CN119043719A - Rotary machine fault diagnosis system used under variable rotation speed working condition - Google Patents

Abstract

The invention relates to a rotary machinery fault diagnosis system used under a variable rotation speed working condition, which comprises seven parts, namely a vibration sensor, a rotation speed measuring sensor, a band-pass filter, an envelope detection demodulator, a signal collector, a control and signal processor and a rotation speed detection circuit, the vibration signal collected by the vibration sensor is used for extracting an envelope signal through a band-pass filter and an envelope detection demodulation module, meanwhile, a frequency synthesis module is used for obtaining sampling frequency pulses changing along with the rotating speed and controlling a signal sampler to collect signals, then an angular domain signal processing module is used for carrying out low-pass filtering on the angular domain signals, and finally feature extraction and fault diagnosis are carried out. The method has the advantages that the precision, the range and the instantaneity of the rotation speed tracking can be effectively improved, the calculated amount of an algorithm can be reduced by using the angle domain signal FIR filtering, the operation efficiency is improved, and meanwhile, the hardware cost of a system is reduced.

Description

Rotary machine fault diagnosis system used under variable rotation speed working condition

Technical Field

The invention relates to a feature extraction method and a feature extraction system for fault diagnosis of rotary machinery, in particular to a fault diagnosis system for rotary machinery under a variable-rotation-speed working condition.

Background

In industrial applications, the purpose of real-time monitoring of the state of a rotating machine is to evaluate the operating conditions of the machine in order to determine the maintenance location and the timing without the need to shut down and disassemble the machine, and at the same time to monitor the degree of wear on the machine, so that the machine is removed from service before failure, ensuring safe operation of the machine, avoiding catastrophic failure due to excessive wear, and reducing the operating costs for the management and maintenance of the machine. In actual conditions, the rolling bearing generally works under a variable rotation speed condition, so that nonlinearity and instability of a vibration signal of the rolling bearing are more complex than those of the rolling bearing under a constant rotation speed condition. Therefore, it is significant how to extract information from nonlinear and non-stationary vibration signals, which can effectively reflect the bearing state. The order analysis is one of the more common tools in fault diagnosis research under variable working conditions, and the core of the order analysis is accurate acquisition of equal-angle resampling time.

In the process of angular domain signals obtained through equal-angle resampling, two sampling links are time domain sampling of constant sampling frequency and time domain-to-angular domain resampling. In the two links, the time domain sampling can introduce strong background noise and time domain aliasing signals, and when the existing calculation order tracking is used for resampling, the problems of low rotation speed tracking precision, narrow tracking range and discontinuous rotation speed pulse counting exist in the operations of rotation speed estimation, angle time scale calculation, interpolation filtering and the like, which can lead to interference signals and irrelevant components in the resampled signals. And then, the processing process of eliminating the interference component exists in the learning link, which also has influence on fault feature extraction, and meanwhile, the fine diagnosis is difficult to realize.

Therefore, on the basis of the existing calculation order tracking, on the premise of reducing the hardware cost of the system, the accuracy, the range and the instantaneity of the rotation speed tracking are improved, and the interference component in the resampled signal is removed.

Disclosure of Invention

In order to overcome the technical problems, the invention discloses a rotary machine fault diagnosis system used under a variable rotation speed working condition.

The technical scheme of the invention is that the system for diagnosing the rotating machinery faults under the variable-speed working condition comprises seven parts, namely a vibration sensor, a rotating speed measuring sensor, a band-pass filter, an envelope detection demodulator, a signal acquisition device, a control and signal processor and a rotating speed detection circuit, wherein the vibration sensor acquires vibration, impact and temperature signals in real time and outputs the signals to the band-pass filter, the band-pass filter carries out band-pass filtering to extract resonance frequency band signals taking the natural frequency of the sensor as the center frequency, then the resonance frequency band signals are transmitted to the envelope detection demodulator, the envelope detection demodulator extracts envelope signals in the resonance frequency band, the signal acquisition device acquires envelope signals, and finally the envelope signals are transmitted to the control and signal processor for signal processing and fault feature extraction and identification, the rotating speed measuring sensor synchronously measures the rotating speed signals while carrying out vibration signal processing and acquisition, and the frequency synthesis module integrated in the control and signal processor calculates sampling frequency pulses in real time, so as to realize tracking of the sampling frequency pulses, complete acquisition of the degree signals and provide a data basis for fault feature extraction; the control and signal processor is used as the core of the method and system, the hardware circuit and the software algorithm are integrated in the control and signal processor, the hardware part is composed of an MCU and the peripheral circuit thereof, the algorithm is integrated in the MCU for controlling the frequency synthesis module to realize the generation of sampling pulse frequency, the processing of angular domain signals and the extraction of fault characteristics, when the rotary machinery fault diagnosis system works, the vibration signals collected by the vibration sensor pass through the bandpass filter and the envelope detection demodulation module designed by the system to obtain the envelope curve of the resonance frequency band caused by the rotary machinery fault, the rotating speed detection circuit obtains a rotating speed signal, the frequency synthesis module calculates sampling frequency pulses which change along with the rotating speed, the control signal collector is used for collecting envelope signals, the collected signals are transmitted to the angular domain signal processing module for time domain angular domain conversion and angular domain signal low-pass filtering of the signals, anti-aliasing filtering and high-order interference signal removal are achieved, finally, the filtered angular domain signals are subjected to FFT to obtain an order spectrum, and fault diagnosis of the rotating machinery is achieved by comparing the order spectrum with fault characteristic orders; the method and the system can effectively improve the precision, the range and the instantaneity of the rotation speed tracking, can reduce the calculated amount of an algorithm by using the angle domain signal FIR filtering, improve the operation efficiency and simultaneously reduce the hardware cost of the system.

The control and signal processor is internally integrated with a frequency synthesis module, an angular domain signal processing module and a characteristic extraction and identification module, wherein the frequency synthesis module receives a rotating speed pulse signal of a rotating speed detection circuit and realizes real-time tracking and counting of rotating speed according to a rotating speed signal counter integrated in the frequency synthesis module, the rotating speed pulse which is tracked in real time is converted into sampling frequency pulses by an algorithm integrated in the frequency synthesis module, the angular domain signal processing module comprises a time domain-angular domain conversion and an angular domain signal low-pass filter, the time domain-angular domain signal conversion is used for mapping the acquired time domain signal into the angular domain signal, the angular domain signal low-pass filter is used for carrying out anti-aliasing filtering on the angular domain signal and removing a high-order interference signal so as to avoid spectrum aliasing when the characteristic is extracted and interfere with the extraction of the fault characteristic, the characteristic extraction is used for extracting the fault characteristic after FFT on the filtered signal so as to provide reference opinion for maintenance and overhaul of rotating machinery equipment by a user, and the control and signal processor can accurately realize real-time and wide-range rotating speed tracking of the rotating machinery by the frequency synthesis module integrated in the frequency domain signal processing module and the angular domain signal processing module, the characteristic extraction is used for realizing the realization of real-time and wide-range of rotating machinery, and the frequency tracking efficiency of a system can be reduced, and the cost of a system can be removed.

The invention discloses a frequency synthesis module, which comprises an input part, an operation part and an output part, wherein the input part is used for inputting a system clock frequency f _sys, a rotating speed pulse f _ep transmitted by a rotating speed detection circuit and a frequency multiplication coefficient K, the frequency synthesis module is used for providing data, an operation coefficient and a reference frequency for operation, so that a system can accurately, real-time and continuously calculate a changed rotating speed, the operation part is internally provided with a pulse counter, an overflow counter, a calculator and a timer, the operation part is used for calculating different output frequencies according to different input parameters and outputting sampling frequency pulses for a time domain sampler, the module work flow comprises four steps, namely, a step 1 is used for reading and calculating parameters, the rotating speed frequency is calculated according to the frequency multiplication coefficient K and the sampling order O _s of monitoring equipment, a step 2 is used for calculating the rotating speed frequency according to the read rotating speed signal pulses and the parameters of the step 1, a step 3 is used for outputting sampling frequency pulse calculation according to the rotating speed frequency calculated in the step 2, and outputting the sampling frequency pulse according to the sampling frequency calculation, and the frequency synthesis module can improve the rotating speed tracking precision and the range and the continuity of the rotating speed pulse counting.

In the invention, the angular domain signal low-pass filtering is used for carrying out anti-aliasing filtering and removing interference signals on the acquired angular domain signals, and is divided into three steps, (1) the angular domain signals are read, (2) when the setting mode is judged, the sampling order O _clk and the cut-off order O _s of the parameters are calculated by the read filter, the FIR filter coefficient h _n is calculated according to the two parameters which are set, the parameter updating judgment is carried out when the setting mode is not the initial setting mode, the parameters are changed, the filter coefficient h _n is calculated again by the read filter calculation parameters, the filter coefficient h _n is read when the filter parameters are not changed, the next step is carried out, (3) convolution operation is carried out, and the calculation result is output, so that the anti-aliasing filtering and the interference signal removal of the angular domain signals can be realized.

The method and the system have the beneficial effects that the accuracy, the range and the instantaneity of the rotation speed tracking can be effectively improved, the FIR filtering of the angular domain signals is realized, and meanwhile, the hardware cost of the system is reduced.

Drawings

FIG. 1 is a block diagram of a rotary machine fault diagnosis system under variable speed conditions of the present invention;

FIG. 2 is a block diagram of a frequency synthesis module of the present invention;

FIG. 3 is a flow chart of the operation of the frequency synthesis module of the present invention;

FIG. 4 is a schematic diagram of a tachometer frequency counting process;

Fig. 5 is a flow chart of the low pass filtering of the angular domain signal of the present invention.

Detailed Description

The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is apparent that the described embodiments are only some embodiments of the present invention, not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.

Referring to fig. 1, a fault diagnosis system for rotary machinery under variable rotation speed working conditions comprises a vibration sensor, a rotation speed measuring sensor, a band-pass filter, an envelope detection demodulator, a signal collector, a control and signal processor and a rotation speed detection circuit, wherein the vibration sensor collects vibration, impact and temperature signals in real time and transmits the signals to the band-pass filter, the band-pass filter is realized by hardware, parameters of the band-pass filter are determined by natural frequency f _n of the vibration sensor, the band-pass filter is used for band-pass filtering to extract a resonance frequency band signal taking the natural frequency f _n as a central frequency, then the envelope detection demodulator is used for extracting an envelope signal in the resonance frequency band, the frequency of the envelope signal at the moment is related to the rotation speed of the rotary machinery, the signal collector is used for collecting envelope signals, and the abscissa of the collected signals at the moment is a time sequence, the time sequence is a non-stationary sequence, the sampling frequency is changed along with the rotation frequency of the monitoring equipment when the signal collector collects envelope signals, but the sampling frequency is unchanged relative to the rotation frequency, which causes the collected signals to be the non-stationary signals when the abscissa is the time sequence, the collected envelope signals are always stationary signals when the angle sequence (angle position) is the abscissa, the collected envelope signals are finally transmitted to the control and signal processor for signal processing and fault feature extraction and identification, the rotation speed measuring sensor synchronously measures rotation speed signals when the vibration signal processing and the collection are carried out, the rotation speed signals are detected through the rotation speed detecting circuit and transmitted to the frequency synthesis module integrated in the control and signal processor for calculating sampling frequency pulses in real time, so as to realize the tracking of the sampling frequency pulses, the collection of the equiangular signals is completed, the vibration sensor is a multi-parameter sensor and is arranged on a monitoring equipment shell and used for collecting vibration, impact and temperature signals of a rotary machine, the band-pass filter is realized in a hardware circuit mode, the center frequency of the band-pass filter is determined by the natural frequency f _n of the vibration sensor and is used for extracting resonance frequency band signals caused by faults, meanwhile, unnecessary high-frequency interference signals, environment noise and low-frequency vibration signals in the collected vibration signals are removed and data are provided for envelope detection and signal collection, the envelope detection demodulator is realized in a hardware circuit and is used for extracting fault envelope signals from the resonance frequency band and providing data for signal collection, signal processing and feature extraction, the signal collector is realized in a dynamic sampling mode, and the sampling pulse frequency is provided by a frequency synthesis module and is used for realizing angular collection of envelope signals and the like under variable rotation speed.

The control and signal processor is used as the core of the method and system, and comprises a hardware circuit and a software algorithm, and comprises a MCU and a peripheral circuit thereof, wherein the MCU is used as a core component, and the MCU is internally integrated with signal processing, feature extraction and fault diagnosis algorithms for controlling the frequency synthesis module to realize the generation of sampling pulse frequency and tracking filtering frequency, the processing of angle domain signals and the extraction of fault features. The control and signal processor is an integral body, a frequency synthesis module, an angular domain signal processing module and a feature extraction module are integrated in the integral body, fault diagnosis of the rotary machine under a variable speed working condition is completed by the frequency synthesis module, the frequency synthesis module is realized by adopting a software and hardware combination mode based on a timer in the MCU, the frequency synthesis module receives a rotating speed pulse signal of the rotating speed detection circuit in real time through an external interrupt function in the MCU, realizes real-time tracking and counting of the rotating speed according to a rotating speed signal counter integrated in the MCU, and an algorithm integrated in the integral body converts the rotating speed pulse tracked in real time into a sampling frequency pulse; the angular domain signal processing module comprises a time domain-angular domain conversion and an angular domain signal low-pass filter, wherein the time domain-angular domain conversion is used for mapping a non-stable time sequence in an acquired time domain signal into an angular domain signal x (theta) with stationarity at equal angular intervals, the angular domain signal low-pass filter is used for carrying out anti-aliasing filtering on the angular domain signal and removing a high-order interference signal so as to avoid frequency spectrum aliasing during feature extraction and fault diagnosis, the feature extraction is carried out, the filtered angular domain signal is firstly subjected to FFT conversion before feature extraction, the spectrum after the conversion is an order spectrum, then the protruding spectrum with 3 harmonic orders is extracted from the order spectrum and is compared with a theoretical fault feature order, the existence of a fault of the monitoring device can be determined when the non-stable time sequence is equal, the specific fault position can be further determined according to the fault order, the non-existence of the fault of the monitoring device can be initially determined when the non-stable time sequence is unequal, but the judgment basis can be provided for the fault states of other devices, the control and signal processor can realize real-time, accurate and large-scale rotation speed tracking of the rotary machine by integrating the frequency synthesis module, the angular domain signal processing module and the feature extraction and identification, can improve the system operation efficiency, and can reduce the system hardware cost by removing an additional frequency synthesizer circuit.

Referring to fig. 2, 3 and 4, a frequency synthesis module block diagram, a workflow diagram and a rotational speed frequency counting process schematic diagram are shown. The frequency synthesis module comprises an input part, an operation part and an output part, wherein the input part is used for accurately and continuously tracking the rotating machine rotating speed frequency and sampling frequency in real time, the input part comprises a system clock frequency f _sys, a rotating speed pulse f _ep transmitted by a rotating speed detection circuit and a frequency multiplication coefficient K, and is used for providing reference frequency, input data and operation coefficient for operation, so that the changing rotating speed frequency can be accurately and continuously calculated in real time, and the operation part is internally provided with a pulse counter, The overflow counter, calculator and timer, in which the pulse counter and overflow counter are respectively a 32-bit counter, and are used for calculating different output frequencies according to different input parameters, and outputting them, and transferring them into signal collector and angle domain signal processing module so as to make the signal collector obtain real-time sampling frequency pulse, and provide basis for obtaining accurate angle domain signal, and when N data are collected as a group for calculation, the working flow of frequency synthesis module is divided into four steps, and implemented, step 1, the system parameters are read, and according to the highest fault order actually existed in the monitoring equipment the frequency multiplication coefficient K is set, The sampling order O _s, according to the sampling theorem, O _s is more than 2 times of the maximum fault order to be analyzed, the maximum fault order in fault diagnosis is determined by the mechanical structural characteristics of the monitoring equipment, and meanwhile, signals below 3 times of the maximum fault order are required to be reserved when fault analysis is carried out, so that O _s is set according to 6 times of the maximum fault order to be analyzed of the monitoring equipment, namely O _s>6O_max, the system clock frequency f _sys is set according to a rotating speed conversion interval, the two parameters provide a calculation basis for the subsequent links, and in the step 2, the rotating speed frequency is calculated, and the rotating speed frequency is calculated according to the read rotating speed signal pulse and the system parameters set in the step 1 and is divided into a count, Calculating the rotating speed frequency, wherein (1) the pulse counter counts the number of counts N _ep,n (n=0, 1,2, N-1) within the duration of positive half periods (the pulses adopt square waves with the duty ratio of 50%) of 1 rotating speed pulse, and meanwhile, the overflow counter counts the number of overflows of the pulse counter N _eq,n, and then the number of the whole periods N _cp,n=2³²×N_eq+N_ep,n of one rotating speed pulse is calculated, and (2) the rotating speed frequency is calculated according to the calculation formula: Wherein f _ep,n is the nth rotational frequency, T _ep,n is the nth rotational pulse period, The PSC ₁ is a prescaled coefficient of the pulse counter for counting 1 pulse frequency of the pulse counter, and the step 3 is used for outputting sampling frequency pulse calculation for calculating the filter frequency and the sampling frequency according to the rotating speed frequency calculated in the step 2 and further calculating the output sampling frequency pulse according to the sampling frequency, and the specific implementation process comprises (1) according to the rotating speed frequency f _ep,n, calculating the frequency of the pulse according to the formulaCalculating the sampling pulse frequency f _s,n, wherein O _s is the sampling order, (2) calculating the timer reload value ARR _n,ARR_n for controlling the sampling pulse according to the sampling pulse frequency f _s,n, wherein the calculation formula isThe PSC ₂ is a pre-frequency-dividing coefficient of the timer, (3) the reloading value of the timer is converted into an output sampling frequency pulse, the timer outputs the sampling frequency pulse according to the newly set reloading value, and the frequency synthesis module can effectively improve the rotation speed tracking precision and range.

Referring to FIG. 5, a low-pass filtering flow chart of angular domain signals is shown, wherein the low-pass filtering is used for anti-aliasing filtering and removing interference signals on the collected angular domain signals, and the implementation flow is that (1) the angular domain signals are read, (2) a setting mode is judged, when the setting mode is initial setting, a filter calculation parameter O _s is read, a filter cut-off order O _clk is determined according to a sampling theorem, and then a FIR filter coefficient h _n,h_n is calculated according to the two set parameters, wherein the calculation formula is thatWhere x _W (M) (m=0, 1,2,., M-1) is a window function,If O _clk is normalized at 0-2pi, M is the length of a window function, if the length of the window function is not equal to the length of the window function, parameter updating judgment is carried out, if the filter setting parameters are changed, the calculation of a filter coefficient h _n is carried out again according to the updated filter setting parameters, if the filter parameters are not changed, the filter coefficient h _n is read, the next step is carried out, (3) convolution operation, the convolution operation is carried out on angle domain signals x (theta) and h _n, and filtered signals are output, so that a basis is provided for feature extraction, and anti-aliasing filtering and interference signal removal of the angle domain signals can be realized.

When the rotary machinery fault diagnosis system works, vibration signals acquired by the vibration sensor pass through a band-pass filter and an envelope detection demodulation module designed by the system to obtain an envelope curve of a resonance frequency band, meanwhile, a frequency synthesis module synthesizes sampling frequency pulses and tracking filtering frequencies which change along with the rotation speed through the rotation speed signals acquired by the rotation speed detection circuit, wherein the sampling frequency pulses control a time domain signal sampler to acquire time domain signals, the acquired signals are transmitted to a time domain signal processing module to perform time domain conversion and low-pass filtering of the signals, finally, the filtered time domain signals are subjected to FFT to obtain an order spectrum, and fault diagnosis of rotary machinery is realized by comparing the order spectrum with fault characteristic orders.

The method and the system have the advantages that the accuracy, the range and the instantaneity of the rotation speed tracking can be effectively improved, the calculated amount of an algorithm can be reduced by using the angle domain signal FIR filtering, the operation efficiency is improved, and meanwhile, the hardware cost of the system is reduced.

The foregoing description of the preferred embodiments of the invention is not intended to be limiting, but rather is intended to cover all modifications, equivalents, alternatives, and improvements that fall within the spirit and scope of the invention.

Claims (4)

1. The present invention is a rotating machinery fault diagnosis system for variable speed working conditions, comprising a vibration sensor, a speed measurement sensor, a bandpass filter, an envelope detection demodulator, a signal collector, a control and signal processor, and a speed detection circuit. The vibration sensor collects signals and transmits them to the bandpass filter. After bandpass filtering, the envelope detection demodulator extracts the envelope signal. At the same time, the speed measurement sensor measures the speed signal, which is transmitted to the frequency synthesis module integrated in the control and signal processor after passing through the speed detection circuit to provide a real-time changing sampling frequency pulse. The sampling frequency pulse controls the signal sampler to collect time domain signals, which are then transmitted to the control and signal processor for signal processing and fault feature extraction to achieve rotating machinery fault diagnosis. The control and signal processor is the core of the system, and is used to control the frequency synthesis module to realize the generation of sampling pulse frequency and tracking filter frequency, the generation of angular domain signals, and the generation of sampling frequency and tracking filter frequency. Processing, extraction and identification of fault characteristics; when the rotating machinery fault diagnosis system is working, the vibration signal collected by the vibration sensor passes through the bandpass filter and envelope detection demodulation module designed by the system to obtain the envelope signal of the resonance frequency band, and at the same time, the frequency synthesis module synthesizes the sampling frequency pulse and tracking filter frequency that change with the speed through the speed signal obtained by the speed detection circuit, wherein the sampling frequency pulse controls the time domain signal sampler to collect the time domain signal, and transmits the collected signal to the angular domain signal processing module for time domain and angular domain conversion of the signal and angular domain signal low-pass filtering, and finally performs FFT transformation on the filtered angular domain signal to obtain the order spectrum, and compares the order spectrum with the fault feature order to realize the fault diagnosis of the rotating machinery; the method and system can effectively improve the accuracy, range and real-time performance of speed tracking, and the use of angular domain signal FIR filtering can reduce the amount of algorithm calculation, improve operation efficiency, and reduce the hardware cost of the system. 2. According to claim 1, the rotary machinery fault diagnosis system for variable speed working conditions is characterized in that: the control and signal processor is composed of three parts: a frequency synthesis module, an angular domain signal processing module, and a feature extraction module. The frequency synthesis module receives the speed pulse signal and realizes real-time calculation of the speed according to the speed signal counter integrated inside. Then the real-time calculated speed is converted into a sampling frequency pulse, which is used to realize the real-time synchronous change of the sampling frequency and the speed, and an accurate angular domain signal can be obtained; the angular domain signal processing module includes a time domain-angular domain conversion and an angular domain signal low-pass filtering, wherein the time domain-angular domain conversion is used to convert the collected time domain signal into an angular domain signal, and the angular domain signal low-pass filtering is used to perform anti-aliasing filtering on the angular domain signal and eliminate high-order irrelevant components; the feature extraction is used to extract the prominent spectral lines in the order spectrum and compare them with the theoretical fault feature order to realize the fault diagnosis of the rotary machinery; the frequency synthesis module in the control and signal processor uses the internal hardware resources of the control chip and is realized by combining hardware and software, which can track the speed of the rotary machinery in real time, accurately, and over a large range, and reduce the system hardware usage cost. 3. The rotating machinery fault diagnosis system for variable speed working conditions according to claim 1 is characterized in that: the frequency synthesis module includes three parts: input, operation and output. The input includes system clock frequency fsys , speed pulse fep transmitted by speed detection _circuit and frequency multiplication _coefficient K , which is used to provide data, operation coefficient and reference frequency for operation, so that the system can accurately, real-time and continuously calculate the changing speed. The operation includes pulse counter, overflow counter, calculator and timer, which are used to calculate different output frequencies according to different input parameters. The output is used to provide sampling frequency pulse to time domain sampler. The module workflow includes four steps: step 1, reading and calculating parameters, which are used to calculate the speed according to the frequency multiplication coefficient K and sampling _{order Os} of monitoring equipment; step 2, speed frequency calculation, which is used to calculate the speed frequency according to the read speed signal pulse and the parameters in step 1; step 3, output sampling frequency pulse calculation, which is used to calculate the sampling frequency according to the speed frequency calculated in step 2, and then output sampling frequency pulse according to the sampling frequency calculation; the frequency synthesis module can improve the speed tracking accuracy and range and the continuity of speed pulse counting. 4. The rotating machinery fault diagnosis system for variable speed working conditions according to claim 1 is characterized in that: the angular domain signal low-pass filtering is used to perform anti-aliasing filtering and remove interference signals on the collected angular domain signals, which is divided into three steps: (1) reading the angular domain signal; (2) judging the setting mode. When it is the initial setting, the cutoff order _{Os is calculated according to the read sampling order Oclk} , and the two parameters are used to calculate the FIR filter _{coefficient hn} . When it is not the initial setting, the filter parameter update judgment is performed. If the filter parameter changes, the filter _coefficient hn is recalculated. If the filter parameter does not change, the next step is executed; (3) convolution operation is performed, and the calculation result is output; anti-aliasing filtering and interference signal removal of the angular domain signal can be realized.