Inertial navigation axial deviation correction method

Abstract

The application provides a kind of inertial navigation axial deviation correction method, comprising: obtaining north seeker and inertial navigation;Adjust the reference line of north seeker and inertial navigation to be consistent, read the first heading angle θ output by north seeker, and the first heading angle θ is the included angle between the reference line of north seeker and north direction;Obtain satellite positioning system, install satellite positioning system on inertial navigation;Get the second heading angle γ by satellite positioning system, and the second heading angle γ is the included angle between the reference line of satellite positioning system and north direction;Calculate error value a;According to error value a, calculate the actual heading output ψ of inertial navigation.The actual heading output ψ obtained in this way compensates for the deviation caused by the inconsistency between the reference line of satellite positioning system and the heading reference line of inertial navigation, makes the calculation result more accurate, reduces the system error, and improves the reliability of the system.

Description

Technical Field

[0001] This disclosure generally relates to the field of inertial navigation equipment technology, and specifically to an inertial navigation axial deviation correction method. Background Technology

[0002] Base sway can disturb the stability of the line-of-sight tracking system's target tracking. To achieve stable spatial line-of-sight pointing, the impact of base sway on line-of-sight stability must be eliminated. To obtain accurate data on moving base disturbance input, a combined navigation system of inertial navigation (MEMS gyroscope) and satellite positioning system is typically introduced, and the accuracy of the combined navigation system characterizes the target indication accuracy of the electro-optical tracking system.

[0003] In the aforementioned integrated navigation systems, due to limitations in inertial navigation system (INS) accuracy, gyroscope drift is comparable to ground speed, thus lacking the ability to automatically find north. This means the INS' heading accuracy relies on dynamic acceleration or satellite positioning heading reference. In practical electro-optical tracking systems, dynamic conditions are less pronounced, therefore a heading-dependent-satellite-positioning-heading-reference method is used. However, the reference lines of the satellite positioning system and the INS' heading baseline cannot be guaranteed to be perfectly parallel; installation deviations exist between them, directly affecting system accuracy. Summary of the Invention

[0004] In view of the above-mentioned defects or deficiencies in the prior art, it is desirable to provide an inertial navigation axial deviation correction method that can solve the above-mentioned technical problems.

[0005] This application provides a method for correcting axial deviation of an inertial navigation system, including:

[0006] Acquire north-finding instrument and inertial navigation system;

[0007] Adjust the north finder to align with the inertial navigation system's baseline, and read the first heading angle θ output by the north finder. The first heading angle θ is the angle between the north finder's baseline and the north direction.

[0008] Obtain a satellite positioning system and install the satellite positioning system on the inertial navigation system; obtain a second heading angle γ through the satellite positioning system, where the second heading angle γ is the angle between the reference line of the satellite positioning system and the north direction;

[0009] Calculate the error value a according to formula (1):

[0010] α = θ - γ (one);

[0011] Based on the error value a, the actual heading output ψ of the inertial navigation system is calculated.

[0012] According to the technical solution provided in the embodiments of this application, the method for correcting the heading output of the inertial navigation system using the error value a is as follows:

[0013] Obtain the real-time heading angle γ of the satellite positioning system t ;

[0014] The actual heading output ψ of the inertial navigation system is calculated according to formula (II):

[0015] ψ=γ t +a (two).

[0016] According to the technical solution provided in the embodiments of this application, the method for adjusting the reference line of the north finder and the inertial navigation system to be consistent is as follows: the north finder and the inertial navigation system are installed on the mounting platform through the same positioning mechanism so that the reference line of the north finder and the inertial navigation system are consistent.

[0017] According to the technical solution provided in the embodiments of this application, the positioning mechanism includes two positioning holes disposed on the mounting platform and positioning pins installed in the positioning holes.

[0018] According to the technical solution provided in the embodiments of this application, the inertial navigation axial deviation correction method further includes:

[0019] Calculate the accuracy value δψ1 of the north-finding instrument;

[0020] Calculate the accuracy value δψ2 of the positioning mechanism;

[0021] Calculate the systematic error δψ according to formula (iii):

[0022] δψ=δψ1+δψ2 (III).

[0023] According to the technical solution provided in the embodiments of this application, the method for calculating the accuracy value δψ1 of the north-finding instrument includes:

[0024] The north-finding instrument is mounted on a fixed platform using positioning components;

[0025] Acquire the theodolite and the north reference mirror, and adjust the first measuring line of the theodolite to be parallel to the normal direction of the north reference mirror;

[0026] Adjust the second measuring line of the theodolite to pass through the positioning element;

[0027] Read the angle ψ between the first measuring line and the second measuring line. a ;

[0028] Obtain the heading value ψ of the current position of the north-facing reference mirror. b The heading value ψ b The angle between the normal of the north-facing reference mirror and the north direction;

[0029] Obtain the heading value ψ of the north finder. c ;

[0030] Calculate the accuracy value δψ1 of the north-finding instrument according to formula (iv):

[0031] δψ1=ψ c -ψ a -ψ b (Four).

[0032] According to the technical solution provided in the embodiments of this application, the accuracy value δψ2 of the positioning mechanism is calculated according to formula (v):

[0033]

[0034] Where n1 and n2 represent the machining errors of the two locating pins, and m represents the distance between the two locating holes.

[0035] According to the technical solution provided in the embodiments of this application, the method for installing the satellite positioning system on the inertial navigation system is as follows: manually or mechanically adjust the reference line of the satellite positioning system to be basically parallel with the baseline of the inertial navigation system, and then fix the satellite positioning system on the inertial navigation system.

[0036] According to the technical solution provided in the embodiments of this application, the satellite positioning system has GPS dual antennas, and the reference line of the satellite positioning system is the line connecting the dual antennas.

[0037] The beneficial effects of this application are as follows: This application aims to solve the problem in the prior art where the reference line of the satellite positioning system and the heading reference line of the inertial navigation system are difficult to keep in sync, resulting in large system errors. This application introduces a north finder, utilizing the property that the north finder and the inertial navigation system are easy to adjust and align, to obtain the output result of the north finder (i.e., the first heading angle θ) and the second heading angle γ of the satellite positioning system, thereby obtaining the error value 'a' between the satellite positioning system and the inertial navigation system. Based on this error value 'a', the actual heading output ψ of the inertial navigation system can be calculated. The actual heading output ψ obtained in this way compensates for the deviation caused by the inconsistency between the reference line of the satellite positioning system and the heading reference line of the inertial navigation system, making the calculation results more accurate, reducing system errors, and improving the reliability of the system. Attached Figure Description

[0038] Other features, objects, and advantages of this application will become more apparent from the following detailed description of non-limiting embodiments with reference to the accompanying drawings:

[0039] Figure 1 A flowchart of an inertial navigation axial deviation correction method provided in this application;

[0040] Figure 2 This is a schematic diagram of the positioning mechanism;

[0041] Figure 3 for Figure 2The diagram shows a structure in which a positioning pin 3 is installed on the positioning hole 2.

[0042] 1. Mounting platform; 2. Positioning hole; 3. Positioning pin. Detailed Implementation

[0043] The present application will now be described in further detail with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and not intended to limit it. Furthermore, it should be noted that, for ease of description, only the parts relevant to the invention are shown in the accompanying drawings.

[0044] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. This application will now be described in detail with reference to the accompanying drawings and embodiments.

[0045] Please refer to Figure 1 The inertial navigation axial deviation correction method provided in this application includes:

[0046] S100: Acquire north-finding instrument and inertial navigation system;

[0047] S200: Adjust the north finder to be aligned with the reference line of the inertial navigation system, and read the first heading angle θ output by the north finder. The first heading angle θ is the angle between the reference line of the north finder and the north direction.

[0048] Specifically, after the north finder is adjusted, connect the test cable to power it, set the computer serial port, open the north finder host computer, load the north finder parameters, and then click the north finder button. The north finder will then find north and obtain the first heading angle θ, for example, θ = 84.4725°.

[0049] S300: Obtain a satellite positioning system and install the satellite positioning system on the inertial navigation system; obtain a second heading angle γ through the satellite positioning system, where the second heading angle γ is the angle between the reference line of the satellite positioning system and the north direction;

[0050] For example, at this time, the second heading angle γ = 81.5312°;

[0051] S400: Calculate the error value a according to formula (I):

[0052] α = θ - γ (one);

[0053] When the first heading angle θ = 84.4725° and the second heading angle γ = 81.5312°, the error value a = 2.9413° is obtained;

[0054] S500: Calculate the actual heading output ψ of the inertial navigation system based on the error value a.

[0055] Specifically, the satellite positioning system is a GPS navigation system. Preferably, the satellite positioning system has dual GPS antennas, and the reference line of the satellite positioning system is the line connecting the dual antennas.

[0056] Working Principle: This application aims to solve the problem in existing technologies where the reference line of the satellite positioning system and the heading baseline of the inertial navigation system (INS) are difficult to keep in sync, leading to large system errors. This application introduces a north-finding instrument, utilizing the ease with which the north-finding instrument and INS can be aligned. The output of the north-finding instrument (i.e., the first heading angle θ) and the second heading angle γ of the satellite positioning system are obtained, thus yielding the error value 'a' between the satellite positioning system and the INS. Based on this error value 'a', the actual heading output ψ of the INS can be calculated. The resulting actual heading output ψ compensates for the deviation caused by the inconsistency between the reference line of the satellite positioning system and the heading baseline of the INS, making the calculation results more accurate, reducing system errors, and improving system reliability.

[0057] In some embodiments, the method for correcting the heading output of the inertial navigation system using the error value a is as follows:

[0058] Obtain the real-time heading angle γ of the satellite positioning system t ;

[0059] The actual heading output ψ of the inertial navigation system is calculated according to formula (II):

[0060] ψ=γ t +a (two).

[0061] Specifically, real-time heading angle γ t This refers to the angle between the reference line and the north direction at the current location of the satellite positioning system.

[0062] In some embodiments, the method for aligning the north-finding instrument with the inertial navigation system's baseline is as follows: the north-finding instrument and the inertial navigation system are mounted on a mounting platform using the same positioning mechanism, so that the north-finding instrument and the inertial navigation system's baseline are aligned.

[0063] Furthermore, the specific method for aligning the north-finding instrument with the inertial navigation system's baseline is as follows:

[0064] The north finder is installed on the positioning mechanism on the mounting platform, and the first heading angle θ output by the north finder is read.

[0065] Remove the north-finding instrument from the mounting platform;

[0066] The inertial navigation system is mounted on the positioning mechanism at the same position.

[0067] Thus, through the positioning mechanism, the baselines of different inertial navigation systems and north-finding instruments can be quickly and accurately adjusted to be consistent during the adjustment process.

[0068] In some embodiments, the positioning mechanism includes two positioning holes 2 disposed on the mounting platform 1, and a positioning pin 3 installed in the positioning holes 2.

[0069] Specifically, the north finder is provided with a first pin hole corresponding to the positioning hole 2, and the connection of the two first pin holes is consistent with the baseline of the north finder; the inertial navigation system is provided with a second pin hole corresponding to the positioning hole 2, and the connection of the two second pin holes is consistent with the baseline of the inertial navigation system.

[0070] Specifically, the mounting platform 1 is provided with multiple fixing holes, which are used to fix the north finder or inertial navigation system.

[0071] Furthermore, the specific method for aligning the north-finding instrument with the inertial navigation system's baseline is as follows:

[0072] Align the two first pin holes on the north finder with the positioning hole 2, insert the positioning pin 3 into the positioning hole 2 to complete the positioning of the north finder, and then read the first heading angle θ output by the north finder.

[0073] Pull out the positioning pin 3 and remove the north finder from the mounting platform 1;

[0074] Align the two second pin holes on the inertial navigation system with the positioning hole 2, insert the positioning pin 3 into the positioning hole 2, and complete the positioning of the inertial navigation system, so that the north finder and the inertial navigation system are kept in line with the baseline.

[0075] Example 2

[0076] Based on Example 1, in some embodiments, the inertial navigation axial deviation correction method further includes:

[0077] Calculate the accuracy value δψ1 of the north-finding instrument;

[0078] Calculate the accuracy value δψ2 of the positioning mechanism;

[0079] Calculate the systematic error δψ according to formula (iii):

[0080] δψ=δψ1+δψ2 (III).

[0081] Specifically, the inertial navigation axial deviation correction method further includes: when the system error δψ is greater than the set value, replacing the north finder or positioning mechanism.

[0082] It should be further explained that the inertial navigation axial deviation correction method in Example 1 reduces system error and improves system reliability. The resulting actual heading output ψ meets the actual accuracy requirements.

[0083] In this embodiment, to further reduce the system error, the system error is obtained by calculating the accuracy values ​​of the north finder and the positioning mechanism. Based on the calculated system error, the north finder and the positioning mechanism can be selected and confirmed to meet the actual needs.

[0084] In some embodiments, the method for calculating the accuracy value δψ1 of the north-finding instrument includes:

[0085] The north-finding instrument is mounted on a fixed platform using positioning components;

[0086] Acquire the theodolite and the north reference mirror, and adjust the first measuring line of the theodolite to be parallel to the normal direction of the north reference mirror;

[0087] Adjust the second measuring line of the theodolite to pass through the positioning element;

[0088] Read the angle ψ between the first measuring line and the second measuring line. a ;

[0089] Obtain the heading value ψ of the current position of the north-facing reference mirror. b The heading value ψ b The angle between the normal of the north-facing reference mirror and the north direction;

[0090] Obtain the heading value ψ of the north finder. c ;

[0091] Calculate the accuracy value δψ1 of the north-finding instrument according to formula (iv):

[0092] δψ1=ψ c -ψ a -ψ b (Four).

[0093] In some embodiments, the accuracy value δψ2 of the positioning mechanism is calculated according to formula (v):

[0094]

[0095] Where n1 and n2 represent the machining errors of the two locating pins 3, and m represents the distance between the two locating holes 2. For ease of understanding, the machining error n1 of one of the locating pins 3 is shown in the figure;

[0096] In some embodiments, the method of installing the satellite positioning system on the inertial navigation system specifically involves: manually or mechanically adjusting the reference line of the satellite positioning system to be substantially parallel to the baseline of the inertial navigation system, and then fixing the satellite positioning system on the inertial navigation system.

[0097] It should be further explained that in the prior art, it is difficult to achieve absolute parallelism between the reference line of the satellite positioning system and the baseline of the inertial navigation system, which leads to deviations in the final calculation results. This application, on the other hand, takes into account the deviation between the reference line and the baseline, thereby compensating for the calculation results and improving the reliability of the system.

[0098] Therefore, the basic parallelism refers to the relative parallelism between the reference line and the baseline, which can be achieved through manual or mechanical adjustment.

[0099] The above description is merely a preferred embodiment of this application and an explanation of the technical principles employed. Those skilled in the art should understand that the scope of the invention involved in this application is not limited to technical solutions formed by specific combinations of the above-described technical features, but should also cover other technical solutions formed by arbitrary combinations of the above-described technical features or their equivalents without departing from the inventive concept. For example, technical solutions formed by substituting the above features with (but not limited to) technical features with similar functions disclosed in this application.

Claims

1. A method for correcting axial deviation of an inertial navigation system, characterized in that, include: Acquire north-finding instrument and inertial navigation system; Adjust the north-finding instrument to align with the inertial navigation system's baseline, and read the first heading angle output by the north-finding instrument. The first heading angle The angle between the baseline of the north-finding instrument and the north direction; Obtain a satellite positioning system and install the satellite positioning system on the inertial navigation system; obtain the second heading angle through the satellite positioning system. The second heading angle The angle between the reference line of the satellite positioning system and the north direction; Calculate the error value according to formula (1). a : (one); According to the error value a Calculate the actual heading output of the inertial navigation system. ; The method for aligning the north-finding instrument with the inertial navigation system's baseline is as follows: the north-finding instrument and the inertial navigation system are mounted on a mounting platform using the same positioning mechanism, so that the north-finding instrument and the inertial navigation system's baseline are aligned. Also includes: Calculate the accuracy value of the north finder. ; Calculate the accuracy value of the positioning mechanism. ; Calculate the systematic error according to formula (III). : (three); Calculate the accuracy value of the north finder. The methods include: The north-finding instrument is mounted on a fixed platform using positioning components; Acquire the theodolite and the north reference mirror, and adjust the first measuring line of the theodolite to be parallel to the normal direction of the north reference mirror; Adjust the second measuring line of the theodolite to pass through the positioning element; Read the angle between the first measuring line and the second measuring line. ; Obtain the heading value of the current position of the north-facing reference mirror. The heading value The angle between the normal of the north-facing reference mirror and the north direction; Obtain the heading value of the north finder. ; Calculate the accuracy value of the north-finding instrument according to formula (iv). : (Four); According to formula (five) to calculate the positioning mechanism precision value : (five); wherein n 1, n 2denotes the machining error of the two positioning pins, m denotes the distance between the two positioning holes.

2. The method according to claim 1, wherein, with the error value a The method for correcting the heading output of the inertial navigation system is: acquiring a real-time heading angle of the satellite positioning system ; According to formula (two) to calculate the actual heading output of the inertial navigation : (ii).

3. The method of claim 1, wherein, The positioning mechanism includes two positioning holes disposed on the mounting platform and positioning pins installed in the positioning holes.

4. The method of claim 1, wherein, The method for installing the satellite positioning system on the inertial navigation system is as follows: manually or mechanically adjust the reference line of the satellite positioning system to be basically parallel with the baseline of the inertial navigation system, and then fix the satellite positioning system on the inertial navigation system.

5. The method of claim 1, wherein, The satellite positioning system has dual GPS antennas, and the reference line of the satellite positioning system is the line connecting the dual antennas.

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