An accurate estimation method for inertial navigation oscillation error based on multi-inertial navigation mutual observation

Abstract

The present invention relates to a method for accurately estimating the inertial navigation oscillation error based on multi-inertial navigation mutual observation. By using multiple sets of inertial navigation information, the change of the earth period oscillation term in the relative error of the latitude of each inertial navigation and other inertial navigations is observed. When it is observed that the amplitudes of the oscillation terms in the relative error of a certain inertial navigation and all other inertial navigations have changed, the phase of the latitude oscillation error term of this inertial navigation is calculated according to the change amount, and the phase of the latitude oscillation error term of another inertial navigation is continuously observed and obtained; the amplitudes of the latitude oscillation error terms of each inertial navigation are calculated according to the phase and latitude difference information of the two sets of inertial navigation oscillation terms; furthermore, the amplitudes and phases of the latitude oscillation error terms of other inertial navigations are calculated; finally, the amplitudes and phases of the longitude and heading oscillation error terms of all inertial navigations are calculated. Based on the long-term change characteristics of the inertial navigation oscillation error, this method obtains the information of the oscillation error terms of each inertial navigation from the multi-inertial navigation mutual observation in an autonomous manner, and the quality of the inertial navigation information can be significantly improved after compensation.

Description

Technical Field

[0001] The present invention belongs to the technical field of inertial navigation, and particularly relates to a method for accurately estimating the inertial oscillation error based on multi-inertial navigation mutual observation. Background Art

[0002] Inertial navigation is the main autonomous navigation means for underwater platforms. An inertial navigation system, based on Newton's inertial principle, establishes an inertial coordinate system by gyroscopes, and accelerometers measure the acceleration of the carrier. Through integral calculation, multi-parameter information such as the position, velocity, level, and heading of the carrier is obtained. In the solution of the inertial navigation system, the gravity vector and the earth rotation vector are used to form a closed-loop feedback of the latitude and horizontal and heading errors. The position error of a high-precision inertial navigation system oscillates and diverges over time: among them, the latitude error is a constant plus an oscillating error, and the amplitude of oscillation shows an increasing trend over time; the longitude error is a diverging error over time, superimposed with a small amplitude oscillation.

[0003] The oscillating error of the inertial navigation system is mainly the earth periodic oscillating error, which has an important impact on the quality of the output information of the inertial navigation. At present, there is a lack of means to estimate the inertial oscillating error only based on autonomous navigation information. Therefore, this patent proposes a method for estimating the inertial oscillating error only relying on the inertial autonomous information of multiple sets of inertial navigations, which can significantly improve the autonomous navigation ability of underwater platforms. Summary of the Invention

[0004] In view of the fact that the existence of the earth periodic oscillating error is an inherent characteristic of inertial navigation equipment, in the long-term underwater application scenarios where it is difficult to obtain external position reference information, the earth periodic oscillating error will seriously affect the quality of the navigation information of underwater platforms. The purpose of the present invention is to overcome the deficiencies of the prior art and provide a method for accurately estimating the error of the earth periodic oscillation term of the inertial navigation based on the mutual observation of multiple sets of inertial navigations. According to the long-term variation characteristics of the inertial oscillating error, this method separates and extracts the oscillating error terms of each inertial navigation from the mutual observation of multiple sets of inertial navigations, and improves the quality of the output information of the inertial navigation system in a completely autonomous manner. Applying it to underwater platforms will significantly improve the long-term autonomous navigation ability of the platforms.

[0005] The technical solution adopted by the present invention is as follows: A method for accurately estimating the inertial oscillating error based on multi-inertial navigation mutual observation, the method is implemented based on multiple sets of inertial navigation devices, hereinafter referred to as inertial navigations for short, and includes the following steps:

[0006] Step 1: n sets of inertial navigations G with known relative positions i , i = 1, 2,... n, the latitude output information is L i (t), i = 1, 2,... n, t is time. For the inertial navigation G i , calculate the inertial navigation G i and the inertial navigation G j , j = 1, 2,... n and j ≠ i, the latitude output difference Li,j L(t) = L j L(t) - L i Extract L(t) i,j Amplitude A of the Earth's periodic oscillation term in the L(t) signal i,j and phase

[0007] Step 2: For inertial navigation G i where i = 1, 2, … n, observe the corresponding A i,j , j = 1, 2, … n and j ≠ i for the variation with time, at time t 1 When the inertial navigation corresponding to j = 1, 2, … n and j ≠ m 1 shows a significant change, then calculate the phase of the Earth's periodic oscillation error term of the inertial navigation latitude based on the variation of the Earth's periodic oscillation error term phase of the Earth's periodic oscillation error term of the latitude

[0008] Step 3: Continue to observe inertial navigation G i where i = 1, 2, … n, and i ≠ m 1 for the corresponding A i,j , j = 1, 2, … n and j ≠ i for the variation with time. When at time t 2 the inertial navigation corresponding to j = 1, 2, … n and j ≠ m 2 all show significant changes, then calculate the phase of the Earth's periodic oscillation error term of the inertial navigation latitude based on the variation of the Earth's periodic oscillation error term phase of the Earth's periodic oscillation error term of the latitude

[0009] Step 4: Calculate the amplitude of the Earth's periodic oscillation error term of the inertial navigation phase of the Earth's periodic oscillation error term of the latitude inertial navigation phase of the Earth's periodic oscillation error term of the latitude and inertial navigation latitude difference information Calculate the inertial navigation amplitude of the Earth's periodic oscillation error term of the latitude and inertial navigation amplitude of the Earth's periodic oscillation error term of the latitude

[0010] Step 5: Calculate inertial navigation G based on where i = 1, 2, … n, and i ≠ m i , i ≠ m 1 , i ≠ m 2Amplitude A of the latitude earth periodic oscillation error term i , phase

[0011] Step 6: Based on the inertial navigation G i , i = 1, 2, … n, the amplitude A of the latitude earth periodic oscillation error term i , phase Obtain the inertial navigation G i , i = 1, 2, … n, the amplitude and phase information of the longitude and heading earth periodic oscillation error terms;

[0012] Through Steps 1 to 6, the accurate estimation of the longitude, latitude, and heading earth periodic oscillation error terms of multiple sets of inertial navigation is achieved. The n sets of inertial navigation described in Step 1 satisfy n ≥ 3.

[0013] The obvious change described in Step 2 is that when all j = 1, 2, … n and j ≠ m 1 terms increase or decrease by a value simultaneously, it is determined that the amplitude of the inertial navigation earth periodic oscillation error term has changed.

[0014] The calculation of the inertial navigation latitude earth periodic oscillation error term phase includes the following steps:

[0015] 1) Observe the inertial navigation G 1 before and after the moment t i , i = 1, 2, … n and i ≠ m 1 corresponding to the change situation of A i,j , j = 1, 2, … n and j ≠ i, select the inertial navigation G with the smallest corresponding A i,j change, determine that the oscillation error of the inertial navigation G s has not changed, and extract the inertial navigation G s before the moment t 1 and s and the amplitude of the earth periodic oscillation term in the latitude difference information phase at the moment t 1 the inertial navigation G s and the amplitude of the earth periodic oscillation term in the latitude difference information phase

[0016] 2) Calculate the inertial navigation earth periodic oscillation error term phase

[0017]

[0018] Arctan is the arctangent function.

[0019] The inertial navigation calculation described in step 4 Amplitude of the latitude Earth periodic oscillation error term and inertial navigation Amplitude of the latitude Earth periodic oscillation error term includes the following steps:

[0020] 1) According to t 2 The inertial navigation at the moment and The latitude difference information Extract The amplitude of the Earth periodic oscillation term in and the phase

[0021] 2) Calculate the inertial navigation Amplitude of the Earth periodic oscillation error term

[0022]

[0023] 3) Calculate the inertial navigation G m2 Amplitude A of the Earth periodic oscillation error term m2 :

[0024]

[0025] The method for calculating the inertial navigation G i , i = 1, 2, … n, and i ≠ m 1 , i ≠ m 2 Amplitude A of the latitude Earth periodic oscillation error term i and phase is as follows:

[0026]

[0027] The advantages and positive effects of the present invention are as follows: The working principle of inertial navigation determines that there are earth periodic oscillation errors in its output navigation information, and this oscillatory divergence error seriously affects the quality of inertial navigation information. At present, the methods of estimating and compensating inertial navigation errors using external navigation reference information such as satellite navigation are limited in underwater and other scenarios, and there is an urgent need to explore an autonomous estimation method for inertial navigation errors applicable to underwater. The present invention utilizes the characteristics that the amplitude of the earth periodic oscillation error of inertial navigation diverges and the phase is relatively stable. By observing the changes in the relative errors of multiple sets of inertial navigation, the divergence change of the earth periodic oscillation error of inertial navigation is judged, and then the phase information of the earth periodic oscillation error is obtained; furthermore, using the phase information of the earth periodic oscillation error of two sets of inertial navigation, the earth periodic oscillation error of each set of inertial navigation is decomposed from the earth periodic oscillation terms of the relative errors of the two sets of inertial navigation, realizing the accurate estimation of the earth periodic oscillation terms of inertial navigation and significantly improving the quality of the output information of inertial navigation. This method only requires the navigation information of multiple sets of inertial navigation, has the characteristics of complete autonomy and concealment, is applicable to underwater and other scenarios where satellite navigation information is denied, and significantly improves the long-term concealment and autonomous navigation capabilities of underwater platforms. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Figure 1 is the inertial navigation of the present invention Schematic diagram of phase resolution of earth periodic oscillation error term;

[0029] Figure 2 is the inertial navigation of the present invention and Schematic diagram of amplitude resolution of earth periodic oscillation error term. DETAILED DESCRIPTION OF THE INVENTION

[0030] The present invention will be further described in detail below through specific embodiments. The following embodiments are only descriptive and not restrictive, and the protection scope of the present invention cannot be limited thereby.

[0031] Embodiment 1, an accurate estimation method for inertial navigation oscillation error based on multi-inertial navigation mutual observation, includes the following steps:

[0032] Step 1: n sets of inertial navigation G installed on the same platform or different platforms but with known relative positions i , i = 1, 2,... n, the latitude output information is L i (t), i = 1, 2,... n, n ≥ 3, t is time. For inertial navigation G i , calculate the latitude difference L between inertial navigation G i and inertial navigation G j , j = 1, 2,... n and j ≠ i as L i,j (t) = L j (t) - L i (t), extract the amplitude A of the earth periodic oscillation term in the L i,j (t) signal i,j , phase Ai,j As shown in Table 1, the cells in the first column of Table 1 correspond to G i , i = 1, 2, ... n, the first row of cells corresponds to the inertial navigation G j , j=1,2,…n and ≠i, the cell in the i+1th row and j+1th column is the inertial navigation G i and inertial navigation G j The amplitude of the earth period oscillation term A in the latitude difference i,j .

[0033] Table 1 Amplitude of the Earth period oscillation term A in the difference between two inertial navigation latitudes ij surface

[0034] <![CDATA[Inertial Navigation G 1 > <![CDATA[Inertial Navigation G 2 > <![CDATA[Inertial Navigation G 3 > ... <![CDATA[Inertial Navigation G n > <![CDATA[Inertial Navigation G 1 > / <![CDATA[A 1,2 > <![CDATA[A 1,3 > <![CDATA[A 1,n > <![CDATA[Inertial Navigation G 2 > <![CDATA[A 2,1 > / <![CDATA[A 2,3 > <![CDATA[A 2,n > <![CDATA[Inertial Navigation G 3 > <![CDATA[A 3,1 > <![CDATA[A 3,2 > / <![CDATA[A 3,n > ... / <![CDATA[Inertial Navigation G n > <![CDATA[A n,1 > <![CDATA[A n,2 > <![CDATA[A n,3 > /

[0035] Step 2: For the inertial navigation G i , i = 1, 2, ... n, observe the corresponding A every 1-2 days i,j ,j=1,2,…n and j≠i changes over time, t 1 Observe the inertial navigation Corresponding j=1,2,…n and j≠m 1 Obvious changes occur, and obvious changes refer to all When both items increase or decrease by a value, the inertial navigation The amplitude of the earth period oscillation error term has changed. This is because the inherent error characteristics of the inertial navigation system determine that the phase of the earth period oscillation error term of the inertial navigation system is relatively stable, but the amplitude may change, mainly manifested as a gradual increase over time. Calculation of the variation of the error term of the earth period oscillation in latitude Latitude Earth Period Oscillation Error Term Phase Computational Inertial Navigation Earth period oscillation error term phase The process diagram is as follows Figure 1 As shown, the steps are as follows:

[0036] 1) Observation t 1 Time before and after inertial navigation G i ,i=1,2,…n and i≠m 1 Corresponding to A i,j ,j=1,2,…n and j≠i, select the corresponding A i,j Minimum change in inertial navigation G s , determine the inertial navigation G s The oscillation error of i,j The specific method of determining the "minimum change" is to obtain S i =A i,1 +A i,2 +…+Ai,i-1 +A i,i+1 +…+A i,n In the inertial navigation G i where i = 1, 2, …, n and i ≠ m 1 corresponding to S i The inertial navigation with the smallest value is the inertial navigation G s Extract the inertial navigation G 1 - 2 days before time t 1 and s and the amplitude of the earth periodic oscillation term in the latitude difference information phase t 1 the inertial navigation G at time t s and the amplitude of the earth periodic oscillation term in the latitude difference information phase Figure 1 In it, make a vector sm′ with an amplitude of and a phase of and make a vector sm″ with an amplitude of 1 and a phase of phase 1 .

[0037] 2) Figure 1 Connect m′ 1 , m″ 1 to make a vector m′ 1 m″ 1 The angle between the vector m′ 1 m″ 1 and the x - axis is the phase of the earth periodic oscillation error term of the inertial navigation The phase calculation formula is as follows: phase The calculation formula is as follows:

[0038]

[0039] Step 3: Continue to observe the inertial navigation G i where i = 1, 2, …, n, and i ≠ m 1 corresponding A i,j , j = 1, 2, …, n and j ≠ i as it changes with time. When at time t 2 it is observed that the inertial navigation corresponding to j = 1, 2, …, n and j ≠ m 2 all change significantly, it is determined that the amplitude of the earth periodic oscillation error term of the inertial navigation has changed. Calculate the phase of the earth periodic oscillation error term of the inertial navigation according to the change amount of the earth periodic oscillation error term of the latitude of the inertial navigation The calculation steps are as follows: The phase of the earth periodic oscillation error term of the latitude of the inertial navigation The calculation steps are as follows:​

[0040] 1) Observation t 2 Time before and after inertial navigation G i ,i=1,2,…n and i≠m 2 Corresponding to A i,j ,j=1,2,…n and j≠i, choose A i,j Minimum change in inertial navigation G r , determine the inertial navigation G r The oscillation error of i,j The specific method of determining the "minimum change" is to obtain S i =A i,1 +A i,2 +…+A i,i-1 +A i,i+1 +…+A i,n , in the inertial navigation G i ,i=1,2,…n and i≠m 2 Corresponding to S i The smallest inertial navigation is the inertial navigation G r Extraction 2 1-2 days before the time of the inertial navigation G r and Amplitude of the Earth's Periodic Oscillation Term in Latitude Difference Information Phase t 2 Time Inertial Navigation G r and Amplitude of the Earth's Periodic Oscillation Term in Latitude Difference Information Phase

[0041] 2) Calculate inertial navigation Earth period oscillation error term phase

[0042]

[0043] Step 4: According to t 2 Time Inertial Navigation Latitude Earth Period Oscillation Error Term Phase Inertial Navigation Latitude Earth Period Oscillation Error Term Phase And inertial navigation Latitude difference information Computational Inertial Navigation Amplitude of the error term of the latitudinal Earth period oscillation and inertial navigation Amplitude of the error term of the latitudinal Earth period oscillation Inertial Navigation Amplitude of the Earth's Periodic Oscillation Term in Latitude Difference Decompose to get The schematic diagram of the solution process is as shown in Figure 2 the following, and the specific steps are as follows:

[0044] 1) According to the latitude difference information between the inertial navigation at 2 time t and extract the amplitude of the Earth periodic oscillation term and the phase in Figure 2 and construct a vector m″ with an amplitude of and a phase of in 1 m″ 2 . Draw a straight line passing through point m″ 1 and making an angle of with the x-axis, and draw a straight line passing through point m″ 2 and making an angle of with the x-axis. The two lines intersect at point O.

[0045] 2) The length of the line segment from point O to point m″ 1 is the amplitude of the Earth periodic oscillation error term of the inertial navigation . The calculation formula is as follows

[0046] 3) The length of the line segment from point O to point m″ 2 is the amplitude of the Earth periodic oscillation error term of the inertial navigation . The calculation formula is as follows

[0047] Step 5: According to the of the inertial navigation and the inertial navigation and G i , i = 1, 2, … n, and i ≠ m 1 , i ≠ m 2 calculate the amplitude and phase of the Earth periodic oscillation term in the latitude difference of the inertial navigation G i to calculate the amplitude A i and phase of the Earth periodic oscillation error term of the latitude of the inertial navigation G

[0048]

[0049]

[0050] Step 6: Based on the amplitude A i of the Earth periodic oscillation error term of the latitude of the inertial navigation G i , i = 1, 2, … n, phase Based on the relationship between the inertial navigation longitude, heading and the Earth period oscillation error of latitude, the inertial navigation G is obtained. i The amplitude and phase information of the Earth period oscillation error terms of longitude and heading.

[0051] Through steps 1 - 6, an accurate estimation method of inertial navigation oscillation error based on multi-inertial navigation mutual observation realizes the accurate estimation of the Earth period oscillation error terms of longitude, latitude and heading of multiple sets of inertial navigation.

Claims

1. An accurate estimation method for inertial navigation oscillation error based on multi-inertial navigation mutual observation. The method is implemented based on multiple sets of inertial navigation devices, hereinafter referred to as inertial navigation for short. Characterized in that: It includes the following steps: Step 1: n sets of inertial navigation systems G with known relative positions i , where the latitude output information for i = 1, 2, … n is L i (t), i = 1, 2, … n, and t is time. For the inertial navigation system G i , calculate the difference in latitude output between the inertial navigation system G i and the inertial navigation system G j , where j = 1, 2, … n and j ≠ i. The latitude output difference L i,j (t) = L j (t) - L i (t). Extract the amplitude A i,j of the Earth periodic oscillation term in the L i,j signal, and the phase Step 2: For the inertial navigation G i , for i = 1, 2, … n, observe the corresponding A i,j , where j = 1, 2, … n and j ≠ i, and observe the variation with time. At time t 1 , observe the inertial navigation corresponding and j ≠ m 1 has changed significantly. Then, calculate the phase of the latitude earth periodic oscillation error term of the inertial navigation according to the change amount of the latitude earth periodic oscillation error term of the inertial navigation latitude earth periodic oscillation error term ​ Step 3: Continue to observe inertial navigation G i , i = 1, 2, … n, and i ≠ m 1 The corresponding A i,j , j = 1, 2, … n and j ≠ i change with time. When t 2 At the moment, observe the inertial navigation Corresponding And j ≠ m 2 All show obvious changes, then according to the inertial navigation Calculate the inertial navigation based on the change amount of the latitude earth periodic oscillation error term Phase of the latitude earth periodic oscillation error term Step 4: According to the inertial navigation Latitude Earth periodic oscillation error term phase Inertial navigation Latitude Earth periodic oscillation error term phase And the inertial navigation Latitude difference information Calculate the inertial navigation Latitude Earth periodic oscillation error term amplitude And the inertial navigation Latitude Earth periodic oscillation error term amplitude Step 5: According to the inertial navigation of calculate the inertial navigation G i , i = 1, 2, … n, and i ≠ m 1 , i ≠ m 2 amplitude A of the latitude earth periodic oscillation error term i and phase Step 6: Based on inertial navigation G i , where i = 1, 2, … n, the amplitude A of the latitude Earth periodic oscillation error term i and phase to obtain inertial navigation G i , where i = 1, 2, … n, the amplitude and phase information of the longitude and course Earth periodic oscillation error terms; Through steps 1 to 6, accurate estimation of the earth periodic oscillation error terms of longitude, latitude, and heading of multiple sets of inertial navigation is achieved.

2. The accurate estimation method for inertial navigation oscillation error based on multi-inertial navigation mutual observation according to claim 1, Characterized in that: The n sets of inertial navigation in step 1 satisfy n≥3.

3. The accurate estimation method for inertial navigation oscillation error based on multi-inertial navigation mutual observation according to claim 1, Characterized in that: The obvious change described in Step 2 is that all and j ≠ m 1 terms are increased or decreased by a value simultaneously, then it is determined that the amplitude of the Earth period oscillation error term of the inertial navigation has changed.

4. The accurate estimation method for inertial navigation oscillation error based on multi-inertial navigation mutual observation according to claim 1, Characterized in that: The inertial navigation calculation described in Step 2 Phase of the latitude Earth period oscillation error term comprises the following steps: 1) Observation t 1 Inertial navigation G before and after the moment i , where i = 1, 2, … n and i ≠ m 1 Corresponding to A i,j , select the corresponding A according to the change of j = 1, 2, … n and j ≠ i i,j The inertial navigation G with the smallest change s , determine the inertial navigation G s The oscillation error has not changed, extract t 1 Inertial navigation G before the moment t s and Amplitude of the earth periodic oscillation term in the latitude difference information Phase t 1 Inertial navigation G at the moment t s and Amplitude of the earth periodic oscillation term in the latitude difference information Phase 2) Calculation of inertial navigation Phase of the earth periodic oscillation error term arctan is the arctangent function.

5. The accurate estimation method for inertial navigation oscillation error based on multi-inertial navigation mutual observation according to claim 1, Characterized in that: The inertial navigation calculation described in Step 4 Amplitude of the latitude earth periodic oscillation error term and the inertial navigation Amplitude of the latitude earth periodic oscillation error term comprises the following steps: 1) According to t 2 inertial navigation at moment and latitude difference information extract amplitude of the medium-earth period oscillation term and phase 2) Calculate inertial navigation Amplitude of the earth periodic oscillation error term 3) Calculate inertial navigation Amplitude of the Earth's periodic oscillation error term 6. The accurate estimation method for inertial navigation oscillation error based on multi-inertial navigation mutual observation according to claim 1, Characterized in that: The inertial navigation G calculated in step 5 i , where i = 1, 2, … n, and i ≠ m 1 , i ≠ m 2 The amplitude A of the latitude earth periodic oscillation error term i and the phase The method is as follows:

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