797 results about "Digital signal processing" patented technology

A system and method for detecting anomalies in encrypted network traffic without decrypting encrypted payloads is disclosed. The invention comprises a hardware-accelerated pipeline including a packet acquisition unit configured to extract observable header attributes and timestamp values, a signal analysis unit implemented using digital signal processing circuitry to generate temporal and spectral characteristics of encrypted packet flows, and a morphometric extraction unit that produces encrypted-flow descriptors based on statistical dispersion, burst patterns, and ciphertext variability. A behavioral graph construction unit generates graph-structured representations of encrypted flows using incremental state-transition encoding. An artificial-intelligence inference unit employing a tensor-processing processor performs multi-stage anomaly analysis through temporal reconstruction, attention-based weighting of descriptors, and graph-structural deviation assessment to compute anomaly scores without decrypting any payload. A secure response control unit evaluates the scores against policy thresholds and performs mitigation actions while preserving confidentiality.

The present disclosure involves a medical device. The medical device includes an elongate cable assembly having a distal connector, a proximal connector, and a cable body coupling the proximal and distal connectors. The distal connector is configured for coupling with a diagnostic medical device. The proximal connector is configured for coupling with a medical measurement system. An electronic component is located inside the distal connector or the associated cable housing. The electronic component includes an analog-to-digital converter (ADC) and a microprocessor. The ADC is configured to receive medical data gathered by the diagnostic medical device and convert the medical data into digital signals. The microprocessor is coupled to an output of the ADC and configured to process the digital signals into a format that is readable by the medical measurement system.

The invention belongs to the technical field of underwater acoustic engineering and digital signal processing, and particularly relates to a fractional delay FIR (Finite Impulse Response) phase calibration method and system of a multichannel sonar system. Comprising the steps of signal acquisition and reference channel selection; high-precision relative delay estimation; calculating a cross-correlation function of other channel signals and the reference channel signal, performing coarse estimation by searching a peak point of the amplitude of the cross-correlation function, and performing fine estimation on the peak position by using a parabola interpolation method to obtain the delay time of each channel relative to the reference channel; designing an FIR fractional delay filter; digital filtering and phase calibration; verifying a calibration effect; and calculating the phase of each channel signal at the target frequency point after calibration, and counting the standard deviation of each channel signal so as to evaluate the improvement degree of phase consistency. The method aims at overcoming the defect that traditional integral multiple sampling delay correction precision is insufficient, high-precision phase compensation of a sub-sampling point level is achieved, and therefore the performance of algorithms such as beam forming of a multi-channel sonar system is remarkably improved.

A system for material detection and identification includes an interface configured to access a material database associating each of a plurality of materials with a resonance frequency and one or more transmission parameters; an RF transmitter configured to, for each material of at least a subset of the plurality of materials in the material database transmit into an environment an RF signal the resonance frequency for the material using the one or more transmission parameters; an RF receiver configured to receive a response signal from the environment; and a processor configured to analyze the response signal for resonance characteristics that indicate a presence of the material and identify the material to a user if the presence of the material is indicated by the resonance characteristics.

The invention discloses an electric energy meter abnormal phenomenon automatic detection and identification method and system, and relates to electric digital data processing, and the method comprises the steps: carrying out the digital signal processing of initial data, the voltage effective value, the total harmonic distortion rate and the analysis of communication message abnormal codes, and generating a structured feature matrix; on the basis of the structured feature matrix, threshold comparison, composite condition judgment and continuous anomaly detection are executed through multi-level rule triggering, and an anomaly event report is generated; comparing the abnormal event report with a historical case, obtaining the similarity between the current abnormal event report and the historical case, and obtaining a similarity TOP-N case set; generating an anomaly diagnosis report by using weighted evidence fusion in combination with rule triggering intensity quantification and case matching credibility conversion; and updating the case library according to the abnormality diagnosis report, and counting and adjusting a rule threshold based on a sliding window. According to the method, the abnormal judgment threshold values of key parameters such as voltage and harmonic waves can be adjusted in real time through dynamic threshold value optimization, and the adaptability is improved.

The invention relates to a detection-interference integrated unmanned aerial vehicle electromagnetic interference device, which belongs to the technical field of electronic countermeasure, and comprises an integrated design of an antenna module, a radio frequency front end module, a digital signal processing module and a main control module, the radio frequency front-end module comprises a detection receiving channel and an interference transmitting channel to process signal conversion, the digital signal processing module executes signal detection and analysis, intelligent interference decision and anti-self-interference signal processing based on a self-adaptive filtering algorithm, and the main control module is responsible for overall control and power supply. According to the invention, the technical problems of large response delay, complex system cooperation and incapability of continuous reconnaissance in the interference process of traditional anti-unmanned aerial vehicle equipment are solved. Real-time signal cancellation is achieved through the normalized least mean square algorithm, the reconnaissance capability is kept while interference is applied, the method has the advantages of being rapid in response, accurate in interference, low in power consumption and the like, and the countering efficiency is remarkably improved.

The invention discloses a distribution network power line anti-interference communication method based on adaptive filtering, and belongs to the technical field of distribution network power line communication. According to the method, a communication signal adopting a frequency shift keying modulation mode is acquired from a power line coupler of a distribution network through a signal acquisition module, the communication signal is preprocessed by using a digital signal processing unit, spectral analysis is performed on the preprocessed signal, and characteristic parameters of interference noise are extracted; a coefficient vector of a finite impulse response adaptive filter is initialized based on the characteristic parameters, the order of the filter is in direct proportion to the reciprocal of the dominant interference frequency, fine adjustment is carried out based on noise energy distribution through a table look-up method or a linear mapping relation, and the weight coefficient of the filter is adjusted in real time in the communication process. The adjustment step length is dynamically adjusted according to the real-time estimated signal-to-noise ratio, and finally, the processed signal is output through the adaptive filter and data demodulation is carried out. The method is mainly used for improving the anti-interference capability and the communication reliability of the power private line communication of the distribution network.

The invention provides a portable micro-beam X-ray fluorescence rapid detection method and system based on digital signal processing. The method comprises the following steps: firstly, constructing a micro-beam excitation parameter adaptive to a field environment, secondly, driving a micro-beam X-ray to irradiate a to-be-detected sample by using the micro-beam excitation parameter, synchronously obtaining an original fluorescence signal disturbed by the environment, then taking a dynamic adjustment amount as a calibration reference, and fusing the calibration reference and the original fluorescence signal to generate a combined data stream; then carrying out cooperative processing on the combined data stream through a digital signal processing technology, separating an environment disturbance component from a target fluorescence component, and finally generating a sample surface element distribution map based on the target fluorescence component. According to the technical scheme provided by the invention, the problems of morphology misalignment and dynamic noise interference caused by passive noise reduction design are solved, and the element detection reliability of complex morphology samples (such as soil blocks and cultural relic sections) is also improved.

The invention discloses a motor position non-contact sensing system and a signal processing control method. The system comprises a three-dimensional magnet assembly, a magnetic signal acquisition module, a digital signal processing unit, a voltage conversion unit and a cooperative control module. The three-dimensional magnet assembly and the acquisition module are coaxially arranged, magnetic points are in spatial gradient layout, the acquisition module comprises a three-dimensional magnetic field detection unit, a real-time phase calibration unit is arranged in the processing unit, and the cooperative control module adjusts sampling parameters based on the rotating speed. The method comprises the steps of initialization, magnetic signal acquisition, operation processing and voltage conversion output. According to the scheme, the problem of magnetic field signal distortion of an existing system is solved, stable and accurate sensing of the motor position is achieved, and the multi-scene motor control requirement is met.

A zonal audio system for a vehicle may include a microcontroller unit (MCU), a non-volatile storage communicatively coupled with the MCU that stores audio files for different types of audio functions, and a digital signal processing (DSP) module communicatively coupled with the MCU. The DSP module may process multiple types of audio functions simultaneously through a layered architecture that consolidates and prioritizes different audio streams including emergency calls, acoustic vehicle alerts, chimes, and infotainment.

The invention provides a programmable frequency control array radar waveform generation system and method based on an FPGA, and belongs to the technical field of radar systems and digital signal processing. In order to solve the technical problems of complex hardware system, inflexible parameter adjustment and poor multi-channel synchronism of the traditional frequency control array radar, the invention provides an integrated high-performance solution. The system adopts an FPGA (Field Programmable Gate Array) architecture of an integrated processing system (PS) and programmable logic (PL). The method comprises the following steps: a PS end receives waveform control parameters of an upper computer through a communication interface and transmits the waveform control parameters to a PL end; and a plurality of parallel direct digital frequency synthesizer (DDS) modules in the PL end synchronously generate multi-channel digital baseband signals with programmable frequency offset at high precision according to the parameters under the unified driving of the FPGA global clock network. And the digital signal is subjected to digital-to-analog conversion and radio frequency front-end processing to finally form a transmitting wave beam. According to the invention, flexible programmability of parameters is realized by utilizing a PS-PL collaborative architecture, the synchronization precision of multi-channel signals is remarkably improved through a global clock network and a parallel DDS module generated in the FPGA, and meanwhile, the system has the advantages of high integration level and low complexity.

The invention relates to the technical field of satellite navigation and wireless communication, and discloses an indoor positioning method and system based on feeder multiplexing Beidou double-frequency, and the method comprises the steps: receiving outdoor B1I and B2a signals through a high-gain Beidou double-frequency receiving antenna, carrying out the frequency separation and signal conditioning through a double-frequency separation filter, and carrying out the positioning of the B1I and B2a signals; and transmitting the B1I signal to an indoor distributed antenna for broadcasting through the existing communication feeder network, and transmitting the B2a signal to a central directional antenna to establish a time synchronization reference. A mobile terminal receives a dual-frequency signal, capturing and tracking are carried out through digital signal processing, and pseudo-range and carrier phase observation values are extracted. And performing pairing processing on observation data of the same antenna, calculating a dual-frequency pseudo-range difference value, eliminating system errors, and performing position calculation by adopting a weighted least square method and Kalman filtering. The method solves the problem that the traditional GPS signal cannot cover the indoor environment, and has a good application prospect in the scenes of underground commercial complexes, tunnels, parking lots and the like.

The invention discloses a relay device and method for long-distance few-mode optical fiber communication, and belongs to the field of optical communication. According to the device, firstly, optical signals transmitted in a few-mode optical fiber are separated into a plurality of independent mode channels through a mode decomposition multiplexer; then, an adjustable light delay unit is configured in each channel, and compensation is carried out according to a difference mode group delay difference pre-calculated or actually measured by a few-mode optical fiber parameter; furthermore, a dimmable amplifier is used for amplifying the signal, power monitoring is carried out at the output end of the amplifier through an optical fiber beam splitter and a photoelectric detector, closed-loop feedback control is formed, and gain of each channel is adjusted in a self-adaptive mode to eliminate mode-dependent loss. According to the invention, signal distortion can be effectively suppressed in an optical domain, the complexity of digital signal processing of a receiving end is reduced, and the transmission distance and the transmission capacity of a few-mode optical fiber mode division multiplexing communication system are remarkably improved.

Technology is disclosed for an optical receiver. The optical receiver may include an optical and digital signal processing (ODSP) device. The ODSP device may include a photodiode operable to convert an optical signal to an electrical signal; a digital signal processor operable to generate a digital signal based on the electrical signal; a quantization component operable to generate a quantized output signal based on the digital signal; and a processing device. The processing device may be operable to measure one or more signal statistics of the digital signal; and identify one or more quantization thresholds, wherein the one or more quantization thresholds are computed based on the one or more signal statistics.

The invention discloses a quantum double-ring cooperative current measurement device and method, and belongs to the technical field of electric measurement. The device comprises an outer ring unit used for measuring a high-frequency signal in current; the inner ring unit is used for measuring a low-frequency signal in the current; the digital signal processing unit is used for carrying out synchronous high-speed ADC sampling on the high-frequency signal measured by the outer ring unit and the low-frequency signal measured by the inner ring unit, carrying out fast Fourier transform on the sampled signal and converting the sampled signal into a frequency domain to obtain a VTMR (f) signal and a delta fNV (f) signal, and calculating the VTMR (f) signal and the delta fNV (f) signal to obtain the VTMR (f) signal and the delta fNV (f) signal. And reconstructing the full-band current waveform of the time domain. According to the invention, the measurement accuracy and reliability of the current sensor in broadband, high harmonic and strong interference scenes can be significantly improved, and the method is suitable for the fields of new energy grid connection, flexible direct current transmission, power grid protection, high-precision measurement and the like.

The invention relates to the field of digital signal processing, and provides a positioning method and device fusing direction of arrival estimation and terrain iterative correction, a medium and a product, and the method comprises the steps: estimating an arrival angle estimation value of a target radiation source signal; carrying out spatial geometrical relationship calculation by utilizing the estimated value of the angle of arrival to obtain a position coordinate expression of the target radiation source under a north-sky-east coordinate system; based on the digital elevation model and the target radiation source position coordinate expression, obtaining a target radiation source position initial value; and based on the initial value of the target radiation source position, completing iterative solution of the DEM data of the target area to obtain the target radiation source position. The method does not depend on platform movement and data accumulation, statically receives the target radiation source signal, performs high-precision estimation of the angle of arrival, combines DEM data of a target area, performs joint iteration to solve the position of the target radiation source, and realizes static, single-station, high-precision and rapid positioning of the target radiation source.

The application provides a wideband target array calibration system, device and calibration method thereof, which comprises a master control module, a digital signal processing module, a frequency conversion module and a four-element antenna; the four-element antenna is connected with the frequency conversion module through a microwave cable; the frequency conversion module is connected with the digital signal processing module through a microwave cable and a serial cable; the digital signal processing module is connected with the master control module through an optical fiber; and the master control module, the digital signal processing module, the frequency conversion module and the four-element antenna are connected to form the wideband target array calibration system. The application independently completes the calibration work at each working frequency point in the wideband and the calibration work in the instantaneous bandwidth, and does not depend on high-end instruments, so that the defect of long time consumption in the traditional calibration using the sweep frequency mode is overcome, and the calibration time is reduced.

The invention relates to the technical field of time length detection, and discloses a news simulcasting time length detection alarm method based on voice recognition, which comprises the following steps: S1, noise reduction: integrating an advanced digital signal processing technology and a professional noise reduction algorithm to form a refined processing system adaptive to'news simulcasting 'audio, according to the system, aiming at collected useless components such as environment noise and equipment noise, noise characteristics are captured through a multi-dimensional signal analysis model, an effective information core identifier is defined, a differentiated characteristic database of signals and noise is constructed, and a technician sets scientific noise reduction parameters according to the differentiated characteristic database. And accurate noise identification and stripping: integrating an advanced digital signal processing technology and a professional noise reduction algorithm, capturing noise characteristics through a multi-dimensional signal analysis model, accurately stripping environmental noise (such as studio echo and external interference sound) and equipment noise (such as sound recording equipment floor noise and transmission link electromagnetic interference), and simultaneously retaining the original texture of effective audio.

The invention relates to the technical field of power system monitoring, discloses an anti-harmonic PT current monitoring system and method, and aims to solve the problem of secondary side current signal distortion of a voltage transformer caused by power grid harmonic pollution in the prior art. The method comprises the steps of electrifying and initializing a system, starting a high-speed analog-to-digital converter to acquire a voltage signal, executing fast Fourier transform to identify dominant harmonic waves, calculating and configuring a capacitance value of a tunable LC trap unit to suppress specific harmonic waves, and finally outputting a high-fidelity analog voltage signal in direct proportion to fundamental current. The system comprises a current-voltage conversion module, a tunable LC notch filter array, a high-speed analog-to-digital converter, a digital signal processing unit and a microcontroller. According to the technical scheme, dynamic self-adaptive suppression and precise selective harmonic wave blocking of power grid harmonic waves can be realized, low delay and high fidelity characteristics are guaranteed, and the engineering practicability and reliability of the system are improved.

Digital signal processing (DSP) may be distributed across a plurality of endpoints and one or more aggregators in an audio system. An aggregator may perform DSP and / or may control DSP features performed by endpoints based on DSP feature capability of the endpoints and the aggregator. Links may be established between the aggregator and the endpoints to communicate audio signals and related information for performing the DSP features.

The invention discloses a dynamic reconfigurable signal processing platform based on a ZYNQ architecture, and belongs to the technical field of digital signal processing, and the dynamic reconfigurable signal processing platform comprises a channel preprocessing unit, a high-speed AD sampling unit, a ZYNQ-PL logic unit and a ZYNQ-PS algorithm processing unit. A radio frequency signal is fed in from an antenna end and then enters the channel preprocessing unit, a balun circuit and a filter bank are adopted to carry out preselection filtering, amplification and conditioning on the radio frequency signal, and the signal is extracted and sent to the high-speed AD sampling unit; the high-speed AD acquisition unit converts a received analog signal into a digital signal and transmits the digital signal to the ZYNQ-PL logic unit, and the ZYNQ-PL logic unit is connected with the ZYNQ-PS algorithm processing unit through an AXI bus; wherein the ZYNQ-PL logic unit is composed of a static region and three dynamic regions, and is mainly used for realizing a logic part of a functional waveform and completing reconstruction and loading of the functional waveform; and the ZYNQ-PS algorithm processing unit completes algorithm processing, realizes modulation and demodulation of a functional waveform and realizes a functional algorithm.

The invention belongs to the technical field of encoder signal processing, and particularly relates to an encoder capable of realizing non-contact rotation through a measurement magnetic ring of a magnetic induction technology and a TMR magnetic induction read head encoder, performing digital signal processing through a DSP under the driving of a high-speed motor, and integrating signal direct-current bias, amplitude phase difference correction and temperature detection through a program. High-precision position feedback is achieved by subdividing and encoding sine and cosine orthogonal signals inductively output by the measuring magnetic ring, the RS485 protocol communication has the advantages of being high in anti-interference capacity and rich in communication protocol, state monitoring information can be obtained while position information is obtained, motor parameters and encoder parameters can be stored in a built-in mode, and high-precision position feedback can be achieved through a driver. The upper computer is used for reading and modifying, operation is convenient, and the application range is wide.

The invention provides an electric power meter data real-time analysis and abnormity early warning method based on edge calculation, and belongs to the technical field of data analysis and early warning, and the method comprises the steps: collecting the multi-modal data of an electric power meter based on a multi-channel analog-to-digital converter, employing a hardware filter circuit to eliminate high-frequency noise, and obtaining the data of the electric power meter; signal gain self-adaptive adjustment is carried out based on a reconfigurable amplifier; a digital signal processing accelerator is used to carry out Fourier transform on a matrix constructed by the standardized data stream, and a multi-core processor is combined to carry out analysis to generate a feature vector; the method comprises the following steps: acquiring environmental parameters in real time based on an environmental sensor, dynamically adjusting an anomaly detection threshold in combination with a machine learning model trained by historical data, and comparing a feature vector with the dynamic threshold to generate an anomaly signal; the relay control circuit triggers sound-light alarm, the physically isolated communication module sends an early warning instruction to the cloud platform, and meanwhile, the redundant power supply module is started to control the electric power meter to operate continuously. And the efficiency and accuracy of subsequent abnormity early warning are improved.

A digital signal processing method is for enhancing fidelity of equivalent-time waveform measurements. The method includes receiving a digitized equivalent-time waveform of a repeating signal under test (SUT), applying a low-pass filter to the digitized equivalent-time waveform to obtain a smoothed waveform, generating a residual waveform by subtracting the smoothed waveform from the digitized equivalent-time waveform, estimating contributions of multiple noise sources in the residual waveform using a regression model, computing target noise and jitter values by removing known intrinsic contributions, and reconstructing a corrected waveform by combining the smoothed waveform with a scaled version of the residual waveform, wherein the scaling is based on the target noise source contributions.

The invention discloses a digital signal processing method and system based on an FPGA, relates to the field of digital signal processing, and introduces a staged variable bandwidth CDR strategy. In the initial stage, the signal frequency offset is quickly estimated through feedforward frequency analysis, and a high-bandwidth loop is started on the basis of the signal frequency offset, so that top-speed locking is realized, and the requirements of production testing and other scenes on efficiency are met. When the system confirms that locking is stable through hardware logic, a multi-step interpolation state machine is triggered, the state machine can smoothly switch the coefficient of the loop filter from a high bandwidth mode to a low bandwidth mode without disturbance, and the lock losing risk in the switching process is avoided. Finally, in a stable low-bandwidth mode, the system can perform accurate jitter decomposition and data analysis by using a high-precision recovery clock. In this way, the two modes of rapid capture and high-precision measurement are fused in one operation process, and the static design limitation in the prior art is solved.

The invention discloses a chip verification platform based on an FPGA (Field Programmable Gate Array) and a verification method thereof. The platform comprises an FPGA core configured to be used for realizing prototype logic of a chip to be verified and executing digital signal processing, an intermediate frequency input module, and a system clock configured to be used for guaranteeing time sequence synchronization of all modules of the platform, the external interface is configured to support communication verification between the chip to be verified and external equipment; the debugging interface is configured to realize signal monitoring and problem positioning in a verification process; the intermediate frequency input module is configured to receive an analog intermediate frequency signal output by a radio frequency front end and provide a compliant intermediate frequency signal source for verification; the intermediate frequency input module comprises a Balun unit, an ADC unit and a CPLD data distribution module which are connected in sequence. And the CPLD data distribution module completes adaptation and distribution of digital intermediate frequency signals by dynamically switching data transmission paths and controlling multi-channel data priorities. And the chip verification efficiency and reliability are improved.

The invention provides a self-adaptive control method for quality fluctuation in a wire extrusion process. The self-adaptive control method comprises the following steps: acquiring the thickness of an insulating layer, the thickness of a sheath layer, the outer diameter size and surface quality data at an outlet of an extruder, and performing digital signal processing to obtain a standardized thickness uniformity index; performing classification judgment according to the standardized thickness uniformity index, and if the standardized thickness uniformity index deviates from a preset threshold value, marking the standardized thickness uniformity index as a quality fluctuation event; determining a fluctuation type according to the quality fluctuation event; according to the optimized temperature set value, parameters of an extruder control system are updated, and the operation state is fed back; determining the adjustment effectiveness according to the comparison between the operation state and an initial standardized thickness uniformity index; after the adjustment is confirmed to be effective, collecting the batch diameter of the raw material and environment temperature and humidity data and fusing to obtain a comprehensive environment influence factor; and judging whether the traction speed needs to be subjected to secondary adjustment or not according to the comprehensive environmental influence factor, obtaining a final stable extrusion process parameter group, and transmitting the final stable extrusion process parameter group back to a control system.

The invention discloses a storage and calculation integrated array convolution acceleration device and method based on sparse coding, and belongs to the field of artificial intelligence chip design and digital signal processing. The device comprises an unpacking module, a packing module, a calculation reasoning module, a weight configuration module and a state control module. The unpacking module checks and decodes the received data packet, and distributes control information and data content to the weight configuration module or the calculation reasoning module; in a weight configuration mode, the weight configuration module converts an unpacking result into a parallel format, and controls the storage and calculation integrated array to be written into a sparse convolution kernel; in a reasoning mode, the calculation reasoning module decodes sparse excitation and drives the photoelectric storage and calculation integrated unit array to perform convolution calculation, and outputs a calculation result to the packaging module; and the packaging module packages the calculation result and the checksum packet header information and outputs the packaged calculation result and checksum packet header information to the outside. Through combination of a modular architecture and a sparse coding mode, the calculation efficiency is improved, and the input data volume is reduced at the same time.

The invention discloses an ion sensor state prediction and correction method and system based on mechanism modeling, and relates to the technical field of sensor state monitoring and predictive maintenance, and the correction method comprises the steps: obtaining the original information of an ion sensor in a historical time period; then signal preprocessing is carried out, parameter estimation is carried out based on an extended Nernst model and a state estimation algorithm, and parameter evaluation indexes are obtained; calculating the health index and the remaining service life of the ion sensor; making a correction strategy; according to the method and the system provided by the invention, intelligent health management, accurate life prediction and dynamic performance correction of the ion sensor are realized on the basis of the extended Nernst model and state estimation by utilizing a machine learning algorithm, digital signal processing and adaptive control, and important technical support is provided for wide application of the ion sensor.

The invention discloses a DSP (Digital Signal Processor) online self-adaptive wavelet denoising and concentration inversion system and method for TDLAS (Tunable Diode Laser Absorption Spectroscopy) measurement, and relates to the technical field of gas spectrum detection. Comprises: a laser module for emitting semiconductor laser light; the absorption cell module is used for absorbing specific components of the laser through a gas absorption cell formed by the to-be-detected gas; the detection and amplification module is used for converting the transmission light signal into an electric signal and amplifying the electric signal through a photoelectric amplifier; the phase-locked amplification module is used for filtering and extracting noise; the digital signal processing module is used for performing digital sampling, performing wavelet denoising and signal reconstruction, performing wavelet inverse transformation reconstruction on a denoised waveform, and extracting a second harmonic characteristic parameter; and the upper computer module is used for obtaining the concentration of the gas to be detected based on a pre-established gas concentration inversion model according to the second harmonic characteristic parameters. The method is suitable for high-precision detection of trace gas, and has the obvious advantages of strong real-time performance, high precision, good system stability, good portability and the like.