Fiber-optic gyroscope output compensation method and system based on temperature change rate

Abstract

The invention relates to the technical field of fiber-optic gyroscope output compensation, in particular to a fiber-optic gyroscope output compensation method and system based on a temperature change rate, which can improve the output stability and accuracy of a fiber-optic gyroscope in different temperature environments. According to the method, the temperature change rate of the gyroscope is monitored in real time, and the fitting relation between the temperature change rate and the gyroscope drift value is established, so that precise compensation of gyroscope output is realized, and the output stability and accuracy of the gyroscope in different temperature environments are improved; the compensated gyroscope output value is more stable, and the overall stability and reliability of the inertial navigation system are improved.

Description

Technical Field

[0001] The present invention relates to the technical field of fiber optic gyroscope output compensation, and in particular to a fiber optic gyroscope output compensation method and system based on temperature change rate. Background Art

[0002] As the core component of the inertial navigation system, the output stability of the gyroscope is crucial to navigation accuracy. However, the output of the gyroscope is easily affected by changes in ambient temperature, causing the output value to drift, thereby affecting the accuracy and reliability of the navigation system. Therefore, how to effectively compensate for the output drift of the gyroscope caused by temperature changes is a technical problem that needs to be solved urgently in the current field of inertial navigation technology.

[0003] In a fiber optic gyroscope, the refractive index of each point of the fiber optic coil changes with the change of temperature. Due to the change of refractive index, the two light waves propagating in opposite directions pass through the point at different times and have different phases, forming a zero bias error, which is the Shupe effect. The influence of temperature on the gyroscope mainly includes two aspects, one is constant temperature and the other is variable temperature. At constant temperature points with different temperatures, the zero position of the fiber optic gyroscope output has a certain drift, but compared with the variable temperature stage, the zero position drift of the gyroscope is smaller. When the temperature changes, the drift of the gyroscope output changes significantly, so the output of the gyroscope must be compensated for variable temperature. The existing fiber optic gyroscope temperature compensation method is not accurate. Summary of the invention

[0004] In view of this, the present invention provides a method and system for compensating an output of a fiber optic gyroscope based on a temperature change rate, which can improve the output stability and accuracy of the fiber optic gyroscope under different temperature environments.

[0005] To achieve the above object, the present invention provides a method for compensating an output of a fiber optic gyroscope based on a temperature change rate, comprising the following steps:

[0006] Set up the test conditions for the gyroscope and record the temperature changes and angular velocity output;

[0007] Get the temperature change rate and gyro raw output;

[0008] Determine gyro drift value;

[0009] A fitting relationship between the temperature change rate and the gyro drift value is established; the fitting relationship is a second-order fitting; and the gyro output value is compensated using the fitting relationship.

[0010] The test conditions include static heat preservation and variable temperature treatment at different temperatures.

[0011] Wherein, the temperature change rate is obtained by smoothing the temperature output of the gyroscope.

[0012] The specific method of establishing the fitting relationship between the temperature change rate and the gyro drift value is: perform a second-order fitting on the gyro drift value and the temperature change rate to obtain the fitting formulas in the cooling and heating processes, respectively.

[0013] Among them, the gyro output value at the time of temperature change minus the gyro output value at 35℃ steady state is used as the gyro drift value dω caused by temperature change, and this value and the gyro temperature change rate dt are used for second-order fitting, specifically: dω=p0+p1*dt-p2*dt 2 , where p0, p1, and p2 represent the fitting parameters in the least squares method.

[0014] The present invention also provides a fiber optic gyroscope output compensation system based on temperature change rate, the system is used to execute the fiber optic gyroscope output compensation method based on temperature change rate described in the present invention; the system includes: a temperature monitoring module, used to monitor the temperature change of the gyroscope in real time; a data processing module, used to calculate the temperature change rate and determine the gyroscope drift value; a fitting module, used to establish a fitting relationship between the temperature change rate and the gyroscope drift value; and a compensation module, used to compensate the gyroscope output value using the fitting relationship.

[0015] Beneficial effects:

[0016] 1. The method of the present invention realizes accurate compensation of gyro output by real-time monitoring of the temperature change rate of the gyroscope and establishing a fitting relationship between the temperature change rate and the gyroscope drift value, thereby improving the output stability and accuracy of the gyroscope under different temperature environments; the compensated gyroscope output value is more stable, which is conducive to improving the overall stability and reliability of the inertial navigation system.

[0017] 2. The method of the present invention is applicable to gyroscopes of different models and can show good compensation effects under different temperature environments.

[0018] 3. The system of the present invention is used to implement the method of the present invention, by real-time monitoring the temperature change rate of the gyroscope and establishing a fitting relationship between the temperature change rate and the gyroscope drift value, thereby achieving accurate compensation for the gyroscope output and improving the output stability and accuracy of the gyroscope under different temperature environments; the compensated gyroscope output value is more stable, which is beneficial to improving the overall stability and reliability of the inertial navigation system.

[0019] 4. The system of the present invention is applicable to gyroscopes of different models and can show good compensation effect under different temperature environments. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 Schematic diagram of gyroscope temperature change under the test conditions of the method embodiment of the present invention.

[0021] Figure 2Schematic diagram of the gyroscope temperature change rate under the test conditions of the method embodiment of the present invention.

[0022] Figure 3 It is a schematic diagram of the original output of the gyroscope in the test conditions of the embodiment of the method of the present invention.

[0023] Figure 4 The figure is a schematic diagram of fitting the gyro drift with negative temperature change rate in the modeling of gyro output and temperature change rate according to an embodiment of the present invention.

[0024] Figure 5 The diagram is a schematic diagram of the fitting of the gyro drift with a positive temperature change rate in the modeling of the gyro output and the temperature change rate according to an embodiment of the present invention.

[0025] Figure 6 Schematic diagram of gyroscope output comparison in the embodiment of the method of the present invention. DETAILED DESCRIPTION

[0026] The present invention is described in detail below with reference to the accompanying drawings and embodiments.

[0027] The present invention provides a method for compensating an output of an optical fiber gyroscope based on a temperature change rate, comprising the following steps:

[0028] Setting the test conditions of the gyroscope: In order to obtain the variable temperature characteristics of the gyroscope output, it is necessary to create a variable temperature environment for the gyroscope. The gyroscope is placed in an incubator. In this embodiment, the incubator temperature is first set to 65°C and kept static for 1.5 hours; then the temperature is lowered to 15°C, and then raised to 35°C and kept warm for 2 hours. During this process, the temperature change and angular velocity output of the gyroscope are recorded. The temperature change of the gyroscope during the whole process is as follows: Figure 1 shown.

[0029] Obtaining the temperature change rate and the original output of the gyroscope: The temperature output of the gyroscope is smoothed for 100 seconds to obtain the temperature change rate. In this embodiment, the temperature change rate of the gyroscope is as follows: Figure 2 The angular velocity output of the gyroscope is smoothed for 100 seconds to obtain the original output of the gyroscope. The original output of the gyroscope in this embodiment is as follows: Figure 3 shown.

[0030] Determine the gyro drift value: From the temperature change rate and the original gyro output, it can be known that when the gyro is in a constant temperature state at different temperatures, the gyro output is almost stable; when the gyro is in a variable temperature state, the gyro output has a relatively large change. Taking the gyro output value at a steady state of 35°C as the benchmark, calculate the difference between the gyro output value at the variable temperature moment and the benchmark value as the gyro drift value caused by the variable temperature.

[0031] Establish a fitting relationship: Perform a second-order fitting on the gyro drift value and the temperature change rate, and obtain the fitting formulas in the cooling and heating processes. In this embodiment, the gyro output value at the temperature change moment minus the gyro output value at 35°C steady state is used as the gyro drift value dω caused by the temperature change, and this value and the gyro temperature change rate dt are used for a second-order fitting, specifically: dω=p0+p1*dt-p2*dt 2 , where p0, p1, and p2 represent the fitting parameters in the least squares method.

[0032] Specifically, the fitting relationship between the cooling temperature change rate and the gyro drift value is as follows: Figure 4 As shown, the fitting formula calculated in this embodiment is dω=0.01+22.67*dt-889.63*dt 2 ;

[0033] The fitting relationship between the heating temperature change rate and the gyro drift value is as follows: Figure 5 As shown, the fitting formula calculated in this embodiment is dω=-0.009+29.41*dt+229.01*dt 2 .

[0034] Compensate gyro output: Use the established fitting formula to compensate the gyro output value to eliminate the impact of temperature change on the gyro output.

[0035] Specifically, the gyro output value is compensated using the heating and cooling fitting formula. The compensated gyro output value is as follows: Figure 6 shown.

[0036] The method of the present invention further includes a step of evaluating the compensation effect, calculating the mean and variance of the gyro output values ​​before and after compensation, and evaluating the compensation effect. In this embodiment, the mean and variance of the gyro output values ​​before and after compensation are calculated respectively. By comparing the gyro output value after compensation with the original gyro output value (such as the gyro output value comparison table shown in Table 1), the mean is more accurate and the standard deviation is smaller, which can effectively reduce the influence of the gyro output on the temperature change.

[0037] Table 1 Comparison of gyro output values

[0038] Mean Standard Deviation Gyro output raw value 18.7571 0.0844 Gyro output value after compensation 18.7699 0.0164

[0039] The present invention also provides a fiber optic gyro output compensation system based on temperature change rate, which is used to implement the method of the present invention, by real-time monitoring the temperature change rate of the gyro, and establishing a fitting relationship between the temperature change rate and the gyro drift value, thereby achieving accurate compensation for the gyro output and improving the output stability and accuracy of the gyro under different temperature environments. The system of the present invention includes:

[0040] The temperature monitoring module is used to monitor the temperature change of the gyroscope in real time; the data processing module is used to calculate the temperature change rate and determine the gyroscope drift value; the fitting module is used to establish the fitting relationship between the temperature change rate and the gyroscope drift value; the compensation module is used to compensate the gyroscope output value using the fitting relationship.

[0041] In summary, the above are only preferred embodiments of the present invention and are not intended to limit the protection scope of the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principles of the present invention should be included in the protection scope of the present invention.

Claims

1. A method for compensating an output of a fiber optic gyroscope based on a temperature change rate, characterized in that: The following steps are involved: Set up the test conditions for the gyroscope and record the temperature changes and angular velocity output; Get the temperature change rate and gyro raw output; Determine gyro drift value; Establishing a fitting relationship between the temperature change rate and the gyro drift value; the fitting relationship is a second-order fitting; The gyro output value is compensated using the fitting relationship.

2. The method according to claim 1, characterized in that The test conditions include static temperature preservation and variable temperature treatment at different temperatures.

3. The method according to claim 1 or 2, characterized in that ,The temperature change rate is obtained by smoothing the temperature output of the gyro.

4. The method according to claim 3, characterized in that ,The specific way of establishing the fitting relationship between the ,temperature change rate and the gyro drift value is as follows: ,perform a second-order fitting on the gyro drift value and the ,temperature change rate, and obtain the fitting formula in the ,cooling and heating processes, respectively.

5. The method according to claim 4, characterized in that , the gyro output value at the time of temperature change minus the gyro output value at 35℃ steady state is used as the gyro drift value dω caused by temperature change, and this value and the gyro temperature change rate dt are used for second-order fitting, specifically: dω=p0+p1*dt-p2*dt 2 , where p0, p1, and p2 represent the fitting parameters in the least squares method.

6. A fiber optic gyroscope output compensation system based on temperature change rate, characterized in that: The system is used to execute the fiber optic gyroscope output compensation method based on temperature change rate as described in any one of claims 1 to 5 above; the system includes: a temperature monitoring module, used to monitor the temperature change of the gyroscope in real time; a data processing module, used to calculate the temperature change rate and determine the gyroscope drift value; a fitting module, used to establish a fitting relationship between the temperature change rate and the gyroscope drift value; and a compensation module, used to compensate the gyroscope output value using the fitting relationship.

Images