Single-axis rotation inertial measurement unit self-calibration method and device based on limited rotation of special equipment

Abstract

The application provides a single-axis rotating inertial unit self-calibration method and device based on limited rotation of special equipment, and in view of the application scene of important parameter self-calibration of the single-axis rotating inertial unit without disassembly, a self-calibration scheme of the single-axis rotating inertial unit based on limited rotation of special equipment is designed, the problem of important parameter self-calibration of the single-axis rotating inertial unit without disassembly is solved, and the maintainability of the single-axis rotating inertial unit is improved. The key parameter self-calibration of the single-axis rotating inertial unit without disassembly can be realized, and the self-maintenance capability of the single-axis rotating inertial unit is improved.

Description

Technical Field

[0001] This invention relates to the field of single-axis rotating inertial navigation system (INS) self-calibration technology, and in particular to a method and apparatus for self-calibrating a single-axis rotating INS based on the limited rotation of special equipment. Background Technology

[0002] System-level calibration is a method that excites the error parameters of inertial devices by designing a reasonable rotation sequence, and then estimates the error parameters optimally by observing navigation information. It has the advantages of high calibration accuracy and strong anti-disturbance capability. Regularly executing the self-calibration program can ensure the long-term stability of the inertial group.

[0003] Rotary inertial navigation systems (INS) with dual- or tri-axis degrees of freedom can self-calibrate inertial device error parameters without the need for an external turntable, avoiding frequent disassembly and reassembly from the carrier and significantly reducing the maintenance difficulty of the INS. Compared to dual- or tri-axis rotary INS, single-axis rotary INS have many advantages such as small size, low cost, and high reliability, and are widely used in the field of low-cost INS. However, due to the lack of a rotational degree of freedom, single-axis rotary INS cannot independently complete system-level self-calibration. Summary of the Invention

[0004] The present invention aims to provide a method and apparatus for self-calibrating a single-axis rotating inertial navigation system based on the limited rotation of special equipment, which overcomes or at least partially solves the above problems.

[0005] To achieve the above objectives, the technical solution of the present invention is specifically implemented as follows:

[0006] One aspect of the present invention provides a self-calibration method for a single-axis rotating inertial navigation system based on finite rotation of special equipment, comprising:

[0007] Set up the single-axis rotary inertial navigation system and special equipment according to the preset method;

[0008] After the special equipment is leveled, the single-axis rotational inertial navigation system rotates according to a preset rotation position and performs self-calibration after each rotation.

[0009] The single-axis rotational inertial group rotates according to the preset angle θ after the special equipment rotates, and performs a self-calibration after each rotation, wherein the preset angle θ is (45°<θ≤90°).

[0010] After the special equipment returns to its position, the single-axis rotational inertial navigation system rotates according to the preset rotation position and performs self-calibration after each rotation.

[0011] The parameters of the gyroscope and the accumulator in the single-axis rotating inertial navigation system are estimated in real time using an online Kalman filter algorithm, and the calibration parameters in the navigation computer inside the single-axis rotating inertial navigation system are updated.

[0012] The step of setting up the single-axis rotational inertial navigation system and special equipment according to a preset method includes:

[0013] The coordinate system is defined as follows: the b coordinate system is defined as the body coordinate system of the inertial navigation system, and the coordinate axes are parallel to the output axes of the inertial devices after the inertial navigation system is calibrated; the n coordinate system is defined as the navigation coordinate system, which is the local horizontal East-North-Sky coordinate system.

[0014] The single-axis rotational inertial navigation system is installed on the special equipment.

[0015] The single-axis rotational inertial navigation system rotates according to a preset rotation position, and performs self-calibration after each rotation, including:

[0016] Upon power-up and receipt of the self-calibration command without disassembly, the single-axis rotating inertial navigation system (SIRS) begins self-calibration. The internal inertial device components of the SIRS undergo four-position rotation around the rotation axis: the inertial device components rotate 180° clockwise around the axial axis, remain stationary for 10 seconds, then rotate 180° clockwise again, remain stationary for 10 seconds; then rotate 180° counterclockwise, remain stationary for 10 seconds, and finally rotate 180° counterclockwise again, remain stationary for 10 seconds.

[0017] The step of estimating the parameters of the gyroscope and the accumulator in the single-axis rotating inertial navigation system in real time using an online Kalman filter algorithm, and updating the calibration parameters in the navigation computer inside the single-axis rotating inertial navigation system, includes:

[0018] A system error model is established, which includes: determining a state-space model based on the attitude error equation and the velocity error equation;

[0019] The attitude error equation includes:

[0020]

[0021] in:

[0022] φ n =[φ E φ N φ U ] T ,

[0023]

[0024]

[0025]

[0026] In the formula, φ i (i = E, N, U) represents the attitude error angle, δv i(i = E, N, U) represents the velocity error in the navigation system, L is the geodetic latitude, and ω ie The angular velocity of Earth's rotation. Let be the component of the Earth's rotational angular velocity in the navigation coordinate system. R represents the component of the angular velocity of the navigation coordinate system relative to the Earth coordinate system within the navigation system. M R is the radius of curvature of the Earth's meridian. N Let h be the radius of curvature of the Earth's geoid, h be the geodetic height, and v be the radius of curvature of the Earth's geoid. i (i = E, N, U) represents the navigation system velocity. Let δk be the attitude matrix from system b to system n. gii (i = x, y, z) represents the gyroscope scale coefficient error for each axis. Outputs for each axis gyroscope. Zero bias for each axis gyroscope;

[0027] The velocity error equation includes:

[0028]

[0029] in:

[0030] v n =[v E v N v U ] T , M va =f n ×,

[0031]

[0032] In the formula, f i b (i = x, y, z) represents the accelerometer output, δk aii (i = x, y, z) represents the calibration coefficient error of the accelerometer for each axis, δk aij (i = y, z, j = x, y, i ≠ j) represents the accelerometer installation error angle. Zero bias for accelerometers on each axis;

[0033] The state-space model includes:

[0034]

[0035] Z = HX + V (4)

[0036] in:

[0037] The state transition matrix F is

[0038]

[0039] in

[0040]

[0041]

[0042] The state vector X is taken as:

[0043] X = [φ n δv n δk A δk G ε b ▽ b ] T

[0044] in:

[0045] δk A =[δk axx δk ayx δk ayy δk azx δk azy δk azz ] T

[0046] δk G =[δk gxx δk gyy δk gzz ] T

[0047] The measurement Z is taken as

[0048] Z = [δv] E δv N δv U ] T

[0049] The observation matrix H is taken as

[0050] H = [O 3×3 I3 O 3×15 ]

[0051]

[0052] In the formula, and These are white noise for gyroscope angular velocity measurement and white noise for accelerometer specific force measurement, respectively, V v White noise for velocity measurement;

[0053] Discretize Equation (3) and Equation (4), and use Kalman filtering to estimate them. Obtain the optimal estimates of the calibration coefficient errors of the gyroscope and accelerometer and the zero bias parameter. Use the estimated data to update the calibration parameters in the internal navigation computer of the single-axis rotating inertial navigation system.

[0054] The methods also include:

[0055] The rotational speed of the single-axis rotating inertial navigation system frame is set to 12° / s;

[0056] The rotational speed of the special equipment is set to 3° / s.

[0057] Another aspect of the present invention provides a self-calibration device for a single-axis rotating inertial navigation system based on limited rotation of special equipment, comprising: a single-axis rotating inertial navigation system and special equipment arranged in a preset manner; wherein:

[0058] The single-axis rotational inertial navigation system (INS) is used to rotate the special equipment according to a preset rotation position after leveling, and to perform self-calibration after each rotation; after the special equipment rotates according to a preset angle θ, it is used to rotate the equipment according to the preset rotation position, and to perform self-calibration after each rotation, wherein the preset angle θ is (45° < θ ≤ 90°); after the special equipment returns to its original position, it is used to rotate the equipment according to the preset rotation position, and to perform self-calibration after each rotation; after estimating the parameters of the gyroscope and the accumulator in the single-axis rotational INS in real time using an online Kalman filter algorithm, the calibration parameters in the navigation computer are updated;

[0059] The special equipment is used to rotate according to the preset angle θ.

[0060] The single-axis rotary inertial navigation system and special equipment are configured according to a preset method as follows:

[0061] The coordinate system is defined as follows: the b coordinate system is defined as the body coordinate system of the inertial navigation system, and the coordinate axes are parallel to the output axes of the inertial devices after the inertial navigation system is calibrated; the n coordinate system is defined as the navigation coordinate system, which is the local horizontal East-North-Sky coordinate system.

[0062] The single-axis rotational inertial navigation system is installed on the special equipment.

[0063] The single-axis rotational inertial navigation system is rotated according to a preset rotation in the following manner, and self-calibrated after each rotation:

[0064] Upon power-up and receipt of the self-calibration command without disassembly, the single-axis rotating inertial navigation system (SIRS) begins self-calibration. The internal inertial device components of the SIRS undergo four-position rotation around the rotation axis: the inertial device components rotate 180° clockwise around the axial axis, remain stationary for 10 seconds, then rotate 180° clockwise again, remain stationary for 10 seconds; then rotate 180° counterclockwise, remain stationary for 10 seconds, and finally rotate 180° counterclockwise again, remain stationary for 10 seconds.

[0065] The device further includes an estimation unit, which estimates the parameters of the gyroscope and the accumulator in the single-axis rotating inertial navigation system in real time using an online Kalman filter algorithm, and notifies the calibration parameters in the navigation computer inside the single-axis rotating inertial navigation system to be updated:

[0066] A system error model is established, which includes: determining a state-space model based on the attitude error equation and the velocity error equation;

[0067] The attitude error equation includes:

[0068]

[0069] in:

[0070] φ n =[φ E φ N φ U ] T ,

[0071]

[0072]

[0073]

[0074] In the formula, φ i (i = E, N, U) represents the attitude error angle, δv i (i = E, N, U) represents the velocity error in the navigation system, L is the geodetic latitude, and ω ie The angular velocity of Earth's rotation. Let be the component of the Earth's rotational angular velocity in the navigation coordinate system. R represents the component of the angular velocity of the navigation coordinate system relative to the Earth coordinate system within the navigation system. M R is the radius of curvature of the Earth's meridian. N Let h be the radius of curvature of the Earth's geoid, h be the geodetic height, and v be the radius of curvature of the Earth's geoid. i (i = E, N, U) represents the navigation system velocity. Let δk be the attitude matrix from system b to system n. gii (i = x, y, z) represents the gyroscope scale coefficient error for each axis. Outputs for each axis gyroscope. Zero bias for each axis gyroscope;

[0075] The velocity error equation includes:

[0076]

[0077] in:

[0078] v n =[v E v N v U ] T , M va =f n ×,

[0079]

[0080] In the formula, f i b (i = x, y, z) represents the accelerometer output, δk aii (i = x, y, z) represents the calibration coefficient error of the accelerometers on each axis, δk aij (i = y, z, j = x, y, i ≠ j) represents the accelerometer installation error angle. Zero bias for accelerometers on each axis;

[0081] The state-space model includes:

[0082]

[0083] Z = HX + V (4)

[0084] in:

[0085] The state transition matrix F is

[0086]

[0087] in

[0088]

[0089]

[0090] The state vector X is taken as:

[0091] X = [φ n δv n δk A δk G ε b ▽ b ]T

[0092] in:

[0093] δk A =[δk axx δk ayx δk ayy δk azx δk azy δk azz ] T

[0094] δk G =[δk gxx δk gyy δk gzz ] T

[0095] The measurement Z is taken as

[0096] Z = [δv] E δv N δv U ] T

[0097] The observation matrix H is taken as

[0098] H = [O 3×3 I3 O 3×15 ]

[0099]

[0100] In the formula, and These are white noise for gyroscope angular velocity measurement and white noise for accelerometer specific force measurement, respectively, V v White noise for velocity measurement;

[0101] Discretize Equation (3) and Equation (4), and use Kalman filtering to estimate them. Obtain the optimal estimates of the calibration coefficient errors of the gyroscope and accelerometer and the zero bias parameter, and notify the calibration parameters in the internal navigation computer of the single-axis rotating inertial group to be updated.

[0102] The single-axis rotating inertial group is further configured to set the rotational speed of the single-axis rotating inertial group frame to 12° / s; the special equipment is further configured to set the rotational speed of the special equipment to 3° / s.

[0103] Therefore, the self-calibration method and apparatus for single-axis rotating inertial navigation systems (INS) based on limited rotation of special equipment provided by this invention addresses the application scenario of self-calibrating critical parameters of INS without disassembly. It designs a self-calibration scheme for INS under limited rotation conditions of special equipment, solving the problem of self-calibrating critical parameters of INS without disassembly and improving the maintainability of INS. It enables self-calibration of key parameters of INS without disassembly, enhancing the autonomous maintenance capability of INS. Attached Figure Description

[0104] To more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings used in the following description of the embodiments will be briefly introduced. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0105] Figure 1 A flowchart of a single-axis rotating inertial navigation system self-calibration method based on limited rotation of special equipment provided in an embodiment of the present invention;

[0106] Figure 2 This is a schematic diagram of the limited rotation of special equipment provided in an embodiment of the present invention;

[0107] Figure 3 This is a schematic diagram of the calibration path provided in an embodiment of the present invention;

[0108] Figure 4 This is a schematic diagram of the structure of a single-axis rotational inertial navigation system self-calibration device based on the limited rotation of special equipment, provided in an embodiment of the present invention. Detailed Implementation

[0109] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete, and will fully convey the scope of the disclosure to those skilled in the art.

[0110] Figure 1 A flowchart of a self-calibration method for a single-axis rotating inertial navigation system based on finite rotation of special equipment, provided by an embodiment of the present invention, is shown below. Figure 1 The self-calibration method for a single-axis rotating inertial navigation system based on limited rotation of special equipment provided in this embodiment of the invention includes:

[0111] S1, set the single-axis rotational inertia and special equipment according to the preset method.

[0112] As an optional implementation of this invention, see Figure 2 The setup of the single-axis rotating inertial group (IIG) and special equipment according to a preset method includes: coordinate system definition, where the b-coordinate system is defined as the IIG's body coordinate system, with its coordinate axes parallel to the output axes of the inertial devices after IIG calibration; and the n-coordinate system is defined as the navigation coordinate system, using the local horizontal East-North-Sky (ENU) coordinate system. As an optional embodiment of the present invention, the single-axis rotating IIG is mounted on the special equipment. In one optional manner, the single-axis rotating IIG is mounted on the upper surface of the special equipment.

[0113] S2, after the special equipment is leveled, the single-axis rotational inertial group rotates according to the preset rotation position and performs self-calibration after each rotation.

[0114] As an optional embodiment of the present invention, the single-axis rotating inertial group rotates according to a preset rotation position and performs self-calibration after each rotation position, including: the single-axis rotating inertial group is powered on, and after receiving the self-calibration command without disassembly, it begins self-calibration. The inertial device assembly inside the single-axis rotating inertial group rotates around the rotation axis in four positions: the inertial device assembly rotates 180° clockwise around the axial axis, rests for 10 seconds, then rotates 180° clockwise again, rests for 10 seconds; then rotates 180° counterclockwise, rests for 10 seconds, and finally rotates 180° counterclockwise, rests for 10 seconds.

[0115] S3, after the special equipment rotates at a preset angle θ, the single-axis rotation inertial group rotates according to a preset rotation position and performs self-calibration after each rotation position. The preset angle θ is 45°<θ≤90°.

[0116] Specifically, the special equipment can rotate within a certain angle to assist the single-axis rotational inertial navigation system in parameter calibration. After the special equipment rotates to its designated position, the single-axis rotational inertial navigation system performs a rotation according to a preset position and performs a self-calibration operation after each rotation.

[0117] S4, after the special equipment falls back into position, the single-axis rotation inertial group rotates according to the preset rotation position and performs self-calibration after each rotation.

[0118] Specifically, after the special equipment returns to its position, the single-axis rotation inertial navigation system performs rotation according to the preset rotation position and performs a self-calibration operation after each rotation.

[0119] S5 uses an online Kalman filter algorithm to estimate the parameters of the gyroscope and accelerator in the single-axis rotating inertial group in real time, and updates the calibration parameters in the navigation computer inside the single-axis rotating inertial group.

[0120] Specifically, a single-axis rotating inertial navigation system (INS) has only one rotational degree of freedom, making it impossible to excite all the scale coefficients of the gyroscopes and accelerometers within the INS, as well as error parameters such as zero bias. Specialized equipment, on the other hand, can rotate θ (45° < θ ≤ 90°), such as... Figure 2As shown, by using the rotational degrees of freedom of special equipment plus the rotational degrees of freedom of the inertial navigation system itself, and by designing a reasonable calibration path and using the Kalman filter algorithm to observe the velocity error, online calibration of parameters such as the scale coefficient and zero bias of the gyroscope and accelerometer can be achieved.

[0121] The entire calibration process does not require disassembling the inertial group (INS). The INS rotates on its own, and special equipment rotates at a certain angle. The online Kalman filter algorithm can estimate parameters such as the scale coefficients and zero bias of the gyroscope and accelerator in real time, and update the calibration parameters in the navigation computer inside the INS. This allows for the calibration of a single-axis rotating INS without disassembly based on the limited rotation of special equipment.

[0122] As an optional implementation of this invention, the parameters of the gyroscope and the accumulator in a single-axis rotating inertial navigation system are estimated in real time using an online Kalman filter algorithm, and the calibration parameters in the navigation computer inside the single-axis rotating inertial navigation system are updated, including:

[0123] Establish a system error model, which includes: determining the state space model based on the attitude error equation and the velocity error equation;

[0124] The attitude error equations include:

[0125]

[0126] in:

[0127] φ n =[φ E φ N φ U ] T ,

[0128]

[0129]

[0130]

[0131] In the formula, φ i (i = E, N, U) represents the attitude error angle, δv i (i = E, N, U) represents the velocity error in the navigation system, L is the geodetic latitude, and ω ie The angular velocity of Earth's rotation. Let be the component of the Earth's rotational angular velocity in the navigation coordinate system. R represents the component of the angular velocity of the navigation coordinate system relative to the Earth coordinate system within the navigation system. M R is the radius of curvature of the Earth's meridian. NLet h be the radius of curvature of the Earth's geoid, h be the geodetic height, and v be the radius of curvature of the Earth's geoid. i (i = E, N, U) represents the navigation system velocity. Let δk be the attitude matrix from system b to system n. gii (i = x, y, z) represents the gyroscope scale coefficient error for each axis. Outputs for each axis gyroscope. Zero bias for each axis gyroscope;

[0132] The velocity error equations include:

[0133]

[0134] in:

[0135] v n =[v E v N v U ] T , M va =f n ×,

[0136]

[0137] In the formula, f i b (i = x, y, z) represents the accelerometer output, δk aii (i = x, y, z) represents the calibration coefficient error of the accelerometers on each axis, δk aij (i = y, z, j = x, y, i ≠ j) represents the accelerometer installation error angle. Zero bias for accelerometers on each axis;

[0138] State-space models include:

[0139]

[0140] Z = HX + V (4)

[0141] in:

[0142] The state transition matrix F is

[0143]

[0144] in

[0145]

[0146]

[0147] The state vector X is taken as:

[0148] X = [φ n δv n δk A δk G ε b ▽ b ] T

[0149] in:

[0150] δk A =[δk axx δk ayx δk ayy δk azx δk azy δk azz ] T

[0151] δk G =[δk gxx δk gyy δk gzz ] T

[0152] The measurement Z is taken as

[0153] Z = [δv] E δv N δv U ] T

[0154] The observation matrix H is taken as

[0155] H = [O 3×3 I3 O 3×15 ]

[0156]

[0157] In the formula, and These are white noise for gyroscope angular velocity measurement and white noise for accelerometer specific force measurement, respectively, V v White noise for velocity measurement;

[0158] Discretize Equation (3) and Equation (4), and use Kalman filtering to estimate them. The optimal estimates of the calibration coefficient errors of the gyroscope and accelerometer and the zero bias parameter are obtained. The estimated data are then used to update the calibration parameters in the navigation computer inside the single-axis rotating inertial navigation system.

[0159] Specifically, the inertial navigation system's rotating frame and special equipment are arranged according to... Figure 3The calibration paths shown are rotated respectively, and then equations (3) and (4) are discretized and estimated by Kalman filtering. The optimal estimates of the calibration coefficient error of the gyroscope and accelerometer and the zero bias parameters can be obtained, thereby realizing the online self-calibration of the key parameters of the single-axis rotating inertial group.

[0160] As an optional embodiment of the present invention, the self-calibration method of a single-axis rotating inertial group based on the limited rotation of special equipment provided in the present invention further includes: setting the rotational speed of the single-axis rotating inertial group frame to 12° / s; and setting the rotational speed of the special equipment to 3° / s.

[0161] In practice, the implementation steps are as follows:

[0162] a) Preparatory work

[0163] (1) The rotational speed of the inertial navigation system frame is set to 12° / s.

[0164] (2) The rotation speed of the special equipment is set to 3° / s

[0165] (3) Special equipment can rotate freely within a range of not less than 45°. If it can rotate 90°, it can provide a better excitation effect for calibration error;

[0166] b) Implementation steps

[0167] (1) Place the special equipment in a test site that is as level as possible;

[0168] (2) Level the special equipment;

[0169] (3) After the inertial navigation system is powered on and the system status is "system ready", send the "self-calibration without disassembly" command.

[0170] (4) After receiving the "self-calibration without disassembly" command, the inertial group begins self-calibration. The inertial device components inside the inertial group perform four-position rotation around the rotation axis: the inertial device components rotate 180° clockwise around the axial axis, remain stationary for 10 seconds, then rotate 180° clockwise again, remain stationary for 10 seconds; then rotate 180° counterclockwise, remain stationary for 10 seconds, and finally rotate 180° counterclockwise, remain stationary for 10 seconds. This process is repeated 5 times.

[0171] (5) Special equipment rotates at a set speed θ (45°≤θ≤90°);

[0172] (6) After the special equipment has been rotated into position, proceed with the operation according to step (4);

[0173] (7) The special equipment returns to the starting position at the set speed;

[0174] (8) After the special equipment has been lowered into place, proceed with the operation in step (4);

[0175] (9) Wait 5 minutes. When the inertial group displays "calibration completed", it means that the inertial group has completed self-calibration and the parameters have been updated.

[0176] (10) Power off the inertial navigation system and end the self-calibration.

[0177] Therefore, the self-calibration method for single-axis rotating inertial navigation systems (INS) based on limited rotation of special equipment provided by this invention addresses the application scenario of self-calibrating critical parameters of INS without disassembly. It designs a self-calibration scheme for INS under limited rotation conditions of special equipment, solving the problem of self-calibrating critical parameters of INS without disassembly and improving the maintainability of INS. It enables self-calibration of key parameters of INS without disassembly, enhancing the autonomous maintenance capability of INS.

[0178] Figure 4 This diagram illustrates the structure of a self-calibration device for a single-axis rotating inertial group based on limited rotation of special equipment, provided in an embodiment of the present invention. This self-calibration device applies the aforementioned method. The following is only a brief description of the structure of the self-calibration device; for other matters not covered herein, please refer to the relevant descriptions in the aforementioned self-calibration method for a single-axis rotating inertial group based on limited rotation of special equipment. Figure 4 The single-axis rotating inertial navigation system self-calibration device based on limited rotation of special equipment provided in this embodiment of the invention includes: a single-axis rotating inertial navigation system and special equipment arranged in a preset manner; wherein:

[0179] A single-axis rotating inertial navigation system (INS) is used to rotate the special equipment according to a preset rotation position after leveling, and to perform self-calibration after each rotation; after the special equipment rotates to a preset angle θ, it is used to rotate the equipment according to a preset rotation position, and to perform self-calibration after each rotation, where the preset angle θ is 45° < θ ≤ 90°; after the special equipment returns to its original position, it is used to rotate the equipment according to a preset rotation position, and to perform self-calibration after each rotation; after estimating the parameters of the gyroscope and the accelerator in the single-axis rotating INS in real time using an online Kalman filter algorithm, the calibration parameters in the navigation computer are updated;

[0180] Special equipment used to rotate at a preset angle θ.

[0181] As an optional embodiment of the present invention, the single-axis rotary inertial navigation system and special equipment are configured in a preset manner as follows:

[0182] The coordinate system is defined as follows: the b coordinate system is defined as the body coordinate system of the inertial navigation system, and the coordinate axes are parallel to the output axes of the inertial devices after the inertial navigation system is calibrated; the n coordinate system is defined as the navigation coordinate system, which is the local horizontal East-North-Sky coordinate system.

[0183] Install a single-axis rotating inertial navigation system on special equipment.

[0184] As an optional embodiment of the present invention, the single-axis rotational inertial navigation system is rotated according to a preset rotation in the following manner, and self-calibrated after each rotation:

[0185] When the single-axis rotating inertial navigation system is powered on and receives the self-calibration command without disassembly, it begins self-calibration. The inertial device components inside the single-axis rotating inertial navigation system perform four-position rotation around the rotation axis: the inertial device components rotate 180° clockwise around the axial axis, remain stationary for 10 seconds, then rotate 180° clockwise again, remain stationary for 10 seconds; then rotate 180° counterclockwise, remain stationary for 10 seconds, and finally rotate 180° counterclockwise, remain stationary for 10 seconds.

[0186] As an optional embodiment of the present invention, the single-axis rotating inertial group self-calibration device based on limited rotation of special equipment provided in this embodiment of the present invention further includes: an estimation unit, which estimates the parameters of the gyroscope and the accumulator in the single-axis rotating inertial group in real time using an online Kalman filter algorithm, and notifies the calibration parameters in the navigation computer inside the single-axis rotating inertial group to be updated:

[0187] Establish a system error model, which includes: determining the state space model based on the attitude error equation and the velocity error equation;

[0188] The attitude error equations include:

[0189]

[0190] in:

[0191] φ n =[φ E φ N φ U ] T ,

[0192]

[0193]

[0194]

[0195] In the formula, φ i (i = E, N, U) represents the attitude error angle, δv i (i = E, N, U) represents the velocity error in the navigation system, L is the geodetic latitude, and ω ie The angular velocity of Earth's rotation. Let be the component of the Earth's rotational angular velocity in the navigation coordinate system. R represents the component of the angular velocity of the navigation coordinate system relative to the Earth coordinate system within the navigation system.M R is the radius of curvature of the Earth's meridian. N Let h be the radius of curvature of the Earth's geoid, h be the geodetic height, and v be the radius of curvature of the Earth's geoid. i (i = E, N, U) represents the navigation system velocity. Let δk be the attitude matrix from system b to system n. gii (i = x, y, z) represents the gyroscope scale coefficient error for each axis. Outputs for each axis gyroscope. Zero bias for each axis gyroscope;

[0196] The velocity error equations include:

[0197]

[0198] in:

[0199] v n =[v E v N v U ] T , M va =f n ×,

[0200]

[0201]

[0202] In the formula, f i b (i = x, y, z) represents the accelerometer output, δk aii (i = x, y, z) represents the calibration coefficient error of the accelerometer for each axis, δk aij (i = y, z, j = x, y, i ≠ j) represents the accelerometer installation error angle. Zero bias for accelerometers on each axis;

[0203] State-space models include:

[0204]

[0205] Z = HX + V (4)

[0206] in:

[0207] The state transition matrix F is

[0208]

[0209] in

[0210]

[0211]

[0212] The state vector X is taken as:

[0213] X = [φ n δv n δk A δk G ε b ▽ b ] T

[0214] in:

[0215] δk A =[δk axx δk ayx δk ayy δk azx δk azy δk azz ] T

[0216] δk G =[δk gxx δk gyy δk gzz ] T

[0217] The measurement Z is taken as

[0218] Z = [δv] E δv N δv U ] T

[0219] The observation matrix H is taken as

[0220] H = [O 3×3 I3 O 3×15 ]

[0221]

[0222] In the formula, and These are white noise for gyroscope angular velocity measurement and white noise for accelerometer specific force measurement, respectively, V v White noise for velocity measurement;

[0223] Discretize Equation (3) and Equation (4), and use Kalman filtering to estimate them. Obtain the optimal estimates of the calibration coefficient errors of the gyroscope and accelerometer and the zero bias parameter, and notify the calibration parameters in the internal navigation computer of the single-axis rotating inertial navigation system to be updated.

[0224] As an optional embodiment of the present invention, the single-axis rotating inertial group is further used to set the rotational speed of the single-axis rotating inertial group frame to 12° / s; the special equipment is further used to set the rotational speed of the special equipment to 3° / s.

[0225] Therefore, the self-calibration device for single-axis rotating inertial navigation systems (INS) based on limited rotation of special equipment provided by this invention addresses the application scenario of self-calibrating important parameters of INS without disassembly. It designs a self-calibration scheme for INS under limited rotation conditions of special equipment, solving the problem of self-calibrating important parameters of INS without disassembly and improving the maintainability of INS. It enables self-calibration of key parameters of INS without disassembly, enhancing the autonomous maintenance capability of INS.

[0226] The above are merely embodiments of this application and are not intended to limit the scope of this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the scope of the claims of this application.

Claims

1. A self-calibration method for a single-axis rotating inertial navigation system based on limited rotation of special equipment, characterized in that, include: Set up the single-axis rotary inertial navigation system and special equipment according to the preset method; After the special equipment is leveled, the single-axis rotational inertial group rotates according to the preset rotation position and performs self-calibration after each rotation. The single-axis rotational inertial navigation system is positioned on the special equipment at a preset angle. After rotation, the rotation is performed according to the preset rotation position, and self-calibration is performed after each rotation, wherein the preset angle is... 45° < <90°; After the special equipment returns to its position, the single-axis rotational inertial navigation system rotates according to the preset rotation position and performs self-calibration after each rotation. The parameters of the gyroscope and the accumulator in the single-axis rotating inertial navigation system are estimated in real time using an online Kalman filter algorithm, and the calibration parameters in the navigation computer inside the single-axis rotating inertial navigation system are updated. in: The single-axis rotational inertial navigation system rotates according to a preset rotation position, and performs self-calibration after each rotation, including: Upon power-up and receipt of the self-calibration command without disassembly, the single-axis rotating inertial device group (SIBG) begins self-calibration. The internal inertial device components of the SIBG perform four-position rotation around the rotation axis: the inertial device components rotate 180° clockwise around the axial axis, remain stationary for 10 seconds, then rotate 180° clockwise again, remain stationary for 10 seconds; then rotate 180° counterclockwise, remain stationary for 10 seconds, and finally rotate 180° counterclockwise again, remain stationary for 10 seconds. The step of estimating the parameters of the gyroscope and the accumulator in the single-axis rotating inertial navigation system in real time using an online Kalman filter algorithm, and updating the calibration parameters in the navigation computer inside the single-axis rotating inertial navigation system includes: A system error model is established, which includes: determining a state-space model based on the attitude error equation and the velocity error equation; The formula of the state-space model is discretized and estimated using the Kalman filter method to obtain the optimal estimates of the calibration coefficient errors of the gyroscope and accelerometer, as well as the zero-bias parameter. The estimated data is then used to update the calibration parameters in the internal navigation computer of the single-axis rotating inertial navigation system.

2. The method according to claim 1, characterized in that, The method of setting up the single-axis rotary inertial navigation system and special equipment according to a preset method includes: The coordinate system is defined as follows: the b coordinate system is defined as the body coordinate system of the inertial navigation system, and the coordinate axes are parallel to the output axes of the inertial devices after the inertial navigation system is calibrated; the n coordinate system is defined as the navigation coordinate system, which is the local horizontal East-North-Sky coordinate system. The single-axis rotational inertial navigation system is installed on the special equipment.

3. The method according to claim 1, characterized in that, The attitude error equation includes: （1） in: ， ， ， ， ， ， ， In the formula, The attitude error angle is... , For the speed error under the navigation system, , Latitude of the earth The angular velocity of Earth's rotation. Let be the component of the Earth's rotational angular velocity in the navigation coordinate system. Let be the component of the angular velocity of the navigation coordinate system relative to the Earth coordinate system in the navigation system. The radius of curvature of the Earth's meridian. The radius of curvature of the Earth's geoid. The height of the earth. For navigation system speed, , Let be the attitude matrix from the b-system to the n-system. This refers to the error of the gyroscope scale coefficients for each axis. , Outputs for each axis gyroscope. , To achieve zero bias for each axis gyroscope, ; The velocity error equation includes: （2） in: ， ， ， ， ， ， ， In the formula, For accelerometer output, , To account for the calibration coefficient error of the accelerometers on each axis, , For the accelerometer installation error angle, , To achieve zero bias for the accelerometers on each axis, ; The state-space model includes: （3） （4） in: State transition matrix for in State vector Take as: in: Measurement Take as Observation matrix Take as ， ， In the formula, and These are white noise measurements for gyroscope angular velocity and white noise measurements for accelerometer specific force. White noise for velocity measurement.

4. The method according to claim 1, characterized in that, Also includes: The rotational speed of the single-axis rotating inertial navigation system frame is set to 12° / s; The rotational speed of the special equipment is set to 3° / s.

5. A self-calibration device for a single-axis rotating inertial navigation system based on limited rotation of special equipment, characterized in that, include: Single-axis rotary inertial navigation system and special equipment configured according to a preset method; wherein: The single-axis rotational inertial navigation system is used to rotate the special equipment according to a preset rotation after leveling, and to perform self-calibration after each rotation; the special equipment rotates according to a preset angle. After rotation, the rotation is performed according to the preset rotation position, and self-calibration is performed after each rotation, wherein the preset angle is... 45° < <90°; After the special equipment returns to its position, it is rotated according to the preset rotation position, and self-calibration is performed after each rotation position; After estimating the parameters of the gyroscope and the accumulator in the single-axis rotation inertial navigation system in real time through the online Kalman filter algorithm, the calibration parameters in the navigation computer are updated; The special equipment is used to adjust the angle as specified. Rotate; in: The single-axis rotational inertial navigation system is rotated according to a preset rotation in the following manner, and self-calibrated after each rotation: Upon power-up and receipt of the self-calibration command without disassembly, the single-axis rotating inertial device group (SIBG) begins self-calibration. The internal inertial device components of the SIBG perform four-position rotation around the rotation axis: the inertial device components rotate 180° clockwise around the axial axis, remain stationary for 10 seconds, then rotate 180° clockwise again, remain stationary for 10 seconds; then rotate 180° counterclockwise, remain stationary for 10 seconds, and finally rotate 180° counterclockwise again, remain stationary for 10 seconds. It also includes: an estimation unit, which estimates the parameters of the gyroscope and the accumulator in the single-axis rotating inertial navigation system in real time using an online Kalman filter algorithm, and notifies the calibration parameters in the navigation computer inside the single-axis rotating inertial navigation system to be updated: A system error model is established, which includes: determining a state-space model based on the attitude error equation and the velocity error equation; The formula of the state-space model is discretized and estimated using the Kalman filter method to obtain the optimal estimates of the calibration coefficient errors of the gyroscope and accelerometer, as well as the zero-bias parameter. The calibration parameters in the internal navigation computer of the single-axis rotating inertial navigation system are then updated.

6. The apparatus according to claim 5, characterized in that, Configure the single-axis rotary inertial navigation system and special equipment according to the preset method as follows: The coordinate system is defined as follows: the b coordinate system is defined as the body coordinate system of the inertial navigation system, and the coordinate axes are parallel to the output axes of the inertial devices after the inertial navigation system is calibrated; the n coordinate system is defined as the navigation coordinate system, which is the local horizontal East-North-Sky coordinate system. The single-axis rotational inertial navigation system is installed on the special equipment.

7. The apparatus according to claim 5, characterized in that, The attitude error equation includes: （1） in: ， ， ， ， ， ， ， In the formula, The attitude error angle is... , For the speed error under the navigation system, , Latitude of the earth The angular velocity of Earth's rotation. Let be the component of the Earth's rotational angular velocity in the navigation coordinate system. Let be the component of the angular velocity of the navigation coordinate system relative to the Earth coordinate system in the navigation system. The radius of curvature of the Earth's meridian. The radius of curvature of the Earth's geoid. The height of the earth. For navigation system speed, , Let be the attitude matrix from the b-system to the n-system. This refers to the error of the gyroscope scale coefficients for each axis. , Outputs for each axis gyroscope. , To achieve zero bias for each axis gyroscope, ; The velocity error equation includes: （2） in: ， ， ， ， ， ， ， In the formula, For accelerometer output, , To account for the calibration coefficient error of the accelerometers on each axis, , For the accelerometer installation error angle, , To achieve zero bias for the accelerometers on each axis, ; The state-space model includes: （3） （4） in: State transition matrix for in State vector Take as: in: Measurement Take as Observation matrix Take as ， ， In the formula, and These are white noise measurements for gyroscope angular velocity and white noise measurements for accelerometer specific force. White noise for velocity measurement.

8. The apparatus according to claim 5, characterized in that, The single-axis rotating inertial group is further configured to set the rotational speed of the single-axis rotating inertial group frame to 12° / s; the special equipment is further configured to set the rotational speed of the special equipment to 3° / s.

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