connected with the input end P1 and the output end P2 respectively, and the two ends of the first capacitor element are electrically connected with the first grounding end P3 and the second grounding end P4 respectively. According to the technical scheme, the problem that an existing filter cannot achieve high-stop-band suppression under the condition of low-power operation is solved, and meanwhile multi-band and multi-mode communication can be achieved.

The invention provides a quantity monitoring method, device and equipment and a readable storage medium. The method comprises the following steps: acquiring channel state information of a space to be measured; performing data processing on the channel state information to obtain first amplitude data of the channel state information; taking the first amplitude data as the input of a target calculation model, and obtaining a monitoring result used for indicating the number of target objects in the to-be-detected space; according to the scheme, the channel state information of the to-be-detected space is obtained, and the features of the target objects can be extracted, so that the number of the target objects passing through the to-be-detected space is determined; by processing the channel state information, the interference of multipath components can be filtered while the characteristics of the channel state information are reserved, so that the calculation pressure of performing calculation according to a target calculation model is reduced. The problems that in the prior art, under the scene that the crossing object density is large and the target objects in the image are seriously overlapped, the image segmentation difficulty is high, and the estimation precision of the number of the target objects is poor are solved.

The invention discloses an intelligent adjusting device and method for an apron board of a conveyor, the device comprises a mounting bracket, a guide chute, an apron board assembly and a driving assembly, a plurality of flexible connecting pieces are additionally arranged, the flexible connecting pieces are connected between the driving assembly and the apron board assembly, and pressure sensors are packaged in the flexible connecting pieces. The elastic body of the flexible connecting piece is used for transmitting the adjusting driving force output by the driving assembly and can deform based on the counter-acting force of the belt, so that the apron board assembly can carry out passive self-adaptive following on the dynamic deformation of the belt, and meanwhile, a high-fidelity pressure signal for filtering vibration interference is provided for the sensor. Through the unique flexible sensing and force transmission integrated design, the problems that in the prior art, a sensor signal is prone to being interfered, the service life is short, and the apron board cannot be dynamically self-adapted are solved, and stable, accurate and self-adaptive adjustment of the sealing pressing force of the apron board is achieved.

The invention relates to a short-circuit fault protection system for a low-voltage direct-current system based on improved double-ring wavelet decomposition. The short-circuit fault protection system comprises a short-circuit fault early-stage detection module and a central control module, when a short-circuit fault occurs in the system, the short-circuit fault early-stage detection module detects a short circuit and sends hierarchical branches with detected faults and short-circuit fault current and voltage characteristics to the central control module through CAN bus communication, and the central control module determines the short-circuit fault early-stage detection module at a protection breaking position and issues a breaking instruction. And the short-circuit fault early-stage detection module issues a protection opening signal to the corresponding circuit breaker through the RS485 to complete selective breaking of the short-circuit fault. According to the invention, rapid detection and selective breaking after a short-circuit fault are realized.

The invention discloses a high-voltage ultralow-ripple DC-DC power supply which comprises a Royer resonance circuit, a voltage doubling rectifying circuit, a voltage feedback control circuit and a filter circuit. The Royer resonance circuit comprises a transformer U1, a coil L1, a capacitor C2, a triode Q1 and a triode Q2; a secondary side T6 of the transformer U1 and a secondary side T10 of the transformer U1 are both connected with a first end of the voltage doubling rectifying circuit; the second end of the voltage doubling rectifying circuit is connected with the filter circuit; the third end of the voltage doubling rectifying circuit is connected with one end of the voltage feedback control circuit; and the other end of the voltage feedback control circuit is connected between the emitter of the triode Q1 and the emitter of the triode Q2. The problems that in the prior art, a power supply cannot meet the requirement for high-voltage ultra-low ripples, and a driving circuit of an existing power supply is complex and high in cost are solved. The technical effects that the power supply has no switching noise and the driving circuit is simpler are achieved.

The present application relates to the technical field of medical film, and particularly relates to a medical film quality detection system based on multi-parameter fusion, which comprises an acquisition module, a discrete determination module, an identification module, a risk determination module, an adjustment module and an early warning module. The present application takes a dynamic discrete coefficient as a trigger condition, analyzes the contribution of each process parameter to the current thickness fluctuation to identify the primary root cause, forms a quantitative process risk index by comprehensively considering the out-of-control degree of the root cause parameter and the thickness deviation, and according to the process risk index, an adjustment instruction with clear direction and strength suggestion can be sent, and the adjustment efficiency is evaluated after adjustment, early warning is given when the control loop fails or the problem escalates, and the problems of lagging quality defect discovery and blind and lagging process adjustment caused by the failure to quickly and accurately locate the process abnormal root cause in the complex multi-process coupling production process are effectively solved.

The utility model discloses to solve the problem that the low frequency current transformer circuit in the prior art can complete the collection and conversion of current signal, however, restricted by the low frequency current transformer leakage magnetic effect, its measurement result often exists deviation, is difficult to satisfy the high standard requirement of precision control and data acquisition, provide a kind of low frequency current transformer circuit and electric energy meter based on integrated circuit hardware module control.The circuit includes current transformer CT, and the primary side winding of current transformer CT is connected with external measured circuit;Transimpedance amplifier, and the secondary side winding of current transformer CT is connected with transimpedance amplifier;Among them, the current size that current transformer CT collects is directly proportional to voltage size;Analog-digital converter, and analog-digital converter is connected with transimpedance amplifier;Analog-digital converter converts the analog quantity of voltage value into digital quantity;Integrated circuit hardware module, and integrated circuit hardware module is connected with analog-digital converter;Integrated circuit hardware module exports the final current value of high precision.

The utility model discloses a digital display terminal, which belongs to the technical field of high-power inverter power supplies and comprises a power supply and signal input end, a signal processing end, a chip processing end, a reference voltage end, a signal output end, a decimal point control end and a program burning end. The signal processing end, the decimal point control end, the chip processing end, the reference voltage end and the program burning end are all connected with the power supply and signal input end, and the signal processing end, the decimal point control end, the reference voltage end, the program burning end and the signal output end are all connected with the chip processing end. The utility model is widely applied to various welding devices, the output display is finer, and the readability of data is improved. The digital display terminal solves the problems of low resolution, high cost and high risk in the prior art.

A window anti-pinch control method, device and vehicle, the method comprising: obtaining a first signal collected by a first sensor and a second signal collected by a second sensor in real time during the operation of the window; obtaining a first window motor speed according to the first signal, and obtaining a second window motor speed according to the second signal; calculating the speed difference between the first window motor speed and the second window motor speed, and controlling the vehicle to trigger anti-pinch control according to the speed difference. The window anti-pinch control method, device and vehicle of the present invention perform anti-pinch control according to the speed difference between the window motor speeds obtained based on the first sensor and the second sensor based on the physical characteristics of the impact force during the operation of the window, and can optimize the anti-pinch control effect, while also filtering out interference from external working conditions.

The application discloses an AMT economic coasting control method and system, and relates to the technical field of vehicle transmission control, which comprises the following steps: obtaining vehicle operating state parameters to determine coasting entry conditions, and outputting an economic coasting condition satisfaction symbol when all the conditions are satisfied; obtaining the operating state of a mechanical automatic transmission, determining whether the state maintenance calibration condition is satisfied, and executing delay control, and activating the economic coasting state when the target delay time is reached; executing the neutral coasting process according to the operating state of the transmission, completing the decoupling of the transmission system, and entering the economic coasting; monitoring the exit trigger condition in the coasting period, and canceling the state when the condition is satisfied, calculating the target combination gear position, and restoring the on-gear operating state. The application prevents high-frequency switching of the system through multi-dimensional determination and delay mechanism, applies time alignment and speed regulation to reduce mechanical resistance during decoupling, and calculates the combination gear position based on the reference vehicle speed and synchronizes the speed during exit, so that the longitudinal impact of the vehicle during the recombination of the clutch is reduced.

The invention belongs to the technical field of tea leaf picking, and discloses an automatic tea leaf picking device which comprises a rack, a walking mechanism, a recognition mechanism, a picking mechanism, a collecting mechanism and a control mechanism. The picking mechanism comprises a mounting base, an adjusting block, an adjusting assembly, a guide driving assembly, an annular knife belt and picking teeth, an upper sliding groove and a lower sliding groove are formed in the adjusting block, the annular knife belt penetrates through the upper sliding groove, the guide driving assembly and the lower sliding groove, and the guide driving assembly on the other side forms a closed ring; the picking teeth on the annular cutter belts in the upper sliding groove and the lower sliding groove move reversely to form shearing cooperation to shear the fresh tea leaves; the collecting mechanism is used for collecting the cut fresh tea leaves; the control mechanism is used for controlling all the mechanisms to work. The annular cutter belt is adjusted through the adjusting assembly and the guide driving assembly to adapt to the shape of the tea canopy surface, so that the picking teeth can be precisely attached to the tea canopy surface, and the tea leaf picking quality is improved.

This invention discloses a power equipment inspection method based on deep learning dual-light feature fusion, comprising: simultaneously acquiring visible light images and infrared thermal imaging images of the power equipment using a binocular acquisition module mounted on an inspection robot; extracting significant straight line features from the two images using a gradient-based edge detection operator, and solving the homography matrix using line segment descriptors and geometric constraints to achieve online spatiotemporal registration without a calibration board; constructing a deep learning-based dual-stream feature extraction network to map the registered infrared image as a spatial attention mask, and performing weighted fusion of the visible light feature map using Hadamard product; finally, outputting equipment category, location, and temperature information based on the fused feature map, and determining faults using a dual threshold of confidence and temperature. This invention effectively solves the problems of texture loss in traditional infrared detection and the failure of visible light nighttime detection, achieving accurate location and diagnosis of power equipment faults.

The present disclosure provides a broadband receiver and a frequency calibration method thereof. The broadband receiver includes: a down-conversion mixing module arranged in the down-conversion section of the broadband receiver; it includes: a first multi-phase filter block, which is arranged to convert a pair of differential signals from a low noise amplifier into four orthogonal radio frequency signals with phases increasing by 90 degrees in sequence and pass them to a mixer group; a second multi-phase filter block, which is arranged to convert a pair of differential signals from an oscillator into four orthogonal local oscillator signals with phases increasing by 90 degrees in sequence and pass them to a mixer group; a mixer group, which is arranged to mix four orthogonal radio frequency signals with four orthogonal local oscillator signals to generate an intermediate frequency signal and pass it to the intermediate frequency part of the receiver. The present disclosure also provides a corresponding frequency calibration method. The broadband receiver provided in some embodiments of the present disclosure can reduce power consumption while maintaining a high image rejection ratio after switching the operating frequency.

The invention relates to the technical field of semiconductor measurement, in particular to a 3D NAND measurement system and method, in an existing CD-SAXS measurement light path, a phase grating used for enhancing a scattering signal of a memory hole structure and a phase grating used for enhancing a scattering signal of a deep groove structure are designed on the basis of a Talbot effect or a fractional Talbot effect, and according to the measurement requirement, the phase grating used for enhancing the scattering signal of the memory hole structure and the phase grating used for enhancing the scattering signal of the deep groove structure are designed. A switching device is used for controlling and switching gratings in a measuring light path, detection light is modulated through a phase grating, the light intensity distribution of the detection light irradiated to a sample is in a light and dark stripe shape related to the grating structure period and duty ratio, then the bright stripes are aligned with an area needing to be detected according to an alignment mechanism, and the detection light intensity is adjusted. Dark fringes are aligned with areas needing to be filtered, so that separation and extraction of scattering signals of a memory hole structure and scattering signals of a deep groove structure are enhanced, and mutual interference of the two scattering signals is avoided.

The present invention relates to a grid-connected monitoring device, including a shell, a power board, a core board and a bottom plate; the shell adopts a cylindrical structure with a rectangular cross section, a plurality of PCB guide grooves are arranged inside the shell, and the front and rear panels adopt an aluminum plate; the power board, the core board and the bottom plate are respectively installed inside the shell through the PCB guide grooves; the power board is electrically connected to the core board and the bottom plate respectively, and the core board and the bottom plate are electrically connected. The shell has good heat dissipation, strong anti-interference ability, good anti-seismic characteristics, can be fixedly installed, and can be installed on a guide rail, providing structural convenience for subsequent expansion modules; the core board integrates a CPU, Nand Flash, Nor Flash, SRAM and Ethernet physical layer chip, adds an independent filtering energy storage capacitor to ensure its stability; adds filtering and decoupling to filter out low-frequency and high-frequency interference or clutter.

This invention relates to the fields of geotechnical engineering and intelligent construction technology, specifically to a large-section trenchless tunnel settlement control and optimization system based on interlocking pipe curtain support. The system includes a central processing unit and connected modules for fluid characteristic sensing, transient impedance inversion, working condition judgment, and dual-mode adaptive control. The fluid sensing module periodically executes pulse excitation and collects fluid dynamic responses. The transient impedance inversion module calculates the equivalent sealing stiffness index characterizing the interlocking seal based on a leakage model. The working condition judgment module marks the grouting area as loose or dense by comparing it with a safety threshold. The dual-mode adaptive control module generates instructions accordingly, driving the grouting mechanism to perform pulsed intermittent or quasi-continuous stepped pressurization injection operations. This invention achieves effective control of surface settlement while ensuring that the underground concealed structure is not damaged.

The present application relates to the technical field of handwriting data recognition, and a student emotion evaluation model construction method and system based on multi-source handwriting features, comprising: handwriting feature data extraction on a character handwriting region to obtain current character writing data, wherein the current character writing data comprises a writing habit feature vector, a writing dynamic feature vector and a writing interval feature vector; handwriting change recognition on the current character writing data to obtain writing change feature data; emotion labeling on the writing change feature data to obtain labeled change feature data; and construction of a student emotion evaluation model according to the labeled change feature data. The present application can improve the accuracy of student handwriting recognition and improve the intelligent degree of emotion judgment during student writing.

This invention discloses a method and device for detecting material level in a closed silo, relating to the field of industrial automation detection and control technology. It employs a photosensitive level gauge to continuously acquire the original optical feedback signal of the solid material pile within the silo, receiving the light source sensor signal as the original optical feedback signal, forming signal frames in chronological order, with each frame corresponding to the light intensity value at a sampling time. Dynamic baseline tracking is performed on the acquired multiple signal frames, updating the baseline in real time using the weighted moving average of historical signal frames, and extracting the current optical signal trend component. The baseline update rate is automatically adjusted according to the degree of signal fluctuation. A multi-frame fluctuation suppression algorithm determines the deviation between the current signal frame and the baseline, dynamically filtering out instantaneous spikes caused by dust adhesion based on the statistical characteristics of the deviation. This invention significantly improves the detection accuracy, anti-interference capability, and operational reliability of automatic feeding systems for solid materials in kilns, and is suitable for industrial sites with high dust levels, variable light paths, and long operating cycles.

The invention discloses an electric power metering signal filtering method and equipment, relates to the technical field of electric power metering, and solves the technical problems that the filtering effect of a traditional filtering method for filtering strong electromagnetic signal interference is not ideal and the filtering requirement of electric power metering is difficult to meet on the premise that fundamental waves and effective harmonic waves are reserved. The method comprises the following steps: acquiring a metering signal, and acquiring the power frequency of the metering signal through a frequency calculation model; performing orthogonal modulation on the metering signal according to the power frequency to obtain an amplitude and a phase of a fundamental wave of the metering signal; according to the power frequency, the amplitude and the phase, fitting to generate a fundamental wave of the metering signal; and on the basis of the fundamental wave, filtering the metering signal through a time domain filtering model to obtain the harmonic wave of the metering signal. According to the invention, the interference of strong electromagnetic signals can be effectively filtered on the premise of keeping fundamental waves and harmonic waves, and the healthy operation of a power grid and the accuracy of electric energy metering are ensured.

The invention relates to the technical field of tunnel detection, in particular to a tunnel lining disease sonar detection device carried by an underwater robot, which comprises a sonar detection system, a data processing and analyzing system and an underwater robot carrying and operating system. According to the invention, a tunnel does not need to be emptied, autonomous operation is realized through carrying the detection device by the underwater robot, high risks of manual detection and adverse effects on a tunnel structure are avoided, and the sonar detection system realizes all-directional coverage detection of a tunnel lining by virtue of a high-resolution probe and a three-dimensional scanning module; the self-adaptive signal adjusting module can dynamically adjust parameters according to the underwater environment and adapt to complex water quality and water flow conditions, the data processing system accurately recognizes cracks, spalling, void and other diseases through a deep learning algorithm and determines key information of the diseases, data are visually displayed and stored in real time, and the real-time performance of the system is improved. A stable carrying platform, intelligent navigation and a reliable energy communication system provide stable guarantee for detection.

The utility model discloses a pickup special for a seven-stringed plucked instrument, and belongs to the technical field of musical instruments. In order to realize interference-free sound amplification and avoid squeal, the sound pickup comprises a shell, a miniature capacitor pickup head is embedded in the shell, one side of the shell is provided with a through hole and a lead wire, the lead wire is used for penetrating through the miniature capacitor pickup head, and an end cover is arranged at the upper end of the shell and is used for completely sealing the shell. The inner wall of the housing 1 is provided with a conductive silver paint layer, and the conductive silver paint layer is connected with the ground wire end of the miniature capacitor pickup head 2 and is used for shielding electromagnetic interference.

The invention discloses a lightning pulse comprehensive protection device for a motor control driver. The lightning pulse comprehensive protection device comprises a first filter connector, a second filter connector, a third filter connector, a power supply filter circuit, an RS422 bus protection circuit and a lightning pulse shielding cable, the power supply circuit is connected with an external power supply sequentially through the power supply filter circuit, the first filter connector and the power supply cable; the communication circuit is connected with an external upper computer through the RS422 bus protection circuit, the second filter connector and the communication cable in sequence; the driving circuit is connected with an external motor through a third filtering connector and a driving cable in sequence; a three-stage filtering voltage-stabilizing protection circuit board is arranged in the filtering connector and comprises a surge voltage suppression circuit, a peak voltage suppression circuit and a voltage stabilizing circuit; the power supply filter circuit is used for filtering; and the RS422 bus protection circuit is used for stabilizing voltage and limiting current. The invention provides lightning pulse comprehensive protection measures for each functional circuit of the motor control driver so as to realize lightning pulse comprehensive protection of the motor control driver applied to the field of flight products.

The embodiment of the invention relates to the field of optical fiber sensing, and discloses an optical fiber oil leakage detection method and device, a medium and a product. The method comprises the following steps: arranging a sensing optical fiber along a to-be-measured oil pipe, transmitting an optical signal to the sensing optical fiber and receiving a reflected signal of the sensing optical fiber; monitoring the change of the reflected signal in real time, and processing the reflected signal through a multi-modal feature fusion extraction method; the multi-modal feature fusion extraction method comprises time-frequency domain feature extraction, spatial domain feature extraction and multi-source data feature fusion; the time-frequency domain feature extraction comprises extraction of spectrum features and impact features of oil film diffusion; spatial domain feature extraction comprises the steps of constructing a concentration gradient field of oil film diffusion, and extracting spatial distribution features by using a neural network; the multi-source data feature fusion comprises the steps of synchronously collecting multi-source sensing data, and constructing a feature cross matrix to extract dimension reduction features; therefore, interference of steady-state mechanical noise caused by on-site pump valve starting and stopping, vehicle passing and the like is effectively filtered out, and precise qualitative detection of extremely weak oil leakage events is achieved.