Optical inertial navigation starting stage element level temperature compensation method

Abstract

The invention relates to an element-level temperature compensation method in an optical inertial navigation starting stage. The element-level temperature compensation method comprises the following steps: step 1, acquiring a gyroscope output pulse P sequence, a gyroscope temperature T1 sequence, a gyroscope temperature T2 sequence and a sampling interval t; step 2, smoothing time T is taken, and smoothing processing is carried out; step 3, acquiring the variation dP of the output pulse of the gyroscope after smoothing, the variation dT1 of the temperature T1 and the variation dT2 of the temperature T2; step 4, establishing a function of the temperature compensation model dP about dT1 and dT2; 5, fitting to obtain a temperature compensation coefficient of the temperature compensation model; step 6, repeating the step 1 for m + n times; step 7, repeating the step 2 to the step 5 on the first m groups of data obtained in the step 6, if mgt; and 1, averaging the temperature compensation coefficients obtained by m times of fitting to obtain a final temperature compensation model. The method can improve the alignment precision of the initial alignment stage and guarantee the navigation precision of the high-precision inertial navigation equipment.

Description

Technical Field

[0001] The invention belongs to the technical field of inertial navigation systems, and relates to a component-level temperature compensation method, in particular to a component-level temperature compensation method in an optical inertial navigation startup phase. Background Art

[0002] In the inertial navigation system, the inertial measurement element installed on the inertial platform is a heat-generating device. The function of the inertial platform temperature control is to ensure the stability of the temperature field inside the inertial platform by controlling the air temperature around the inertial platform. However, during the startup process, the temperature rise generated by the gyroscope itself cannot be stabilized by controlling the temperature field inside the platform. It is caused by the heating of the internal components when the gyroscope starts working. The temperature change can reach 3-5℃ within 1 hour of starting work. If it is not eliminated, it will directly affect the results of the initial alignment, thereby affecting the navigation accuracy of the high-precision inertial navigation equipment.

[0003] The usual practice for temperature compensation of gyroscopes is to place the gyroscope in an incubator with an isolation base. After the gyroscope temperature reaches equilibrium, the temperature of the incubator is changed to simulate the change in the gyroscope's ambient temperature to establish the relationship between the gyroscope zero bias and the ambient temperature as a temperature compensation model. This model is suitable for compensating for the change in gyroscope zero bias caused by the change in the internal temperature of the inertial platform after the gyroscope temperature reaches equilibrium. By comparing the relationship curve between the gyroscope zero bias and the self-heating temperature with the relationship curve between the gyroscope zero bias and the ambient temperature, it can be found that the trend of the gyroscope zero bias changing with the self-heating temperature is significantly different from the trend of the gyroscope zero bias changing with the ambient temperature, and even in the opposite direction. Therefore, it is necessary to establish a temperature compensation model in the startup phase to ensure the accuracy of the initial alignment.

[0004] Therefore, the present invention proposes a component-level temperature compensation method during the startup phase of an optical inertial navigation system, which can overcome the above problems.

[0005] After searching, no prior art documents identical or similar to the present invention were found. Summary of the invention

[0006] The purpose of the present invention is to overcome the shortcomings of the prior art and propose a component-level temperature compensation method in the startup phase of an optical inertial navigation system. By establishing a temperature compensation model, the zero bias change of the gyroscope caused by the self-temperature rise is compensated, the alignment accuracy in the initial alignment phase is improved, and the navigation accuracy of a high-precision inertial navigation device is guaranteed.

[0007] The present invention solves the practical problem by adopting the following technical solutions:

[0008] A component-level temperature compensation method for an optical inertial navigation system during its startup phase comprises the following steps:

[0009] Step 1, obtaining the gyroscope output pulse P sequence and gyroscope temperature T1 sequence, gyroscope temperature T2 sequence from the start-up to the temperature reaching equilibrium stage, and the sampling interval t;

[0010] Step 2, taking the smoothing time T, smoothing the gyroscope output pulse sequence P, the gyroscope temperature sequence T1, and the gyroscope temperature sequence T2;

[0011] Step 3, obtaining the change dP of the smoothed gyroscope output pulse, the change dT1 of the temperature T1, and the change dT2 of the temperature T2;

[0012] Step 4, establish the temperature compensation model dP as a function of dT1 and dT2;

[0013] Step 5, fitting to obtain the temperature compensation coefficient of the temperature compensation model;

[0014] Step 6, repeat step 1 for m+n times;

[0015] Step 7: Repeat steps 2 to 5 for the first m groups of data obtained in step 6. If m>1, average the temperature compensation coefficients obtained by m fittings to obtain the final temperature compensation model.

[0016] Moreover, the specific method of step 1 is:

[0017] Obtain the data sequence P, gyroscope temperature T1, and gyroscope temperature T2 of the gyroscope from startup to temperature equilibrium stage, which is about 6 hours in total, and the sampling interval t is 1s;

[0018] Moreover, the specific method of step 2 is:

[0019] Take the smoothing time T = 100s, and get the smoothed P 100 、T1 100 、T2 100 ;

[0020] Moreover, the specific method of step 3 is:

[0021] Take 100s smoothed P 100 、T1 100 、T2 100 The changes of dP, dT1, dT1;

[0022] Moreover, the specific method of step 4 is:

[0023] The temperature compensation model is: dP = 0.5*(1-exp(-A1*dT1))+0.5*(1-exp(-A2*dT2));

[0024] Moreover, the specific method of step 5 is:

[0025] The temperature compensation coefficients A1 and A2 of the temperature compensation model are obtained by fitting using the Matlab function lsqcurvefit;

[0026] Moreover, the specific method of step 6 is:

[0027] The total number of repetitions is 3 times, m = 1, n = 2;

[0028] m is the number of modeling repetitions; n is the number of validation repetitions;

[0029] Moreover, the specific method of step 7 is:

[0030] Using the first startup data, after smoothing for 100 seconds, the temperature compensation coefficients A1 = -0.0002, A2 = 0.0020 are obtained;

[0031] Moreover, after step 7, the method further includes the following steps:

[0032] Step 8: Substitute the final temperature compensation model obtained in step 7 into the n sets of data sequences in step 6 to verify the temperature compensation effect.

[0033] Advantages and beneficial effects of the present invention:

[0034] 1. The present invention solves the problem that the temperature compensation model established under the condition of ambient temperature change is used for temperature compensation during the temperature rise stage of the gyroscope, resulting in unsatisfactory temperature compensation effect or even compensation error.

[0035] 2. The present invention establishes an accurate gyroscope temperature compensation model in the startup phase to improve the alignment accuracy in the initial alignment phase

[0036] 3. The present invention improves the initial alignment accuracy of the inertial navigation system, shortens the initial alignment time of the inertial navigation system, and improves the startup performance, especially the short-term startup characteristics. BRIEF DESCRIPTION OF THE DRAWINGS

[0037] Figure 1 This is a smooth curve chart of the first set of modeling data before and after temperature compensation for 100 seconds of the present invention;

[0038] Figure 2 A temperature curve diagram corresponding to the first set of modeling data of the present invention;

[0039] Figure 3 This is a smoothed curve chart of the second group of cold start verification data before and after temperature compensation for 100 seconds of the present invention;

[0040] Figure 4 is a temperature curve diagram corresponding to the second group of cold start data of the present invention;

[0041] Figure 5 This is a smooth curve chart of the third set of hot start verification data before and after temperature compensation for 100 seconds of the present invention;

[0042] Figure 6 This is a temperature curve diagram corresponding to the third set of hot start data of the present invention. DETAILED DESCRIPTION

[0043] The following is a further description of the embodiments of the present invention:

[0044] A component-level temperature compensation method for an optical inertial navigation system during its startup phase comprises the following steps:

[0045] Step 1, obtaining the gyroscope output pulse P sequence and gyroscope temperature T1 sequence, gyroscope temperature T2 sequence from the start-up to the temperature reaching equilibrium stage, and the sampling interval t;

[0046] The specific method of step 1 is:

[0047] Obtain the data sequence P, gyroscope temperature T1, and gyroscope temperature T2 of the gyroscope from startup to temperature equilibrium stage, which is about 6 hours in total, and the sampling interval t is 1s;

[0048] Step 2, taking the smoothing time T, smoothing the gyroscope output pulse sequence P, the gyroscope temperature sequence T1, and the gyroscope temperature sequence T2;

[0049] The specific method of step 2 is:

[0050] Take the smoothing time T = 100s, and get the smoothed P 100 、T1 100 、T2 100 ;

[0051] Step 3, obtaining the change dP of the smoothed gyroscope output pulse, the change dT1 of the temperature T1, and the change dT2 of the temperature T2;

[0052] The specific method of step 3 is:

[0053] Take 100s smoothed P 100 、T1 100 、T2 100 The changes of dP, dT1, dT1;

[0054] Step 4, establish the temperature compensation model dP as a function of dT1 and dT2;

[0055] The specific method of step 4 is:

[0056] The temperature compensation model is: dP = 0.5*(1-exp(-A1*dT1))+0.5*(1-exp(-A2*dT2));

[0057] Step 5, fitting to obtain the temperature compensation coefficient of the temperature compensation model;

[0058] The specific method of step 5 is:

[0059] The temperature compensation coefficients A1 and A2 of the temperature compensation model are obtained by fitting using the Matlab function lsqcurvefit;

[0060] Step 6, repeat step 1 for m+n times;

[0061] The specific method of step 6 is:

[0062] The total number of repetitions is 3 times, m = 1, n = 2;

[0063] m is the number of modeling repetitions; n is the number of validation repetitions;

[0064] Step 7: Repeat steps 2 to 5 for the first m groups of data obtained in step 6. If m>1, average the temperature compensation coefficients obtained by m fittings to obtain the final temperature compensation model.

[0065] The specific method of step 7 is:

[0066] Using the first startup data, after smoothing for 100 seconds, the temperature compensation coefficients A1 = -0.0002, A2 = 0.0020 are obtained;

[0067] Step 8: Substitute the final temperature compensation model obtained in step 7 into the n sets of data sequences in step 6 to verify the temperature compensation effect.

[0068] In this embodiment, if Figures 1 to 6 As shown in the figure, the final temperature compensation model is brought into the second group of cold start and the third group of hot start data for compensation. It can be clearly seen from the 100-second smooth pulse curves before and after gyroscope compensation that the gyroscope output is affected by temperature during the startup phase, and the part of the gyroscope affected by temperature is corrected after compensation; the curves before and after hot start compensation show that the established model is applicable to both cold start and hot start states.

[0069] In this embodiment, the temperature compensation model is used to compensate the first group of modeling data. The 100-second smooth curves of the gyroscope output before and after temperature compensation are as follows: Figure 1 The corresponding temperature curve is as follows Figure 2 .

[0070] The temperature compensation model is used to compensate the second group of cold start verification data. The 100-second smooth curves of the gyroscope output before and after temperature compensation are as follows: Figure 3 The corresponding temperature curve is as follows Figure 4 .

[0071] The temperature compensation model is used to compensate the third group of hot start verification data. The 100-second smooth curves of the gyroscope output before and after temperature compensation are as follows: Figure 5The corresponding temperature curve is as follows Figure 6 .

[0072] It is obvious from the figure that the gyroscope output is affected by temperature during the cold start stage, and the part of the gyroscope affected by temperature is corrected after compensation; the temperature compensation model is applicable to both cold start and hot start states.

[0073] It should be emphasized that the embodiments of the present invention are illustrative rather than restrictive. Therefore, the present invention includes but is not limited to the embodiments described in the specific implementation manner. Any other implementation manners derived by those skilled in the art based on the technical solution of the present invention also fall within the scope of protection of the present invention.

Claims

1. A component-level temperature compensation method for an optical inertial navigation system during its startup phase, characterized in that: The following steps are involved: Step 1, obtaining the gyroscope output pulse P sequence and gyroscope temperature T1 sequence, gyroscope temperature T2 sequence from the start-up to the temperature reaching equilibrium stage, and the sampling interval t; Step 2, taking the smoothing time T, smoothing the gyroscope output pulse sequence P, the gyroscope temperature sequence T1, and the gyroscope temperature sequence T2; Step 3, obtaining the change dP of the smoothed gyroscope output pulse, the change dT1 of the temperature T1, and the change dT2 of the temperature T2; Step 4, establish the temperature compensation model dP as a function of dT1 and dT2; Step 5, fitting to obtain the temperature compensation coefficient of the temperature compensation model; Step 6, repeat step 1 for m+n times; Step 7: Repeat steps 2 to 5 for the first m groups of data obtained in step 6. If m>1, average the temperature compensation coefficients obtained from the m fittings to obtain the final temperature compensation model.

2. The component-level temperature compensation method for an optical inertial navigation system during startup according to claim 1, characterized in that: The specific method of step 1 is: The data sequence P, gyroscope temperature T1, and gyroscope temperature T2 of the gyroscope are obtained from the startup to the temperature equilibrium stage, which is about 6 hours, and the sampling interval t is 1 second.

3. The component-level temperature compensation method for an optical inertial navigation system during startup according to claim 1, characterized in that: The specific method of step 2 is: Take the smoothing time T = 100s, and get the smoothed P 100 、T1 100 、T2 100 .

4. The component-level temperature compensation method for an optical inertial navigation system during startup according to claim 1, characterized in that: The specific method of step 3 is: Take 100s smoothed P 100 、T1 100 、T2 100 The changes in dP, dT1, dT1.

5. The component-level temperature compensation method for an optical inertial navigation system during startup according to claim 1, characterized in that: The specific method of step 4 is: The temperature compensation model is: dP = 0.5*(1-exp(-A1*dT1))+0.5*(1-exp(-A2*dT2)).

6. The component-level temperature compensation method for an optical inertial navigation system during startup according to claim 1, characterized in that: The specific method of step 5 is: The temperature compensation coefficients A1 and A2 of the temperature compensation model are obtained by fitting using the Matlab function lsqcurvefit.

7. The component-level temperature compensation method for an optical inertial navigation system during startup according to claim 1, characterized in that: The specific method of step 6 is: The total number of repetitions is 3 times, m = 1, n = 2; m is the number of modeling repetitions; n is the number of validation repetitions.

8. The component-level temperature compensation method for an optical inertial navigation system during startup according to claim 1, characterized in that: The specific method of step 7 is: Using the first startup data, after smoothing for 100 seconds, the temperature compensation coefficients A1 = -0.0002 and A2 = 0.0020 were obtained by bringing them into the temperature compensation model.

9. The component-level temperature compensation method for an optical inertial navigation system during startup according to claim 1, characterized in that: After step 7, the following steps are also included: Step 8: Substitute the final temperature compensation model obtained in step 7 into the n sets of data sequences in step 6 to verify the temperature compensation effect.

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