Alignment method for self-correction parameters of three self-laser inertial measurement units
By rotating the inertia group in the three-self laser inertia group and performing rapid self-calibration, accelerometer errors are obtained and compensated, the problem of degradation of strike accuracy caused by accelerometer errors is solved, and high-precision alignment is achieved in a short time.
Patent Information
- Application Number
- CN202411693892.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-11-25
- Publication Date
- 2025-03-28
AI Technical Summary
Under the long-term storage conditions of weapon systems, the accelerometer scaling factor and the accelerometer zero-bias parameter produce drift errors over time, resulting in a decrease in strike accuracy. The existing self-calibration method is long and cannot meet the needs of rapid response.
By rotating the inertia group to six positions, coarse alignment calculation is performed using acceleration data and angular velocity data, and then fast self-calibration calculation is performed in a standstill state, obtaining the accelerometer zero deviation error and scale factor error, and compensating during the alignment process to improve alignment accuracy.
The alignment accuracy is significantly improved within the same alignment time, ensuring the strike accuracy of the weapon system, and meeting the needs of rapid response.
Smart Images
Figure CN119714349A_ABST
Abstract
Description
Technical Field
[0001] The invention relates to an alignment method of self-correction parameters and belongs to the technical field of inertial navigation. Background Art
[0002] The three-autonomous laser inertial group uses three orthogonally distributed accelerometers and three orthogonally distributed gyroscopes to measure the acceleration increments and angular velocity increments of the three axes of the spatial coordinate system, thereby helping the weapon system to locate, orient, and track and navigate. Given that under the long-term storage conditions of the weapon system, the accelerometer scale factor and the accelerometer zero bias parameters will produce a certain drift error over time, making it difficult to ensure the strike accuracy of the weapon system during the parameter retention period. Self-calibration can be achieved through the inner frame and outer frame of the three-autonomous laser inertial group, but the time generally exceeds 40 minutes, which cannot meet the actual use requirements of rapid response. Therefore, it is urgent to provide a new alignment method to improve the alignment accuracy under a certain alignment time (5 minutes), thereby effectively solving the above problems. Summary of the invention
[0003] The present invention aims to provide an alignment method for a three-self laser inertial group self-correcting parameter, which can obtain a higher-precision alignment result within the same alignment time by compensating for the inertial device error, thereby ensuring the strike accuracy of the weapon system.
[0004] In order to achieve the above object, the technical solution adopted by the present invention is: a method for aligning the self-correction parameters of a three-laser inertial group, the method comprising:
[0005] Step 1: Rotate the inertia group so that it is located in six positions in sequence:
[0006] When the inertial group rotates to a first preset time, the acceleration data and angular velocity data output by the inertial group within the first preset time are used to complete the coarse alignment calculation to obtain the coarse alignment attitude angle of the inertial group, including the coarse alignment pitch angle, the coarse alignment azimuth angle and the coarse alignment roll angle;
[0007] When the inertial group rotates to the sixth position and stops, a fast self-calibration calculation is completed within a second preset time to obtain the accelerometer zero bias error and scale factor error of the three axes of the inertial group;
[0008] Step 2: During the alignment process, the accelerometer zero bias error and scale factor error of the three axes of the inertial group obtained through fast self-calibration are used to compensate the acceleration data of the three axes:
[0009] According to the rough alignment azimuth obtained in step 1, rotate the inertia group so that it is located in two alignment positions in sequence and then return to the zero position and lock it;
[0010] The alignment calculation is completed within a third preset time, and the alignment attitude angles of the inertial group, namely, the alignment pitch angle, the alignment azimuth angle and the alignment roll angle, are output.
[0011] Inertial devices have the inherent property that parameter errors drift over time, which can be corrected through self-calibration, but the self-calibration time is long. When users need to respond quickly, there is no time to do self-calibration, and they can only rely on the accuracy of the inertial device itself. The technical solution provided by the present invention can realize the calibration and use of the accelerometer scale factor error and the accelerometer zero bias error, breaking through the restriction of the inertial device accuracy on the alignment accuracy.
[0012] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization:
[0013] In one preferred embodiment, in step 1, the acceleration data and angular velocity data output by the inertial group within the first preset time are used to complete the coarse alignment calculation to obtain the coarse alignment attitude angle of the inertial group, specifically including:
[0014] Construct the matrix C of this system b0 =[G 0 WG 0 ×W] T ;
[0015] Among them, G 0 =[f x0 f y0 f z0 ] T , W = [ω x ω y ω z ] T , f x0 is the X-axis acceleration data, f y0 is the Y-axis acceleration data, f z0 is the Z-axis acceleration data, ω x is the X-axis angular velocity data, ω y is the Y-axis angular velocity data, ω z is the Z-axis angular velocity data;
[0016] Constructing the inertial system matrix
[0017] Where g is the local gravitational acceleration, ω ie is the angular velocity of the earth's rotation, L is the latitude;
[0018] Get the coarse alignment pose matrix
[0019] Among them, C b0 -1 C b0 The inverse matrix of
[0020] Calculate the rough alignment attitude angle of the inertial group. The specific calculation formula is as follows:
[0021] θ 0 =arcsin(C 23 )
[0022] ψ 0 = -arctan(C 21 / C 22 )
[0023] γ 0 = -arctan(C 13 / C 33 )
[0024] Among them, θ 0 is the coarse alignment pitch angle, ψ 0 is the coarse alignment azimuth, γ 0 is the coarse alignment roll angle, C 23 for The data in the 2nd row and 3rd column of the matrix, C 21 for The data in the 2nd row and 1st column of the matrix, C 22 for The data in the 2nd row and 2nd column of the matrix, C 13 for The data in the first row and third column of the matrix, C 33 for The data in the 3rd row and 3rd column of the matrix;
[0025] Preferably, the first preset time is 18s.
[0026] In one preferred embodiment, in step 1, completing the rapid self-calibration calculation within the second preset time specifically includes:
[0027] Calculate the speed error of the 6-position navigation solution. The specific calculation formula is as follows:
[0028]
[0029] Where j = 1, 2, 3, 4, 5, 6, is the velocity error at the jth position at time k, is the velocity error at the jth position at time k-1, is the Z-axis velocity error at the jth position at time k-1,
[0030] is the Y-axis velocity error at the jth position at time k-1, is the X-axis velocity error at the jth position at time k-1, is the rough alignment posture matrix at time k, is the rough alignment posture matrix at time k-1, Δt is the sampling period;
[0031] The three-axis components of the six positions in the inertial system are obtained. The specific calculation formula is as follows:
[0032]
[0033]
[0034]
[0035] in, is the X-axis component of the j-th position in the inertial system, is the Y-axis component of the j-th position in the inertial system, is the Z-axis component of the j-th position in the inertial system, is the static data length of the jth position, is the output of the X-axis acceleration at the jth position at time k, is the output of the Y-axis acceleration at the jth position at time k, is the output of the Z-axis acceleration at the jth position at time k;
[0036] Preferably, the second preset time is 79 seconds.
[0037] In one preferred embodiment, in step 1, the accelerometer zero bias error and scale factor error of the three axes of the inertial group are obtained, and the specific calculation formula is as follows:
[0038]
[0039]
[0040]
[0041]
[0042]
[0043]
[0044] Among them, δK 0x is the X-axis accelerometer bias error, δK 1x is the X-axis accelerometer scale factor error, δK 0y is the Y-axis accelerometer bias error, δK 1y is the Y-axis accelerometer scale factor error, δK 0z is the Z-axis accelerometer bias error, δK 1z is the Z-axis accelerometer scale factor error.
[0045] In one preferred embodiment, in step 2, during the alignment process, the accelerometer zero bias error and scale factor error of the three axes of the inertial group obtained by fast self-calibration are used to compensate the acceleration data of the three axes. The specific calculation formula is as follows:
[0046] f x =N ax / (K 1x +δK 1x )-(K 0x +δK 0x )
[0047] f y =N ay / (K 1y +δK 1y )-(K 0y +δK 0y )
[0048] f z =N az / (K 1z +δK 1z )-(K 0z +δK 0z )
[0049] Among them, N ax is the original pulse output by the X-axis accelerometer, N ay is the original pulse output by the Y-axis accelerometer, N az is the original pulse output by the Z-axis accelerometer, K 1x is the X-axis acceleration scale factor, K 0x is the X-axis acceleration zero bias, K 1y is the Y-axis acceleration scale factor, K 0y is the Y-axis acceleration zero bias, K 1z is the Z-axis acceleration scale factor, K 0z is the Z-axis acceleration zero bias, f x To compensate the X-axis acceleration data, f y To compensate the Y-axis acceleration data, f z To compensate the Z-axis acceleration data, δK 0x is the X-axis accelerometer bias error, δK 1x is the X-axis accelerometer scale factor error, δK 0y is the Y-axis accelerometer bias error, δK 1y is the Y-axis accelerometer scale factor error, δK 0z is the Z-axis accelerometer bias error, δK 1z is the Z-axis accelerometer scale factor error.
[0050] In one preferred embodiment, in step 2, completing the alignment calculation within a third preset time and outputting the alignment attitude angle of the inertial group, namely, the alignment pitch angle, the alignment azimuth angle and the alignment roll angle, specifically includes:
[0051] Construct the matrix C of this system b =[GWG×W] T ;
[0052] Where G = [f x f y f z ] T , W = [ω x ω y ω z ] T ,ω x is the X-axis angular velocity data, ω y is the Y-axis angular velocity data, ω z is the Z-axis angular velocity data;
[0053] Constructing the inertial system matrix
[0054] Where g is the local gravitational acceleration, ω ie is the angular velocity of the earth's rotation, L is the latitude;
[0055] Get the alignment attitude matrix
[0056] Among them, C b -1 C b The inverse matrix of
[0057] Output the alignment attitude angle of the inertial group. The specific calculation formula is as follows:
[0058] θ=arcsin(C 23 )
[0059] ψ=-arctan(C 21 / C 22 )
[0060] γ=-arctan(C 13 / C 33 )
[0061] Among them, θ is the pitch angle, ψ is the azimuth angle, γ is the roll angle, C 23 for The data in the 2nd row and 3rd column of the matrix, C 21 for The data in the 2nd row and 1st column of the matrix, C 22 for The data in the 2nd row and 2nd column of the matrix, C13 for The data in the first row and third column of the matrix, C 33 for The data in the 3rd row and 3rd column of the matrix;
[0062] Preferably, the third preset time is 290s.
[0063] In one of the preferred embodiments, in step 1, the second position is obtained by rotating 180° forward around the Z axis from the first position, the third position is obtained by rotating 90° forward around the Z axis and then reversely rotating 90° around the Y axis from the second position, the fourth position is obtained by reversely rotating 180° around the X axis from the third position, the fifth position is obtained by reversely rotating 90° around the Y axis from the fourth position, and the sixth position is obtained by rotating 90° forward around the Y axis from the fifth position, that is, the six positions of the inertial group in sequence.
[0064] In one of the preferred embodiments, in step 2, according to the rough alignment azimuth obtained in step 1, the alignment is performed by rotating around the Y axis by an angle greater than 90° to due east or due west to obtain the first alignment position, and then rotating around the Y axis by 180° from the first alignment position to obtain the second alignment position.
[0065] Compared with the prior art, the beneficial effects of the present invention are as follows: the present invention provides an alignment method for self-correcting parameters of a three-autonomous laser inertial group, which quickly compensates and corrects the errors of the accelerometer scale factor and the accelerometer zero bias parameter generated during long-term storage, so as to achieve the purpose that the accelerometer scale factor and the accelerometer zero bias parameter can be marked and used immediately, breaking through the restriction of the inertial device accuracy on the alignment accuracy, obtaining a higher-precision alignment result within the same alignment time, and ensuring the strike accuracy of the weapon system. BRIEF DESCRIPTION OF THE DRAWINGS
[0066] Figure 1 It is a flow chart of a method for aligning the self-correction parameters of a three-laser inertial group according to an embodiment of the present invention. DETAILED DESCRIPTION
[0067] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.
[0068] Example 1
[0069] This embodiment 1 provides a method for aligning parameters of a three-axis laser inertial system self-calibration system, comprising the following steps:
[0070] Step 1: Rotate the inertia group so that it is located in six positions in sequence:
[0071] When the inertial group rotates to a first preset time, the acceleration data and angular velocity data output by the inertial group within the first preset time are used to complete the coarse alignment calculation to obtain the coarse alignment attitude angle of the inertial group, including the coarse alignment pitch angle, the coarse alignment azimuth angle and the coarse alignment roll angle;
[0072] When the inertial group rotates to the sixth position and stops, a fast self-calibration calculation is completed within a second preset time to obtain the accelerometer zero bias error and scale factor error of the three axes of the inertial group;
[0073] Step 2: During the alignment process, the accelerometer zero bias error and scale factor error of the three axes of the inertial group obtained through fast self-calibration are used to compensate the acceleration data of the three axes:
[0074] According to the rough alignment azimuth obtained in step 1, rotate the inertia group so that it is located in two alignment positions in sequence and then return to the zero position and lock it;
[0075] The alignment calculation is completed within a third preset time, and the alignment attitude angles of the inertial group, namely, the alignment pitch angle, the alignment azimuth angle and the alignment roll angle, are output.
[0076] Inertial devices have the inherent property that parameter errors drift over time, which can be corrected through self-calibration, but the self-calibration time is long. When users need to respond quickly, there is no time to do self-calibration, and they can only rely on the accuracy of the inertial device itself. The technical solution provided by the present invention can realize the calibration and use of the accelerometer scale factor error and the accelerometer zero bias error, breaking through the restriction of the inertial device accuracy on the alignment accuracy.
[0077] Furthermore, in step 1, the acceleration data and angular velocity data output by the inertial group within the first preset time are used to complete the coarse alignment calculation to obtain the coarse alignment attitude angle of the inertial group, which specifically includes:
[0078] Construct the matrix C of this system b0 =[G 0 WG 0 ×W] T ;
[0079] Among them, G 0 =[f x0 f y0 f z0 ] T , W = [ω x ω y ω z ] T , f x0 is the X-axis acceleration data, f y0 is the Y-axis acceleration data, f z0 is the Z-axis acceleration data, ω x is the X-axis angular velocity data, ω yis the Y-axis angular velocity data, ω z is the Z-axis angular velocity data;
[0080] Constructing the inertial system matrix
[0081] Where g is the local gravitational acceleration, ω ie is the angular velocity of the earth's rotation, L is the latitude;
[0082] Get the coarse alignment pose matrix
[0083] Among them, C b0 -1 C b0 The inverse matrix of
[0084] Calculate the rough alignment attitude angle of the inertial group. The specific calculation formula is as follows:
[0085] θ 0 =arcsin(C 23 )
[0086] ψ 0 = -arctan(C 21 / C 22 )
[0087] γ 0 = -arctan(C 13 / C 33 )
[0088] Among them, θ 0 is the coarse alignment pitch angle, ψ 0 is the coarse alignment azimuth, γ 0 is the coarse alignment roll angle, C 23 for The data in the 2nd row and 3rd column of the matrix, C 21 for The data in the 2nd row and 1st column of the matrix, C 22 for The data in the 2nd row and 2nd column of the matrix, C 13 for The data in the first row and third column of the matrix, C 33 for The data in the 3rd row and 3rd column of the matrix;
[0089] Preferably, the first preset time is 18s.
[0090] Furthermore, in step 1, completing the rapid self-calibration calculation within the second preset time specifically includes:
[0091] Calculate the speed error of the 6-position navigation solution. The specific calculation formula is as follows:
[0092]
[0093] Where j = 1, 2, 3, 4, 5, 6, is the velocity error at the jth position at time k, is the velocity error at the jth position at time k-1, is the Z-axis velocity error at the jth position at time k-1,
[0094] is the Y-axis velocity error at the jth position at time k-1, is the X-axis velocity error at the jth position at time k-1, is the rough alignment posture matrix at time k, is the rough alignment posture matrix at time k-1, Δt is the sampling period;
[0095] The three-axis components of the six positions in the inertial system are obtained. The specific calculation formula is as follows:
[0096]
[0097]
[0098]
[0099] in, is the X-axis component of the j-th position in the inertial system, is the Y-axis component of the j-th position in the inertial system, is the Z-axis component of the j-th position in the inertial system, is the static data length of the jth position, is the output of the X-axis acceleration at the jth position at time k, is the output of the Y-axis acceleration at the jth position at time k, is the output of the Z-axis acceleration at the jth position at time k;
[0100] Preferably, the second preset time is 79 seconds.
[0101] Furthermore, in step 1, the accelerometer zero bias error and scale factor error of the three axes of the inertial group are obtained, and the specific calculation formula is as follows:
[0102]
[0103]
[0104]
[0105]
[0106]
[0107]
[0108] Among them, δK 0x is the X-axis accelerometer bias error, δK 1x is the X-axis accelerometer scale factor error, δK 0y is the Y-axis accelerometer bias error, δK 1y is the Y-axis accelerometer scale factor error, δK 0z is the Z-axis accelerometer bias error, δK 1z is the Z-axis accelerometer scale factor error.
[0109] Furthermore, in step 2, during the alignment process, the accelerometer zero bias error and scale factor error of the three axes of the inertial group obtained by fast self-calibration are used to compensate the acceleration data of the three axes. The specific calculation formula is as follows:
[0110] f x =N ax / (K 1x +δK 1x )-(K 0x +δK 0x )
[0111] f y =N ay / (K 1y +δK 1y )-(K 0y +δK 0y )
[0112] f z =N az / (K 1z +δK 1z )-(K 0z +δK 0z )
[0113] Among them, N ax is the original pulse output by the X-axis accelerometer, N ay is the original pulse output by the Y-axis accelerometer, N az is the original pulse output by the Z-axis accelerometer, K 1x is the X-axis acceleration scale factor, K 0x is the X-axis acceleration zero bias, K 1y is the Y-axis acceleration scale factor, K 0y is the Y-axis acceleration zero bias, K 1z is the Z-axis acceleration scale factor, K 0z is the Z-axis acceleration zero bias, fx To compensate the X-axis acceleration data, f y To compensate the Y-axis acceleration data, f z To compensate the Z-axis acceleration data, δK 0x is the X-axis accelerometer bias error, δK 1x is the X-axis accelerometer scale factor error, δK 0y is the Y-axis accelerometer bias error, δK 1y is the Y-axis accelerometer scale factor error, δK 0z is the Z-axis accelerometer bias error, δK 1z is the Z-axis accelerometer scale factor error.
[0114] Furthermore, in step 2, the alignment calculation is completed within a third preset time, and the alignment attitude angle of the inertial group, namely, the alignment pitch angle, the alignment azimuth angle and the alignment roll angle, is output, which specifically includes:
[0115] Construct the matrix C of this system b =[GWG×W] T ;
[0116] Where G = [f x f y f z ] T , W = [ω x ω y ω z ] T ,ω x is the X-axis angular velocity data, ω y is the Y-axis angular velocity data, ω z is the Z-axis angular velocity data;
[0117] Constructing the inertial system matrix
[0118] Where g is the local gravitational acceleration, ω ie is the angular velocity of the earth's rotation, L is the latitude;
[0119] Get the alignment attitude matrix
[0120] Among them, C b -1 C b The inverse matrix of
[0121] Output the alignment attitude angle of the inertial group. The specific calculation formula is as follows:
[0122] θ=arcsin(C 23 )
[0123] ψ=-arctan(C 21 / C22 )
[0124] γ=-arctan(C 13 / C 33 )
[0125] Among them, θ is the pitch angle, ψ is the azimuth angle, γ is the roll angle, C 23 for The data in the 2nd row and 3rd column of the matrix, C 21 for The data in the 2nd row and 1st column of the matrix, C 22 for The data in the 2nd row and 2nd column of the matrix, C 13 for The data in the first row and third column of the matrix, C 33 for The data in the 3rd row and 3rd column of the matrix;
[0126] Preferably, the third preset time is 290s.
[0127] Furthermore, in step 1, the second position is obtained by rotating 180° forward around the Z axis from the first position, the third position is obtained by rotating 90° forward around the Z axis and then reversing 90° around the Y axis from the second position, the fourth position is obtained by reversing 180° around the X axis from the third position, the fifth position is obtained by reversing 90° around the Y axis from the fourth position, and the sixth position is obtained by rotating 90° forward around the Y axis from the fifth position, that is, the six positions of the inertial group in sequence.
[0128] Further, in step 2, according to the rough alignment azimuth obtained in step 1, the alignment is obtained by rotating around the Y axis by an angle greater than 90° to due east or due west to obtain the first alignment position, and then rotating around the Y axis by 180° from the first alignment position to obtain the second alignment position.
[0129] Example 2
[0130] This embodiment 2 provides a method for aligning three laser inertial group self-calibration parameters, and its flow chart is as follows: Figure 1 As shown, the following steps are included:
[0131] Step 1: Rapid self-calibration and coarse alignment
[0132] The operation of fast self-calibration inertial group rotation is as follows. The time and speed used in the operation are engineering experience values to ensure that the alignment is completed within 5 minutes:
[0133] The first position remains still for a total of 5 seconds;
[0134] The outer frame rotates 180° around the Z axis at 125° / s and stops after the rotation is completed. The total time is 8.805s.
[0135] The outer frame rotates 90° around the Z axis at 125° / s, and the inner frame rotates 90° around the Y axis at 125° / s. After the rotation is completed, it stops, which takes a total of 8 seconds. At the same time, the acceleration data and angular velocity data output by the 0-18s inertial group are used to complete the rough alignment calculation.
[0136] The outer frame rotates 180° around the X-axis at 125° / s and stops after the rotation is completed. The total time is 8s.
[0137] The inner frame rotates 90° around the Y axis at 125° / s and stops after the rotation is completed. The total time is 8s.
[0138] The inner frame rotates 90° around the Y axis at 125° / s and stops after the rotation is completed. It takes a total of 8 seconds.
[0139] Complete the fast self-calibration calculation and update it to the calibration parameters before 79 seconds;
[0140] Coarse alignment is to calculate the attitude matrix of the current position of the inertial group, so as to calculate the attitude angle, including pitch angle, azimuth angle and roll angle. The specific algorithm is as follows:
[0141] Construct the matrix of this system:
[0142] Using the acceleration channel data f of the three orthogonal axes of the inertial group x0 , f y0 , f z0 , construct the vector
[0143] G 0 =[f x0 f y0 f z0 ] T ,
[0144] Using the angular velocity channel data ω of the three orthogonal axes of the inertial group x ,ω y ,ω z , construct the vector
[0145] W=[ω x ω y ω z ] T ,
[0146] The above two vectors and their cross product result construct the matrix C of this system b0 =[G 0 WG 0 ×W] T , based on the local gravitational acceleration g and the Earth's rotation angular velocity ω ie And latitude L to construct the inertial system matrix
[0147]
[0148] Get the coarse alignment posture transformation matrix, that is, the coarse alignment posture matrix
[0149]
[0150] Among them, C b0 -1 C b0 The inverse matrix of 0 is the coarse alignment pitch angle, ψ 0 is the coarse alignment azimuth, γ 0 is the coarse alignment roll angle;
[0151] The rough alignment result is calculated by formula (1) to obtain the current attitude of the three-inertial group. The specific calculation formula is as follows:
[0152] θ 0 =arcsin(C 23 )
[0153] ψ 0 = -arctan(C 21 / C 22 )
[0154] γ 0 = -arctan(C 13 / C 33 )
[0155] Among them, C 23 for The data in the 2nd row and 3rd column of the matrix, C 21 for The data in the 2nd row and 1st column of the matrix, C 22 for The data in the 2nd row and 2nd column of the matrix, C 13 for The data in the first row and third column of the matrix, C 33 for The data in the 3rd row and 3rd column of the matrix.
[0156] Fast self-calibration is calculated by the speed error solved by 6 position navigation. The specific calculation formula is as follows:
[0157]
[0158] Where j = 1, 2, 3, 4, 5, 6, is the velocity error at the jth position at time k,
[0159] is the velocity error at the jth position at time k-1, is the Z-axis velocity error at the jth position at time k-1, is the Y-axis velocity error at the jth position at time k-1, is the X-axis velocity error at the jth position at time k-1, is the rough alignment posture matrix at time k, is the rough alignment posture matrix at time k-1, Δt is the sampling period;
[0160] The components of the uncompensated accelerometer parameter errors in the inertial system at the six positions are calculated by formula (2). The specific calculation formula is as follows:
[0161]
[0162]
[0163]
[0164] in, is the X-axis component of the uncompensated accelerometer parameter error at the jth position in the inertial system, is the Y-axis component of the uncompensated accelerometer parameter error at the jth position in the inertial system, is the Z-axis component of the uncompensated accelerometer parameter error at the jth position in the inertial system, is the static data length of the jth position, is the X-axis acceleration output at the j-th position k, is the Y-axis acceleration output at the j-th position at time k, is the Z-axis acceleration output at the j-th position at time k;
[0165] According to the uncompensated accelerometer parameter error component in the inertial system obtained by rapid self-calibration, the accelerometer zero bias error δK of the three axes is calculated. 0x ,δK 0y ,δK 0z and the scale factor error δK 1x ,δK 1y ,δK 1z :
[0166]
[0167]
[0168]
[0169]
[0170]
[0171]
[0172] Step 2: Align
[0173] According to the rough alignment azimuth angle obtained in step 1, the outer frame can be controlled to rotate around the Y axis at 125° / s to an angle greater than 90° to the east or west position and then stop, which takes a total of 97 seconds;
[0174] The outer frame rotates 180° around the Y axis at 125° / s and stops after the rotation is completed. The total time is 97s.
[0175] The inner and outer frames return to zero position at 125° / s and are locked. During the alignment process, the accelerometer scale factor error and accelerometer zero bias error obtained by rapid self-calibration are used to compensate the accelerometer data. The specific calculation formula is as follows:
[0176] f x =N ax / (K 1x +δK 1x )-(K 0x +δK 0x )
[0177] f y =N ay / (K 1y +δK 1y )-(K 0y +δK 0y )
[0178] f z =N az / (K 1z +δK 1z )-(K 0z +δK 0z )
[0179] Among them, N ax is the original pulse output by the X-axis accelerometer, N ay is the original pulse output by the Y-axis accelerometer, N az K is the original pulse output by the Z-axis accelerometer. 1x is the X-axis acceleration scale factor, K 0x is the X-axis acceleration zero bias, K 1y is the Y-axis acceleration scale factor, K 0y is the Y-axis acceleration zero bias, K 1z is the Z-axis acceleration scale factor, K 0z is the Z-axis acceleration zero bias, f x To compensate the X-axis acceleration data, f y To compensate the Y-axis acceleration data, f z To compensate the Z-axis acceleration data, δK0x is the X-axis accelerometer bias error, δK 1x is the X-axis accelerometer scale factor error, δK 0y is the Y-axis accelerometer bias error, δK 1y is the Y-axis accelerometer scale factor error, δK 0z is the Z-axis accelerometer bias error, δK 1z is the Z-axis accelerometer scale factor error.
[0180] The alignment calculation is completed before 290 seconds, and the three aligned attitude angles are output, including:
[0181] Get the alignment pose matrix:
[0182]
[0183] Among them, C b -1 C b The inverse matrix of this system is C b =[GWG×W] T , G=[f x f y f z ] T , W = [ω x ω y ω z ] T ,ω x is the X-axis angular velocity data, ω y is the Y-axis angular velocity data, ω z is the Z-axis angular velocity data;
[0184] The alignment attitude angle of the inertial group is calculated according to formula (3). The specific calculation formula is as follows:
[0185] θ=arcsin(C 23 )
[0186] ψ=-arctan(C 21 / C 22 )
[0187] γ=-arctan(C 13 / C 33 )
[0188] Among them, θ is the pitch angle, ψ is the azimuth angle, γ is the roll angle, C 23 for The data in the 2nd row and 3rd column of the matrix, C 21 for The data in the 2nd row and 1st column of the matrix, C 22 for The data in the 2nd row and 2nd column of the matrix, C 13 for The data in the first row and third column of the matrix, C 33 for The data in the 3rd row and 3rd column of the matrix.
[0189] The alignment method of the three-inertial group self-correction parameters provided in this embodiment 2 is based on the optimization of the existing 5-minute two-position alignment method. Through the self-correction parameters, the inertial device error is compensated to ensure that the alignment accuracy is improved within the same 5-minute time, thereby achieving higher alignment accuracy within the same alignment time.
[0190] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.
Claims
1. A method for aligning the self-correction parameters of a three-axis laser inertial system, characterized in that: The method comprises: Step 1: Rotate the inertia group so that it is located in six positions in sequence: When the inertial group rotates to a first preset time, the acceleration data and angular velocity data output by the inertial group within the first preset time are used to complete the coarse alignment calculation to obtain the coarse alignment attitude angle of the inertial group, including the coarse alignment pitch angle, the coarse alignment azimuth angle and the coarse alignment roll angle; When the inertial group rotates to the sixth position and stops, a fast self-calibration calculation is completed within a second preset time to obtain the accelerometer zero bias error and scale factor error of the three axes of the inertial group; Step 2: During the alignment process, the accelerometer zero bias error and scale factor error of the three axes of the inertial group obtained through fast self-calibration are used to compensate the acceleration data of the three axes: According to the rough alignment azimuth obtained in step 1, rotate the inertia group so that it is located in two alignment positions in sequence and then return to the zero position and lock it; The alignment calculation is completed within a third preset time, and the alignment attitude angles of the inertial group, namely, the alignment pitch angle, the alignment azimuth angle and the alignment roll angle, are output.
2. The method for aligning the self-correction parameters of a three-axis laser inertial system according to claim 1, characterized in that: In the step 1, the acceleration data and angular velocity data output by the inertial group within the first preset time are used to complete the coarse alignment calculation to obtain the coarse alignment attitude angle of the inertial group, which specifically includes: Construct the matrix C of this system b0 =[G0 W G0×W] T ; Where G0 = [f x0 f y0 f z0 ] T , W = [ω x ω y ω z ] T , f x0 is the X-axis acceleration data, f y0 is the Y-axis acceleration data, f z0 is the Z-axis acceleration data, ω x is the X-axis angular velocity data, ω y is the Y-axis angular velocity data, ω z is the Z-axis angular velocity data; Constructing the inertial system matrix Where g is the local gravitational acceleration, ω ie is the angular velocity of the earth's rotation, L is the latitude; Get the coarse alignment pose matrix Among them, C b0 -1 C b0 The inverse matrix of Calculate the rough alignment attitude angle of the inertial group. The specific calculation formula is as follows: θ0=arcsin(C 23 ) ψ0=-arctan(C 21 / C 22 ) γ0=-arctan(C 13 / C 33 ) Where θ0 is the coarse alignment pitch angle, ψ0 is the coarse alignment azimuth angle, γ0 is the coarse alignment roll angle, C 23 for The data in the 2nd row and 3rd column of the matrix, C 21 for The data in the 2nd row and 1st column of the matrix, C 22 for The data in the 2nd row and 2nd column of the matrix, C 13 for The data in the first row and third column of the matrix, C 33 for The data in the 3rd row and 3rd column of the matrix; Preferably, the first preset time is 18s.
3. The method for aligning the self-correction parameters of a three-axis laser inertial system according to claim 2, characterized in that: In step 1, completing the rapid self-calibration calculation within the second preset time specifically includes: Calculate the speed error of the 6-position navigation solution. The specific calculation formula is as follows: Where j = 1, 2, 3, 4, 5, 6, is the velocity error at the jth position at time k, is the velocity error at the jth position at time k-1, is the Z-axis velocity error at the jth position at time k-1, is the Y-axis velocity error at the jth position at time k-1, is the X-axis velocity error at the jth position at time k-1, is the rough alignment posture matrix at time k, is the rough alignment posture matrix at time k-1, Δt is the sampling period; The three-axis components of the uncompensated accelerometer parameter errors in the inertial system are obtained at six locations. The specific calculation formula is as follows: in, is the X-axis component of the uncompensated accelerometer parameter error at the jth position in the inertial system, is the Y-axis component of the uncompensated accelerometer parameter error at the jth position in the inertial system, is the Z-axis component of the uncompensated accelerometer parameter error at the jth position in the inertial system, is the static data length of the jth position, is the X-axis acceleration output at the j-th position k, is the Y-axis acceleration output at the j-th position at time k, is the Z-axis acceleration output at the j-th position at time k; Preferably, the second preset time is 79 seconds.
4. The method for aligning the self-correction parameters of a three-axis laser inertial system according to claim 3, characterized in that: In step 1, the accelerometer zero bias error and scale factor error of the three axes of the inertial group are obtained, and the specific calculation formula is as follows: Among them, δK 0x is the X-axis accelerometer bias error, δK 1x is the X-axis accelerometer scale factor error, δK 0y is the Y-axis accelerometer bias error, δK 1y is the Y-axis accelerometer scale factor error, δK 0z is the Z-axis accelerometer bias error, δK 1z is the Z-axis accelerometer scale factor error.
5. The method for aligning the self-correction parameters of a three-axis laser inertial system according to claim 1, characterized in that: In step 2, during the alignment process, the accelerometer zero bias error and scale factor error of the three axes of the inertial group obtained by fast self-calibration are used to compensate the acceleration data of the three axes. The specific calculation formula is as follows: f x =N ax / (K 1x +δK 1x )-(K 0x +δK 0x ) f y =N ay / (K 1y +δK 1y )-(K 0y +δK 0y ) f z =N az / (K 1z +δK 1z )-(K 0z +δK 0z ) Among them, N ax is the original pulse output by the X-axis accelerometer, N ay is the original pulse output by the Y-axis accelerometer, N az is the original pulse output by the Z-axis accelerometer, K 1x is the X-axis acceleration scale factor, K 0x is the X-axis acceleration zero bias, K 1y is the Y-axis acceleration scale factor, K 0y is the Y-axis acceleration zero bias, K 1z is the Z-axis acceleration scale factor, K 0z is the Z-axis acceleration zero bias, f x To compensate the X-axis acceleration data, f y To compensate the Y-axis acceleration data, f z To compensate the Z-axis acceleration data, δK 0x is the X-axis accelerometer bias error, δK 1x is the X-axis accelerometer scale factor error, δK 0y is the Y-axis accelerometer bias error, δK 1y is the Y-axis accelerometer scale factor error, δK 0z is the Z-axis accelerometer bias error, δK 1z is the Z-axis accelerometer scale factor error.
6. The method for aligning the self-correction parameters of a three-axis laser inertial system according to claim 5, characterized in that: In step 2, the alignment calculation is completed within the third preset time, and the alignment attitude angle of the inertial group, namely, the alignment pitch angle, the alignment azimuth angle and the alignment roll angle, is output, which specifically includes: Construct the matrix C of this system b =[GWG×W] T ; Where G = [f x f y f z ] T , W = [ω x ω y ω z ] T ,ω x is the X-axis angular velocity data, ω y is the Y-axis angular velocity data, ω z is the Z-axis angular velocity data; Constructing the inertial system matrix Where g is the local gravitational acceleration, ω ie is the angular velocity of the earth's rotation, L is the latitude; Get the alignment attitude matrix Among them, C b -1 C b The inverse matrix of Output the alignment attitude angle of the inertial group. The specific calculation formula is as follows: θ=arcsin(C 23 ) ψ=-arctan(C 21 / C 22 ) γ=-arctan(C 13 / C 33 ) Among them, θ is the pitch angle, ψ is the azimuth angle, γ is the roll angle, C 23 for The data in the 2nd row and 3rd column of the matrix, C 21 for The data in the 2nd row and 1st column of the matrix, C 22 for The data in the 2nd row and 2nd column of the matrix, C 13 for The data in the first row and third column of the matrix, C 33 for The data in the 3rd row and 3rd column of the matrix; Preferably, the third preset time is 290s.
7. The method for aligning the self-correction parameters of a three-axis laser inertial system according to claim 1, characterized in that: In step 1, the second position is obtained by rotating 180° forward around the Z axis from the first position, the third position is obtained by rotating 90° forward around the Z axis and then counterclockwise around the Y axis by 90° from the second position, the fourth position is obtained by counterclockwise rotating 180° around the X axis from the third position, the fifth position is obtained by counterclockwise rotating 90° around the Y axis from the fourth position, and the sixth position is obtained by rotating 90° forward around the Y axis from the fifth position, i.e., the six positions of the inertial group in sequence.
8. The method for aligning the self-correction parameters of a three-axis laser inertial system according to claim 1, characterized in that: In step 2, according to the rough alignment azimuth obtained in step 1, the alignment is obtained by rotating around the Y axis by an angle greater than 90° to due east or due west to obtain a first alignment position, and then rotating around the Y axis by 180° from the first alignment position to obtain a second alignment position.