Noise processing method and device of inertial navigation system, medium and equipment

Abstract

The invention discloses a noise processing method and device of an inertial navigation system, a medium and equipment, and relates to the field of inertial navigation system.The method comprises the steps that a random vibration test is conducted on the inertial navigation system, and test data are obtained; performing noise frequency band testing on the test data under a low-pass filter with different initial cut-off frequencies, and determining a plurality of initial noise frequency band ranges; in each initial noise frequency band range, performing noise frequency band testing of notch filters with different initial frequencies on the test data to obtain a plurality of target noise frequency band ranges; the target noise frequency band range is a noise frequency band range generated by a frequency aliasing effect; in each target noise frequency band range, notch filter parameter design is carried out in the target noise frequency band range, and a target notch filter is obtained; and filtering noise signals output by the inertial navigation system by adopting a target notch filter. According to the method, the noise signal generated by the frequency aliasing effect in the inertial navigation system can be processed.

Description

Technical Field

[0001] The invention relates to the field of inertial navigation system design, and in particular to a noise processing method, device, medium and equipment for an inertial navigation system. Background Art

[0002] Inertial navigation systems based on micro-electro-mechanical systems (MEMS) have attracted more and more attention and are widely used in various fields due to their small size, high reliability and fully autonomous navigation characteristics. So far, MEMS inertial navigation systems are mostly connected to the equipment under test in the form of strapdown. Affected by the existing rigid connection relationship and the complex mechanical environment during use, the output noise of the inertial navigation system is relatively large, which seriously affects the solution accuracy of inertial navigation. Therefore, the way inertial navigation systems deal with external noise has become a key issue affecting the development of inertial navigation.

[0003] At present, the noise processing methods for inertial navigation systems generally include the following two methods: one is to design a physical shock-absorbing mechanism on the existing inertial navigation system, and then use the inertial navigation system after potting treatment, but the potting treatment greatly increases the risk of product use. Or the user adds shock-absorbing treatment on the contact surface between the inertial navigation system and the equipment when using it. The external shock-absorbing treatment of the inertial navigation system will greatly increase the design cost of the product; the second is to add a digital low-pass filter to the inertial navigation system to remove the high-frequency noise in the inertial navigation system, so that the inertial navigation system outputs a valid signal. This simple low-pass filtering method can achieve effective processing of ultra-high frequency signals to a certain extent, but it cannot process the noise signals generated by the frequency aliasing effect. And when the cut-off frequency of the low-pass filter is designed to be low, some effective signals will be filtered out, reducing the accuracy of navigation solution.

[0004] Therefore, there is an urgent need for a method that can process noise signals generated by frequency aliasing effects in an inertial navigation system. Summary of the invention

[0005] Based on this, it is necessary to provide a noise processing method, device, medium and equipment for an inertial navigation system to address the above technical problems. The method can process the noise signal generated by the frequency aliasing effect in the inertial navigation system.

[0006] The present invention adopts the following technical solutions:

[0007] The present invention provides a noise processing method for an inertial navigation system, comprising:

[0008] Conduct random vibration test on the inertial navigation system to obtain random vibration test data;

[0009] Perform noise frequency band tests on random vibration test data under low-pass filters with different initial cutoff frequencies to determine multiple initial noise frequency band ranges;

[0010] Under each initial noise frequency band range, the noise frequency band test of the notch filter with different initial frequencies is performed on the random vibration test data to obtain multiple target noise frequency band ranges; the target noise frequency band range is the noise frequency band range generated by the frequency aliasing effect.

[0011] In each target noise frequency band range, the parameters of the notch filter in the target noise frequency band range are designed to obtain the target notch filter; and the target notch filter is used to filter out the noise signal in the target noise frequency band range in the output data of the inertial navigation system.

[0012] Preferably, the random vibration test data is subjected to a noise frequency band test under a low-pass filter with different initial cutoff frequencies to determine multiple initial noise frequency band ranges, specifically including:

[0013] Obtaining an initial cutoff frequency of the low-pass filter and determining a transfer function of the low-pass filter at the initial cutoff frequency;

[0014] Input the random vibration test data into the designed low-pass filter, and record the time domain signal amplitude ratio of the random vibration test data before and after being processed by the low-pass filter;

[0015] adjusting an initial cutoff frequency of the low-pass filter by a first preset step size increment, and determining an updated low-pass filter transfer function corresponding to the initial cutoff frequency;

[0016] Input the random vibration test data into the low-pass filter after the initial cutoff frequency is updated, and record the time domain signal amplitude ratio of the random vibration test data before and after being processed by the low-pass filter after the initial cutoff frequency is updated;

[0017] When the initial cutoff frequency is greater than the output frequency of the inertial navigation system by a preset multiple, the time domain signal amplitude ratio under any adjacent initial cutoff frequency setting is compared. If the absolute value of the difference between the time domain signal amplitude ratios under adjacent initial cutoff frequency settings exceeds a first preset threshold, the frequency range between the adjacent initial cutoff frequencies is determined to be the initial noise frequency band range.

[0018] Preferably, in each initial noise frequency band range, the noise frequency band test of the notch filter with different initial frequencies is performed on the random vibration test data to obtain multiple target noise frequency band ranges, specifically including:

[0019] For any initial noise frequency band range, the minimum frequency within the initial noise frequency band range is used as the initial frequency of the notch filter;

[0020] Input the random vibration test data into the notch filter after parameter design, and record the time domain signal amplitude ratio of the random vibration test data before and after being processed by the notch filter;

[0021] Incrementally adjusting the initial frequency of the notch filter with a second preset step size to obtain a frequency-updated notch filter, inputting the random vibration test data into the frequency-updated notch filter, and recording the time domain signal amplitude ratio of the random vibration test data before and after being processed by the frequency-updated notch filter;

[0022] When the updated initial frequency is the maximum frequency within the initial noise frequency band, the time domain signal amplitude ratio under any adjacent initial frequency setting is compared. If the absolute value of the difference between the time domain signal amplitude ratios under adjacent initial frequency settings exceeds a second preset threshold, the frequency range between the adjacent initial frequencies is determined to be the target noise frequency band.

[0023] Preferably, the notch filter parameters include a first notch parameter and a second notch parameter. Under each target noise frequency band range, the notch filter parameter design under the target noise frequency band range is performed to obtain the target notch filter, specifically including:

[0024] For any target noise frequency band range, determine the center of the target noise frequency band range as the center frequency of the notch filter, and obtain a first initial value of a first notch parameter and a second initial value of a second notch parameter of the notch filter;

[0025] When the first initial value remains unchanged, the second initial value is adjusted with a third preset step size until the ratio of the filtered noise signal to the original output signal under the random vibration condition is minimized, and the second initial value corresponding to the minimum ratio of the filtered noise signal to the original output signal is determined as the value of the second notch parameter;

[0026] Maintaining the value of the second notch parameter, adjusting the first initial value with a third preset step size until the ratio of the filtered noise signal to the original output signal under the random vibration condition is minimized, and determining the first initial value corresponding to the minimum ratio of the filtered noise signal to the original output signal as the value of the first notch parameter;

[0027] A target notch filter is obtained according to the value of the first notch parameter and the value of the second notch parameter.

[0028] Preferably, adjusting the second initial value with a third preset step size until the ratio of the filtered noise signal to the original output signal under the random vibration condition is minimized comprises:

[0029] The second initial value is incrementally adjusted with a third preset step size. If the ratio of the filtered noise signal to the original output signal increases during the process of incrementally adjusting the second initial value, the second initial value is decrementally adjusted with the third preset step size until the ratio of the filtered noise signal to the original output signal shows a trend of increasing from a small value, and the adjustment of the second initial value is stopped.

[0030] Preferably, adjusting the first initial value with a third preset step size until the ratio of the filtered noise signal to the original output signal under the random vibration condition is minimized comprises:

[0031] The first initial value is incrementally adjusted with a third preset step size. If the ratio of the filtered noise signal to the original output signal increases during the process of incrementally adjusting the first initial value, the first initial value is decrementally adjusted with the third preset step size until the ratio of the filtered noise signal to the original output signal shows a trend of increasing from a small value, and the adjustment of the first initial value is stopped.

[0032] Preferably, the method further comprises:

[0033] After obtaining the target notch filter, a random vibration test is performed on the inertial navigation system to determine the noise processing performance of the target notch filter. The target notch filter is the noise processing part of the inertial navigation system.

[0034] The present invention provides a noise processing device for an inertial navigation system, comprising:

[0035] An acquisition module is used to obtain random vibration test data obtained by performing a random vibration test on an inertial navigation system;

[0036] The first processing module is used to perform a noise frequency band test on the random vibration test data under a low-pass filter with different initial cutoff frequencies to determine multiple initial noise frequency band ranges;

[0037] The second processing module is used to perform noise frequency band tests of notch filters with different initial frequencies on the random vibration test data in each initial noise frequency band range to obtain multiple target noise frequency band ranges; the target noise frequency band range is the noise frequency band range generated by the frequency aliasing effect;

[0038] The third processing module is used to design the parameters of the notch filter in each target noise frequency band to obtain the target notch filter; and use the target notch filter to filter out the noise signal in the target noise frequency band in the output data of the inertial navigation system.

[0039] The present invention provides a computer-readable storage medium, wherein the storage medium stores a computer program, and when the computer program is executed by a processor, the noise processing method of the inertial navigation system is implemented.

[0040] The present invention provides a computer device, comprising a memory, a processor and a computer program stored in the memory and executable on the processor. When the processor executes the program, the noise processing method of the inertial navigation system is implemented.

[0041] At least one of the above technical solutions adopted by the present invention can achieve the following beneficial effects:

[0042] Obtain random vibration test data obtained by performing random vibration tests on the inertial navigation system; perform noise band tests on the test data under low-pass filters with different initial cutoff frequencies to determine multiple initial noise band ranges; based on each initial noise band range, perform noise band tests on the random vibration test data under notch filters with different initial frequencies to obtain multiple target noise band ranges; the target noise band range is the noise band range generated by the frequency aliasing effect; perform notch filter parameter design under the target noise band range for each target noise band range, and the obtained notch filter is used to filter out the noise signal generated by the aliasing effect. The above technology can perform fixed-point processing on the noise generated by the frequency aliasing effect of the inertial navigation system by designing multiple low-pass filters with different initial cutoff frequencies and multiple notch filters with different initial frequencies, and more completely retain the effective signal output by the actual inertial navigation system. In addition, this method does not require structural or hardware changes to the existing inertial navigation system, and has strong engineering practical value. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0044] Figure 1 A schematic flow chart of a noise processing method for an inertial navigation system provided by the present invention;

[0045] Figure 2 A specific flow chart of a noise processing method for an inertial navigation system provided by the present invention;

[0046] Figure 3 A diagram of a noise processing device for an inertial navigation system provided by the present invention;

[0047] Figure 4 A schematic diagram of a computer device for a noise processing method for an inertial navigation system provided by the present invention. DETAILED DESCRIPTION

[0048] In order to make the purpose, technical solution and advantages of the present invention clearer, the technical solution of the present invention will be clearly and completely described below in conjunction with the specific embodiments of the present invention and the corresponding drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present invention.

[0049] The technical solutions provided by various embodiments of the present invention are described in detail below in conjunction with the accompanying drawings.

[0050] Figure 1 The present invention is a flow chart of a noise processing method for an inertial navigation system, which specifically includes the following steps:

[0051] S101: Perform a random vibration test on the inertial navigation system to obtain random vibration test data.

[0052] In an exemplary embodiment, the inertial navigation system is installed on a vibration table to perform a random vibration test, and the random vibration test data is recorded.

[0053] S102: Performing a noise frequency band test on the random vibration test data under a low-pass filter with different initial cutoff frequencies to determine multiple initial noise frequency band ranges.

[0054] In an exemplary embodiment, a noise band test is performed on random vibration test data under a low-pass filter with different initial cutoff frequencies to determine multiple initial noise frequency band ranges, specifically including: obtaining the initial cutoff frequency of the low-pass filter and determining the low-pass filter transfer function under the initial cutoff frequency; inputting the random vibration test data into the designed low-pass filter and recording the time domain signal amplitude ratio of the random vibration test data before and after being processed by the low-pass filter; adjusting the initial cutoff frequency of the low-pass filter by a first preset step increment and determining the low-pass filter transfer function after the corresponding initial cutoff frequency is updated; inputting the random vibration test data into the low-pass filter after the initial cutoff frequency is updated and recording the time domain signal amplitude ratio of the random vibration test data before and after being processed by the low-pass filter after the initial cutoff frequency is updated; when the initial cutoff frequency is greater than the output frequency of the inertial navigation system by a preset multiple, comparing the time domain signal amplitude ratio under any adjacent initial cutoff frequency setting, if the absolute value of the difference between the time domain signal amplitude ratios under the adjacent initial cutoff frequency settings exceeds the first preset threshold, determining the frequency range between the adjacent initial cutoff frequencies as the initial noise frequency band range.

[0055] Among them, the first preset step size, the first preset threshold value and the preset multiple can be set according to specific engineering practices; for example, the first preset step size is 10, the first preset threshold value is 1 / 3, and the preset multiple is 0.5.

[0056] Specifically, the basic model of noise filtering of the inertial navigation system is composed of a low-pass filter and multiple notch filters.

[0057] The low-pass filter usually adopts a second-order digital low-pass filter design method. The design transfer function of the second-order digital low-pass filter is shown in formula (1).

[0058]

[0059] Among them, U1(s) is the filter output signal, I1(s) is the filter input signal, ε is the low-pass filter design parameter, ω c Design the cutoff frequency for the low-pass filter.

[0060] The transfer function of the notch filter is shown in formula (2).

[0061]

[0062] Among them, ε1 and ε2 are the design parameters of the notch filter, ω cR is the design frequency of the notch filter.

[0063] The noise frequency band test is carried out on the random vibration test data of the inertial navigation system. According to the use environment requirements of the inertial navigation system, the noise signal test under the low-pass filter with different initial cutoff frequencies is carried out. Taking the first preset step size of 10, the preset multiple of 0.5, and the first preset threshold of 1 / 3 as an example, the test method is as follows:

[0064] (1) Determine the initial cutoff frequency ω1 of the low-pass filter and design the low-pass filter transfer function at this frequency, as shown in formula (1). In formula (1), ω c The value of is the initial cutoff frequency of the set low-pass filter.

[0065] (2) The random vibration test data of the inertial navigation system is passed through the designed low-pass filter, and the time domain signal amplitude ratio of the random vibration test data before and after filtering is recorded.

[0066] (3) Adjust the initial cutoff frequency of the low-pass filter to ω2=ω1+10, design the transfer function of the low-pass filter at this frequency, and record the time domain signal amplitude ratio of the random vibration test data before and after filtering after updating the initial cutoff frequency of the low-pass filter.

[0067] (4) The initial cutoff frequency of the low-pass filter is adjusted in increments of 10, and the low-pass filter transfer function corresponding to the updated initial cutoff frequency is determined. The time domain signal amplitude ratio of the random vibration test data before and after the frequency update is recorded until the initial cutoff frequency of the designed low-pass filter is greater than 0.5 times the output frequency of the inertial navigation system.

[0068] (5) Compare the time domain signal amplitude ratios before and after filtering of the random vibration test data of the inertial navigation system under different initial cutoff frequency settings. If the absolute value of the difference between the two ratios exceeds 1 / 3, it is considered that the output of the aliasing frequency noise is within this frequency band, that is, the frequency range between the two initial cutoff frequencies is determined as the initial noise frequency band.

[0069] For example, the initial cutoff frequencies of the selected low-pass filter are ω1, ω2, ω3 and ω4, respectively. When the absolute value of the difference between the time domain signal amplitude ratios under adjacent initial cutoff frequency settings exceeds the first preset threshold, the frequency range between adjacent initial frequencies is determined to be the initial noise frequency band range; for example, first compare whether the absolute value of the difference between the time domain signal amplitude ratios under ω1 and ω2 exceeds 1 / 3. If the absolute value of the difference between the time domain signal amplitude ratios under ω1 and ω2 exceeds 1 / 3, (ω1, ω2) is determined as the initial noise frequency band range; according to the same principle, ω2 and ω3, ω3 and ω4 are compared in turn to determine multiple initial noise ranges.

[0070] S103: Under each initial noise frequency band range, a noise frequency band test of a notch filter with different initial frequencies is performed on the random vibration test data to obtain a plurality of target noise frequency band ranges; the target noise frequency band range is a noise frequency band range generated by a frequency aliasing effect.

[0071] In an exemplary embodiment, in each initial noise frequency band range, the random vibration test data is subjected to a noise frequency band test of a notch filter with different initial frequencies to obtain a plurality of target noise frequency band ranges, specifically including: for any initial noise frequency band range, taking the minimum frequency in the initial noise frequency band range as the initial frequency of the notch filter; inputting the random vibration test data into the notch filter after parameter design, and recording the time domain signal amplitude ratio of the random vibration test data before and after the notch filter processing; adjusting the initial frequency of the notch filter by a second preset step increment to obtain the notch filter after frequency update, and inputting the random vibration test data into the notch filter after frequency update, and recording the time domain signal amplitude ratio of the random vibration test data before and after the notch filter processing after frequency update; when the updated initial frequency is the maximum frequency in the initial noise frequency band range, comparing the time domain signal amplitude ratio under any adjacent initial frequency setting, if the absolute value of the difference between the time domain signal amplitude ratios under the adjacent initial frequency settings exceeds the second preset threshold, determining the frequency range between the adjacent initial frequencies as the target noise frequency band range.

[0072] The second preset step size and the second preset threshold value may be set according to specific engineering practices. For example, the second preset step size may be 1, the second preset threshold value may be 1 / 5, and the second preset threshold value may be smaller than the first preset threshold value.

[0073] Specifically, the frequency band of the notch filter is designed. According to the multiple initial noise frequency band ranges determined in S102, the notch filter is designed for these fixed frequency bands. An initial noise frequency band range, a second preset step size of 1, and a second preset threshold of 1 / 5 are used as an example for explanation. The design method is as follows:

[0074] (1) According to the determined initial noise frequency band, the target noise frequency band of the inertial navigation system output is confirmed, and the initial frequency of the notch filter is determined as ω cR1 , and at the same time, the band parameters of the notch filter with a frequency band of 1 Hz are designed; the initial frequency is the minimum frequency within the initial noise frequency band.

[0075] (2) The random vibration test data is passed through the designed notch filter, and the time domain signal amplitude ratio of the random vibration test data before and after filtering is recorded.

[0076] (3) Update the initial frequency of the notch filter to ω cR2 =ω cR1 +1, and design a notch filter with a frequency band of 1 Hz, input the random vibration test data into the notch filter with updated frequency after parameter design, and record the time domain signal amplitude ratio of the random vibration test data before and after filtering.

[0077] (4) When the difference between the updated initial frequency and the initial frequency of the notch filter is 10, the frequency update is stopped.

[0078] It should be noted that, in this embodiment, the difference between the updated initial frequency and the initial frequency of the notch filter is 10. This is because the difference between the minimum and maximum values ​​in the initial noise frequency range is 10. In fact, the initial frequency is updated to the maximum frequency of the initial noise frequency range.

[0079] (5) If the absolute value of the difference between the time domain signal amplitude ratios under different initial frequency settings exceeds 1 / 5, the frequency range between the different initial frequencies is determined to be the target noise frequency band range.

[0080] For example, the initial frequencies of the selected notch filters are ω 11 ,ω 12 ,ω 13 and ω 14 , if the absolute value of the difference between the time domain signal amplitude ratios under adjacent initial frequency settings exceeds the second preset threshold, the frequency range between adjacent initial frequencies is determined to be the target noise frequency band range; for example, first compare ω 11 and ω 12 Whether the absolute value of the difference in the time domain signal amplitude ratio under the condition exceeds 1 / 5, if ω 11 and ω 12 If the absolute value of the difference between the time domain signal amplitude ratio under the condition exceeds 1 / 5, then (ω 11 ,ω 12 ) is determined as the target noise frequency band range; according to the same principle, ω is compared in turn 12 and ω 13 ,ω 13 and ω 14 , thereby determining multiple target noise ranges.

[0081] S104: Under each target noise frequency band range, a notch filter parameter design is performed under the target noise frequency band range to obtain a target notch filter; and the target notch filter is used to filter out noise signals within the target noise frequency band range in the output data of the inertial navigation system.

[0082] In an exemplary embodiment, the notch filter parameters include a first notch parameter and a second notch parameter. Under each target noise frequency band range, the notch filter parameters are designed under the target noise frequency band range to obtain a target notch filter, specifically including: for any target noise frequency band range, the center of the target noise frequency band range is determined as the center frequency of the notch filter, and a first initial value of the first notch parameter of the notch filter and a second initial value of the second notch parameter are obtained; when the first initial value remains unchanged, the second initial value is adjusted by a third preset step size until the ratio of the filtered noise signal to the original output signal under random vibration conditions is minimized, and the second initial value corresponding to the minimum ratio of the filtered noise signal to the original output signal under the minimum ratio is determined as the value of the second notch parameter; the value of the second notch parameter is kept unchanged, and the first initial value is adjusted by a third preset step size until the ratio of the filtered noise signal to the original output signal under random vibration conditions is minimized, and the first initial value corresponding to the minimum ratio of the filtered noise signal to the original output signal under the minimum ratio is determined as the value of the first notch parameter; and the target notch filter is obtained according to the value of the first notch parameter and the value of the second notch parameter.

[0083] Wherein, adjusting the second initial value with the third preset step length until the ratio of the filtered noise signal to the original output signal under the random vibration condition is the smallest includes: incrementally adjusting the second initial value with the third preset step length, if the ratio of the filtered noise signal to the original output signal increases during the incremental adjustment of the second initial value, then decrementally adjusting the second initial value with the third preset step length until the ratio of the filtered noise signal to the original output signal shows a trend of increasing from small to large, and then the adjustment of the second initial value is stopped. Adjusting the first initial value with the third preset step length until the ratio of the filtered noise signal to the original output signal under the random vibration condition is the smallest includes: incrementally adjusting the first initial value with the third preset step length, if the ratio of the filtered noise signal to the original output signal increases during the incremental adjustment of the first initial value, then decrementally adjusting the first initial value with the third preset step length until the ratio of the filtered noise signal to the original output signal shows a trend of increasing from small to large, and then the adjustment of the first initial value is stopped.

[0084] The value of the third preset step length can be set according to actual conditions and is not limited in this embodiment.

[0085] Specifically, according to the determined target noise frequency band range, a corresponding notch filter is designed to achieve noise removal for the inertial navigation system while completely retaining the effective signal of the inertial navigation system. Taking the third preset step size of 0.001 as an example, the notch filter parameters are set as follows:

[0086] (1) According to the determined target noise frequency band range, the midpoint of the target noise frequency band range is selected as the center frequency of the notch filter, and the first initial value ε1 of the first notch parameter and the second initial value ε2 of the second notch parameter of the notch filter are initialized at the same time.

[0087] (2) While keeping the first initial value ε1 unchanged, adjust the second initial value ε2 so that the ratio of the filtered noise signal to the original output signal under the random vibration condition is minimized. During the judgment process, if the ratio continues to increase, adjust ε2=ε2+0.001, otherwise adjust ε2=ε2-0.001 until the ratio of the filtered noise signal to the original signal under the random vibration condition shows a trend of increasing from a small value. Then stop adjusting the second initial value. At this time, the filtering effect is optimal. The second initial value corresponding to the minimum ratio of the filtered noise signal to the original output signal is determined as the value of the second notch parameter.

[0088] (3) After ε2 is adjusted, the value of the second notch parameter is kept unchanged. Similarly, the first initial value ε1 is adjusted according to the ratio before and after filtering. If the ratio continues to increase, ε1 is adjusted to ε1-0.001. Otherwise, ε1 is adjusted to ε1+0.001. When the ratio of the filtered noise signal to the original signal under the random vibration condition shows a trend of increasing from small to large, the adjustment of the first initial value is stopped. At this time, the filtering effect is optimal. The first initial value corresponding to the minimum ratio of the filtered noise signal to the original output signal is determined as the value of the first notch parameter.

[0089] (4) Complete the design of notch filters within multiple target noise frequency bands to obtain the target notch filters.

[0090] It should be noted that there may be multiple target notch filters, and the multiple notch filters are designed in series, and the noise signal is filtered by the multiple target notch filters designed in series; for example, the target notch filter includes a first target notch filter and a second target notch filter, and the original output signal output by the inertial navigation system can be input to the first target notch filter to obtain a first filtered signal output by the first target notch filter, and the first filtered signal is input to the second target notch filter to obtain a second filtered signal output by the second notch filter, and the second filtered signal is determined as the filtered noise signal output by the target filter.

[0091] In an exemplary embodiment, after obtaining the target notch filter, a random vibration test is performed on the inertial navigation system to determine the noise processing performance of the target notch filter. The target notch filter is the noise processing part of the inertial navigation system.

[0092] According to the determined notch filter design parameters, discrete programming design is carried out. The filter design parameters are shown in formula (4).

[0093]

[0094] According to the design results, the output calculation method of the inertial navigation system after noise processing is shown in formula (5).

[0095]

[0096] in, Δt is the discretization time step, is the output of the inertial navigation system noise processing at the current moment, Output of the inertial navigation system noise processing at the current moment is the input of the inertial navigation system noise processing at the previous moment, is the input of the inertial navigation system noise processing at the previous moment, is the output of the inertial navigation system noise processing at the previous moment, It is the output of the inertial navigation system noise processing at the previous moment.

[0097] In an exemplary embodiment, the following is provided: Figure 2 A specific flow chart of a noise processing method for an inertial navigation system is shown. Among them, the inertial navigation device is an inertial navigation system. Complete the setting of the basic filtering model of the inertial navigation system, including a digital low-pass filter and multiple notch filters; complete the random vibration test of the inertial navigation system on the vibration table; carry out frequency band testing according to the random vibration test data; initialize the cutoff frequency of the low-pass filter, increase the filter cutoff frequency in steps of 10 Hz, and record the input-output time domain signal amplitude ratio at each frequency; when the cutoff frequency is greater than 0.5 times the data output frequency, stop frequency updating; when the recorded input-output time domain signal amplitude ratio exceeds the set value, record the frequency band range and design the initial value of the notch filter; with 1 Hz A notch filter is designed with ε as the step size and 1 Hz as the notch frequency bandwidth, and the random vibration test data is input into the notch filter. The input and output time domain signal amplitude ratios are recorded. When the absolute value of the difference in the time domain signal amplitude ratios exceeds the set value, the frequency band range is confirmed to be the notch frequency range; the notch center frequency is confirmed, and ε1 is kept unchanged, and ε2 is adjusted. ε2 is updated with a step size of 0.001 until the filter output-input ratio is less than the threshold value; after ε2 is confirmed, ε2 is kept unchanged, and ε1 is adjusted with a step size of 0.001 until the filter output-input ratio is less than the threshold value; the noise filter model is discretized and programmed.

[0098] When applying the noise processing method of an inertial navigation system provided by the present invention, it is not necessary to Figure 1 The steps are executed in the order shown. The specific execution order of the steps can be determined according to needs, and the present invention does not limit this.

[0099] The above is a noise processing method of an inertial navigation system of the present invention. Based on the same idea, the present invention also provides a corresponding noise processing device of an inertial navigation system, such as Figure 3 shown.

[0100] Figure 3 A schematic diagram of a noise processing device for an inertial navigation system provided by the present invention includes:

[0101] An acquisition module 301 is used to acquire random vibration test data obtained by performing a random vibration test on an inertial navigation system;

[0102] The first processing module 302 is used to perform a noise frequency band test on the random vibration test data under a low-pass filter with different initial cutoff frequencies to determine multiple initial noise frequency band ranges;

[0103] The second processing module 303 is used to perform noise frequency band tests of notch filters with different initial frequencies on the random vibration test data in each initial noise frequency band range to obtain multiple target noise frequency band ranges; the target noise frequency band range is the noise frequency band range generated by the frequency aliasing effect;

[0104] The third processing module 304 is used to design the parameters of the notch filter in each target noise frequency band to obtain the target notch filter; and use the target notch filter to filter out the noise signal in the target noise frequency band in the output data of the inertial navigation system.

[0105] For the specific definition of a noise processing device for an inertial navigation system, please refer to the definition of a noise processing method for an inertial navigation system mentioned above, which will not be repeated here. Each module in the noise processing device of the above-mentioned inertial navigation system can be implemented in whole or in part by software, hardware and a combination thereof. The above-mentioned modules can be embedded in or independent of the processor in the computer device in the form of hardware, or can be stored in the memory of the computer device in the form of software, so that the processor can call and execute the operations corresponding to the above modules.

[0106] The present invention also provides a computer-readable storage medium, which stores a computer program, which can be used to execute the above Figure 1 A noise processing method for an inertial navigation system is provided.

[0107] The present invention also provides Figure 4 The structural diagram of the computer device shown in FIG. Figure 4As shown in the figure, at the hardware level, the computer device includes a processor, an internal bus, a network interface, a memory, and a non-volatile memory, and may also include other hardware required for the business. The processor reads the corresponding computer program from the non-volatile memory into the memory and then runs it to achieve the above Figure 1 A noise processing method for an inertial navigation system is provided.

[0108] Those skilled in the art can understand that all or part of the processes in the above-mentioned embodiment methods can be completed by instructing the relevant hardware through a computer program, and the computer program can be stored in a non-volatile computer-readable storage medium. When the computer program is executed, it can include the processes of the embodiments of the above-mentioned methods. Among them, any reference to memory, storage, database or other media used in the embodiments provided by the present invention can include at least one of non-volatile and volatile memory. Non-volatile memory can include read-only memory (ROM), magnetic tape, floppy disk, flash memory or optical memory, etc. Volatile memory can include random access memory (RAM) or external cache memory. As an illustration and not limitation, RAM can be in various forms, such as static random access memory (SRAM) or dynamic random access memory (DRAM).

[0109] The technical features of the above embodiments may be arbitrarily combined. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of the present invention.

Claims

1. A noise processing method for an inertial navigation system, characterized in that: include: Conduct random vibration test on the inertial navigation system to obtain random vibration test data; Performing a noise frequency band test on the random vibration test data under a low-pass filter with different initial cutoff frequencies to determine multiple initial noise frequency band ranges; Under each initial noise frequency band range, a noise frequency band test of a notch filter with different initial frequencies is performed on the random vibration test data to obtain a plurality of target noise frequency band ranges; the target noise frequency band range is a noise frequency band range generated by a frequency aliasing effect; In each target noise frequency band range, a notch filter parameter design is performed in the target noise frequency band range to obtain a target notch filter; and the target notch filter is used to filter out noise signals in the target noise frequency band range in the output data of the inertial navigation system.

2. The method according to claim 1, characterized in that The random vibration test data is subjected to a noise frequency band test under a low-pass filter with different initial cutoff frequencies to determine multiple initial noise frequency band ranges, specifically including: Obtaining an initial cutoff frequency of the low-pass filter, and determining a transfer function of the low-pass filter at the initial cutoff frequency; Inputting the random vibration test data into the designed low-pass filter, and recording the time domain signal amplitude ratio of the random vibration test data before and after being processed by the low-pass filter; adjusting an initial cutoff frequency of the low-pass filter by a first preset step size increment, and determining an updated low-pass filter transfer function corresponding to the initial cutoff frequency; Inputting the random vibration test data into a low-pass filter after the initial cutoff frequency is updated, and recording the time domain signal amplitude ratio of the random vibration test data before and after being processed by the low-pass filter after the initial cutoff frequency is updated; When the initial cutoff frequency is greater than a preset multiple of the output frequency of the inertial navigation system, the time domain signal amplitude ratio under any adjacent initial cutoff frequency setting is compared. If the absolute value of the difference between the time domain signal amplitude ratios under adjacent initial cutoff frequency settings exceeds a first preset threshold, the frequency range between the adjacent initial cutoff frequencies is determined to be the initial noise frequency band range.

3. The method according to claim 1, characterized in that In each initial noise frequency band range, the random vibration test data is subjected to noise frequency band tests of notch filters with different initial frequencies to obtain multiple target noise frequency band ranges, specifically including: For any initial noise frequency band range, taking the minimum frequency within the initial noise frequency band range as the initial frequency of the notch filter; Inputting the random vibration test data into a notch filter after parameter design, and recording the time domain signal amplitude ratio of the random vibration test data before and after being processed by the notch filter; Incrementally adjusting the initial frequency of the notch filter with a second preset step size to obtain a notch filter with an updated frequency, inputting the random vibration test data into the notch filter with an updated frequency, and recording the time domain signal amplitude ratio of the random vibration test data before and after being processed by the notch filter with an updated frequency; When the updated initial frequency is the maximum frequency within the initial noise frequency band, the time domain signal amplitude ratio under any adjacent initial frequency setting is compared. If the absolute value of the difference between the time domain signal amplitude ratios under adjacent initial frequency settings exceeds a second preset threshold, the frequency range between the adjacent initial frequencies is determined to be the target noise frequency band.

4. The method according to claim 1, characterized in that The notch filter parameters include a first notch parameter and a second notch parameter. Under each target noise frequency band range, the notch filter parameter design under the target noise frequency band range is performed to obtain a target notch filter, including: For any target noise frequency band range, determine the center of the target noise frequency band range as the center frequency of the notch filter, and obtain a first initial value of a first notch parameter and a second initial value of a second notch parameter of the notch filter; When the first initial value remains unchanged, the second initial value is adjusted with a third preset step size until the ratio of the filtered noise signal to the original output signal under the random vibration condition is minimized, and the second initial value corresponding to the minimum ratio of the filtered noise signal to the original output signal is determined as the value of the second notch parameter; Keeping the value of the second notch parameter unchanged, adjusting the first initial value with the third preset step size until the ratio of the filtered noise signal to the original output signal under the random vibration condition is minimized, and determining the first initial value corresponding to the minimum ratio of the filtered noise signal to the original output signal as the value of the first notch parameter; The target notch filter is obtained according to the value of the first notch parameter and the value of the second notch parameter.

5. The method according to claim 4, characterized in that The step of adjusting the second initial value with a third preset step length until the ratio of the filtered noise signal to the original output signal under the random vibration condition is minimized includes: The second initial value is incrementally adjusted with the third preset step size. If the ratio of the filtered noise signal to the original output signal increases during the process of incrementally adjusting the second initial value, the second initial value is decrementally adjusted with the third preset step size until the ratio of the filtered noise signal to the original output signal shows a trend of increasing from a small value, and then the adjustment of the second initial value is stopped.

6. The method according to claim 4, characterized in that The first initial value is adjusted with the third preset step length until the ratio of the filtered noise signal to the original output signal under the random vibration condition is minimized, comprising: The first initial value is incrementally adjusted with the third preset step size. If the ratio of the filtered noise signal to the original output signal increases during the process of incrementally adjusting the first initial value, the first initial value is decrementally adjusted with the third preset step size until the ratio of the filtered noise signal to the original output signal shows a trend of increasing from a small value, and then the adjustment of the first initial value is stopped.

7. The method according to claim 1, characterized in that The method further comprises: After obtaining the target notch filter, a random vibration test is performed on the inertial navigation system to determine the noise processing performance of the target notch filter, where the target notch filter is a noise processing part of the inertial navigation system.

8. A noise processing device for an inertial navigation system, characterized in that: include: An acquisition module is used to obtain random vibration test data obtained by performing a random vibration test on an inertial navigation system; A first processing module is used to perform a noise frequency band test on the random vibration test data under a low-pass filter with different initial cutoff frequencies to determine multiple initial noise frequency band ranges; A second processing module is used to perform a noise frequency band test of a notch filter with different initial frequencies on the random vibration test data in each initial noise frequency band range to obtain a plurality of target noise frequency band ranges; A third processing module is used to design the parameters of a notch filter in each target noise frequency band to obtain a target notch filter; The target notch filter is used to filter out noise signals within the target noise frequency band in the output data of the inertial navigation system.

9. A computer-readable storage medium, characterized in that: The storage medium stores a computer program, and when the computer program is executed by a processor, the method according to any one of claims 1 to 7 is implemented.

10. A computer device, characterized in that: The method comprises a memory, a processor and a computer program stored in the memory and executable on the processor, wherein when the processor executes the program, the method according to any one of claims 1 to 7 is implemented.

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