A method for calibrating the scale factor and installation bias angle of a silicon micro inertial navigation system gyro

Abstract

A method for calibrating the scale coefficients and installation deflection angles of a silicon micro inertial navigation system (INS) gyroscope is disclosed. The method employs the following steps: First, a coarse calibration of the gyroscope's scale coefficients and installation deflection angles is performed using a limited number of rotation sequences and fixed positions. The corresponding error values ​​are then calculated after the coarse calibration. Second, based on the coarse calibration, a dynamic fine calibration test is conducted using a dual-axis automatic turntable. The rotation sequence of angular rates is designed to complete the calibration test in the shortest possible time, thereby improving calibration accuracy. This invention proposes a method for calibrating the scale coefficients and installation deflection angles of a silicon micro gyroscope, which has good versatility and engineering applicability, improves calibration accuracy and work efficiency, and enhances the performance of the silicon micro INS.

Description

Technical Field

[0001] This invention belongs to the field of inertial measurement technology and relates to a method for calibrating the gyroscope scale coefficients and installation deflection angle of a silicon micro inertial navigation system. Background Technology

[0002] Silicon micro inertial navigation systems based on silicon micro gyroscopes and silicon micro accelerometers offer advantages such as small size, light weight, low power consumption, low cost, and high integration, making them one of the key development directions for future inertial navigation systems. Currently, foreign silicon micro accelerometers have reached navigation-grade levels, and silicon micro gyroscopes have reached tactical-grade levels. These products are widely used in tactical missiles, smart munitions, guided projectiles, and aircraft attitude control. The US military plans to use silicon micro inertial devices in 90% of its future guided weapons.

[0003] Inertial sensors exhibit predictable errors in practical use. These error coefficients need to be measured through certain experiments and used to correct the inertial sensor's measurements. This process is called calibration testing. Calibration testing can be divided into two parts: rate testing and position testing. Rate testing is used to calibrate the gyroscope's scale coefficient error and installation angle error, while position testing is used to calibrate the accelerometer's scale coefficient error, installation angle error, and the gyroscope's G-related errors.

[0004] High angular rate noise and hidden measurement information are among the output characteristics of silicon micro gyroscopes. The calibration accuracy of silicon micro gyroscopes obtained by using the traditional rotation test method is poor and cannot meet the system requirements. Summary of the Invention

[0005] The purpose of this invention is to provide a calibration method that can improve the calibration accuracy of the scale coefficient and installation angle of silicon micro gyroscopes.

[0006] The technical solution of the present invention is: a method for calibrating the gyroscope scale coefficients and installation deflection angle of a silicon micro inertial navigation system, characterized in that the method includes the following steps:

[0007] Step 1: Use a turntable to coarsely calibrate the scale coefficients and installation angle of the silicon micro gyroscope;

[0008] Step 2: Rotate the silicon micro inertial navigation system in both the forward and reverse directions with the same angular rate as the center of the X-axis, Y-axis and Z-axis, and collect the angular rate value output by the gyroscope of the silicon micro inertial navigation system when rotating along each axis;

[0009] Step 3: Use the following formula to correct the gyroscope scale coefficient.

[0010]

[0011] Where: K gx新 K gy新K gz新 These are the corrected scale coefficients for the X-axis gyroscope, Y-axis gyroscope, and Z-axis gyroscope, respectively, K. gx旧 K gy旧 K gz旧 These are the calibration coefficients for the X-axis gyroscope, Y-axis gyroscope, and Z-axis gyroscope before correction. These are the actual output angular rates of the local axis for rotation in the positive and negative directions of the X, Y, and Z axes, respectively. These are the angular rates of rotation of the turntable in the forward and reverse directions.

[0012] Step 4: Rotate the silicon micro inertial navigation system in both the forward and reverse directions with the same angular rate as the center of the X-axis, Y-axis and Z-axis respectively, and collect the angular rate values ​​of the gyroscope output of the silicon micro inertial navigation system on the other two axes when rotating along one of the axes respectively.

[0013] Step 5: Correct the gyroscope mounting angle according to the following formula:

[0014]

[0015] Among them: A xy新 A yx新 A yz新 A zy新 A xz新 A zx新 These are the corrected mounting angles of the gyroscope, A. xy旧 A yx旧 A yz旧 A zy旧 A xz旧 A zx旧 These are the installation angles of the gyroscope before correction. These represent the angular rates output by the pitch and roll axes, respectively, when the yaw axis rotates. These represent the angular rates output by the pitch and roll axes, respectively, during pitch axis rotation. These are the angular rate values ​​output by the pitch and yaw axes, respectively, when the roll axis rotates.

[0016] As an improvement to this technical solution, the silicon micro inertial navigation system has an angular rate of 200° / s along the X, Y, and Z axes.

[0017] As an improvement to this technical solution, the angular rate value output by the silicon micro inertial navigation system gyroscope is calculated based on the angular increment collected continuously for 1 minute.

[0018] The beneficial effects of this invention are as follows: This invention provides a calibration method for the gyroscope calibration coefficients and installation deflection angle of a silicon micro inertial navigation system. This invention employs a dynamic calibration method to improve the signal-to-noise ratio of the silicon micro gyroscope, possessing good versatility and engineering applicability, improving calibration accuracy and work efficiency, and enhancing the performance of the silicon micro inertial navigation system. Detailed Implementation

[0019] The present invention will be further described in detail below with reference to specific embodiments.

[0020] The method includes the following steps:

[0021] Step 1: Using a dual-axis automatic turntable, the scale coefficient and installation angle of the silicon micro gyroscope are coarsely calibrated through rotational testing;

[0022] Step 2: Perform precise calibration of the gyroscope scale coefficients under an angular rate of ±200° / s. Select the initial position ENU of the silicon micro inertial navigation system, and rotate the system along the Z, X, and Y axes at an angular rate of ±200° / s. This angular rate value represents the gyroscope's angular rate measurement range and the turntable's angular rate measurement range. Collect data for 1 minute for each axis at each angular rate. The formula for calculating the gyroscope scale coefficient correction is as follows:

[0023]

[0024]

[0025] In the above formula,

[0026] K gx新 K gy新 K gz新 These are the new scale coefficients for the X-axis gyroscope, Y-axis gyroscope, and Z-axis gyroscope, respectively, in rad / ^.

[0027] K gx旧 K gy旧 K gz旧 These are the old scale coefficients for the X-axis gyroscope, Y-axis gyroscope, and Z-axis gyroscope, respectively, in rad / ^.

[0028] The actual output of the positive and negative rotation of the X, Y, and Z axes is the average value of the cumulative angular increment of the local axis over 10 seconds and 1 minute (positive for positive rotation and negative for negative rotation), in rad.

[0029] The average value of the cumulative angular increment over 1 minute for 10 seconds of clockwise and counterclockwise rotation of the turntable (positive for clockwise rotation and negative for counterclockwise rotation), in rad.

[0030] Step 3: Perform precise calibration of the gyroscope mounting angle under an angular rate of ±200° / s. Select the initial position ENU of the silicon micro inertial navigation system, and rotate the system's yaw, pitch, and roll axes at an angular rate of ±200° / s respectively. Collect 1 minute of data for each axis at each angular rate. The formula for calculating the gyroscope mounting angle correction is as follows:

[0031]

[0032]

[0033] A xy新 A yx新 A yz新 A zy新 A xz新 A zx新 These are the newly installed deflection angles of the gyroscope, in rad.

[0034] A xy旧 A yx旧 A yz旧 A zy旧 A xz旧 A zx旧 These are the old installation deflection angles of the gyroscope, in rad.

[0035] The values ​​are the average values ​​of the cumulative angle increments of the pitch and roll axes over 10 seconds over 1 minute when the yaw axis rotates at ±200° / s, respectively, in rad.

[0036] The values ​​are the average of the cumulative angle increments of the pitch and roll axes over 10 seconds over 1 minute, respectively, when the pitch axis rotates at ±200° / s. The unit is rad.

[0037] These are the average values ​​of the cumulative angle increments of the pitch and yaw axes over 1 minute, taken as the roll axis rotates at ±200° / s. The unit is rad.

Claims

1. A method for calibrating the gyroscope calibration coefficients and installation deflection angle of a silicon micro inertial navigation system, characterized in that, The method includes the following steps: Step 1: Use a turntable to coarsely calibrate the scale coefficients and installation angle of the silicon micro inertial navigation system gyroscope; Step 2: Rotate the silicon micro inertial navigation system in both the forward and reverse directions with the same angular rate as the center of the X-axis, Y-axis and Z-axis, and collect the angular rate value output by the gyroscope of the silicon micro inertial navigation system when rotating along each axis; Step 3: Use the following formula to correct the gyroscope scale coefficient. in: These are the corrected positive scale coefficients for the X-axis gyroscope, Y-axis gyroscope, and Z-axis gyroscope, respectively. These are the negative scale coefficients after correction for the ×-axis gyroscope, Y-axis gyroscope, and Z-axis gyroscope, respectively. These are the positive scale coefficients of the X-axis gyroscope, Y-axis gyroscope, and Z-axis gyroscope before correction. These are the negative scale coefficients of the X-axis gyroscope, Y-axis gyroscope, and Z-axis gyroscope before correction, respectively. These are the actual output angular rates of the local axis for rotation in the positive and negative directions of the X, Y, and Z axes, respectively. These are the angular rates of rotation of the turntable in the forward and reverse directions. Step 4: Rotate the silicon micro inertial navigation system in both the forward and reverse directions with the same angular rate as the center of the X-axis, Y-axis and Z-axis respectively, and collect the angular rate values ​​of the gyroscope output of the silicon micro inertial navigation system on the other two axes when rotating along one of the axes respectively. Step 5: Correct the gyroscope mounting angle according to the following formula: Among them: A xy新 A yx新 A yz新 A zy新 A xz新 A zx新 These are the corrected mounting angles of the gyroscope, A. xy旧 A yx旧 A yz旧 A zy旧 A xz旧 A zx旧 These are the installation angles of the gyroscope before correction. These represent the angular rates output by the pitch and roll axes, respectively, when the yaw axis rotates. These represent the angular rates output by the pitch and roll axes, respectively, during pitch axis rotation. These are the angular rate values ​​output by the pitch and yaw axes, respectively, when the roll axis rotates.

2. The method for calibrating the gyroscope scale coefficients and installation deflection angle of a silicon micro inertial navigation system according to claim 1, characterized in that: The silicon micro inertial navigation system has an angular rate of 200° / s along the X, Y, and Z axes.

3. The method for calibrating the gyroscope scale coefficients and installation deflection angle of a silicon micro inertial navigation system according to claim 1, characterized in that: The angular rate value output by the gyroscope in the silicon micro inertial navigation system is calculated based on the angular increment collected continuously for 1 minute.

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