Automatic inertial measurement unit calibration test system and method

Abstract

The invention belongs to the technical field of calibration test of inertial measurement units, and particularly discloses an automatic inertial measurement unit calibration test system and method, and the method comprises the following steps: fixing an inertial measurement unit to be tested on a triaxial rate turntable in a high and low temperature test box through a tool; controlling the three-axis rate turntable and the incubator to carry out multiple groups of rate and position point tests at different temperature points, and collecting sensor data of the inertial measurement unit; carrying out mean value calculation on sensor data of the inertial measurement unit, and calculating parameters of the inertial measurement unit by utilizing integrated parameter calculation and online injection software according to the mean value; the parameters of the inertial measurement unit are injected through integrated parameter calculation and online injection software, and automatic inertial measurement unit calibration testing is completed. According to the method, the problems that in the prior art, the dependence on personnel in inertial measurement unit testing and calibration is too high, the labor intensity is increased due to traditional offline upgrading, and the product damage risk is high are solved.

Description

Technical Field

[0001] The invention belongs to the technical field of calibration and testing of inertial measurement units, and in particular relates to an automated inertial measurement unit calibration and testing system and method. Background Art

[0002] With the improvement of accuracy and reduction of cost of inertial devices such as fiber optic gyroscopes and MEMS gyroscopes, inertial measurement units are increasingly widely used in weapons manufacturing, industrial manufacturing and consumer electronics, and their production scale is getting larger and larger. With the reduction of device costs and the expansion of application scale, the calibration and testing of inertial measurement units have gradually become a bottleneck restricting their cost reduction and application. Conventional inertial measurement unit calibration tests separate testing and data processing, that is, data acquisition and recording are performed first, and then the data is exported for manual processing, or imported into Matlab and Excel for calculation, which is inefficient. At the same time, the correction parameters of conventional inertial measurement units are all parameter values ​​of calculated linear or nonlinear functions, which do not have intuitive physical meanings, which brings difficulties to parameter inspection and verification.

[0003] When the production quantity of inertial measurement units increases, a large amount of data will cause confusion in the production process, resulting in product compensation errors and ultimately leading to reduced efficiency and increased production costs. Summary of the invention

[0004] The purpose of the present invention is to solve the problems of excessive reliance on personnel in the prior art for inertial measurement unit testing and calibration, increased labor intensity caused by traditional offline upgrades, and high risk of product damage, and propose an automated inertial measurement unit calibration test system and method.

[0005] The technical solution of the present invention is as follows: in the first aspect, an automated inertial measurement unit calibration test system includes an industrial control computer, a high and low temperature test chamber, a serial port acquisition card and a three-axis rate turntable; The three-axis rate turntable is located inside the high and low temperature test box; the serial port acquisition card is respectively connected to the three-axis rate turntable, the high and low temperature test box and the industrial control computer for communication.

[0006] In a second aspect, an automated inertial measurement unit calibration test method comprises the following steps: S1. Fix the inertial measurement unit to be tested on the three-axis rate turntable in the high and low temperature test chamber through the tooling; S2. Send operation control instructions to the three-axis rate turntable and the high and low temperature test chamber through the integrated equipment control and data acquisition software on the industrial computer, perform multiple groups of rate and position point tests, and collect sensor data of the inertial measurement unit at different temperature points; S3. Calculate the average value of the sensor data of each inertial measurement unit, and calculate the parameters of the inertial measurement unit using the integrated parameter calculation and online injection software on the industrial computer according to the average value; S4. The parameters of the inertial measurement unit are injected through the integrated parameter calculation and online injection software on the industrial computer to complete the automated inertial measurement unit calibration test.

[0007] Preferably, the temperature points in step S2 include -55°C, -40°C, -25°C, -10°C, +5°C, +25°C, +40°C, +55°C and +70°C.

[0008] Preferably, the parameters of the inertial measurement unit in step S3 include temperature parameters, three-axis gyro zero bias, three-axis gyro positive scaling factor, three-axis gyro negative scaling factor, three-axis gyro axis misalignment parameter, three-axis added zero bias, three-axis added positive scaling factor, three-axis added negative scaling factor and three-axis added axis misalignment parameter.

[0009] Preferably, the calculation formula of the temperature parameter is:

[0010] in, Indicates The average temperature at each temperature point, Indicates Temperature point The average temperature at each location.

[0011] Preferably, the calculation formula of the three-axis gyro zero bias is:

[0012] in, Indicates Temperature point The gyroscopic zero bias of the axis, Indicates Temperature point The gyroscopic zero bias of the axis, Indicates Temperature point The gyroscopic zero bias of the axis, Indicates Temperature point Locations The gyro mean of the axis, Indicates Temperature point Locations The gyro mean of the axis, Indicates Temperature point Locations Gyro mean of the axis; The calculation formula of the positive scale factor of the three-axis gyroscope is:

[0013] in, Indicates Temperature point The gyro positive scale factor of the axis, Indicates Temperature point The gyro positive scale factor of the axis, Indicates Temperature point The gyro positive scale factor of the axis; The calculation formula of the negative scale factor of the three-axis gyroscope is:

[0014] in, Indicates Temperature point The negative gyro scale factor of the axis, Indicates Temperature point The negative gyro scale factor of the axis, Indicates Temperature point Negative gyro scale factor of the axis; The calculation formula of the three-axis gyroscope axis misalignment parameter is:

[0015] in, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis.

[0016] Preferably, the calculation formula of the three-axis added zero bias is:

[0017] in, Indicates Temperature point Additive zero offset of the axis, Indicates Temperature point Additive zero offset of the axis, Indicates Temperature point Additive zero offset of the axis, Indicates Temperature point Locations The summed mean of the axis, Indicates Temperature point Locations The summed mean of the axis, Indicates Temperature point Locations The summed mean of the axis; The calculation formula of the three-axis plus positive scale factor is:

[0018] in, Indicates Temperature point The added positive scale factor of the axis, Indicates Temperature point The added positive scale factor of the axis, Indicates Temperature point The added positive scale factor of the axis, is the acceleration due to gravity; The calculation formula of the three-axis plus negative scale factor is:

[0019] in, Indicates Temperature point The negative scaling factor of the axis, Indicates Temperature point The negative scaling factor of the axis, Indicates Temperature point Addition of negative scale factor of the axis; The calculation formula of the three-axis plus axis misalignment parameter is:

[0020] in, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis.

[0021] Preferably, the step S4 is specifically as follows: open the integrated parameter calculation and online injection software, set the path to the data storage location of the currently compensated inertial measurement unit, click parameter write to complete the parameter annotation, and the injection time and product number information will be recorded during the parameter annotation process to complete the automated inertial measurement unit calibration test.

[0022] Preferably, when the parameters of the inertial measurement unit are updated in step S4, a combined communication mode of time domain gating and command handshake is adopted.

[0023] The beneficial effects of the present invention are: 1. The method proposed in the present invention achieves full automation of the entire process from inertial measurement unit testing, parameter calculation and parameter injection, reduces human intervention, reduces the risk of human error and the workload of personnel, and improves the efficiency of testing the inertial measurement unit; 2. The present invention provides a new, feasible and clear calibration test method for high-precision inertial measurement units under full temperature conditions, namely, 30 static and dynamic test methods, using 30 point data in three-dimensional inertial space, to calculate the full-temperature zero bias, scale factor and respective axis misalignment parameters of the three-axis fiber optic gyroscope and the three-axis accelerometer; 3. The present invention provides a new, full-parameter parameter annotation method and data storage method for temperature compensation, zero bias correction and axis misalignment compensation of an inertial measurement unit, which can intuitively display sensor parameters and greatly facilitate compensation and data verification of the inertial measurement unit under full temperature conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Figure 1 The figure shows a structural diagram of an automated inertial measurement unit calibration and testing system provided in Example 1 of the present invention.

[0025] Figure 2 Shown is a flow chart of an automated inertial measurement unit calibration test method provided in Example 2 of the present invention.

[0026] Figure 3 The figure shows a flow chart of injecting parameters of an inertial measurement unit by means of integrated parameter calculation and online injection software on an industrial control computer provided in Example 2 of the present invention.

[0027] Figure numerals: 1. Industrial computer; 2. High and low temperature test chamber; 3. Serial acquisition card; 4. Three-axis rate turntable; 5. USB device. DETAILED DESCRIPTION

[0028] Now, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings. It should be understood that the embodiments shown and described in the accompanying drawings are only exemplary and are intended to explain the principles and spirit of the present invention, rather than to limit the scope of the present invention.

[0029] Embodiment 1: An automated inertial measurement unit calibration test system, such as Figure 1 As shown, it includes an industrial control computer 1, a high and low temperature test chamber 2, a serial port acquisition card 3 and a three-axis rate turntable 4; The three-axis rate turntable 4 is located inside the high and low temperature test box 2; the serial port acquisition card 3 is respectively connected to the three-axis rate turntable 4, the high and low temperature test box 2 and the industrial control computer 1 for communication.

[0030] In this embodiment, the inertial measurement unit to be tested is fixed on the three-axis rate turntable 4, the industrial control computer 1 sends an operation control instruction to the serial port acquisition card 3, and the serial port acquisition card 3 transmits the operation control instruction to the high and low temperature test box 2 and the three-axis rate turntable 4 through the RS232 bus; the high and low temperature test box 2 receives the operation control instruction and provides different temperatures for the calibration test of the inertial measurement unit; after receiving the operation control instruction, the three-axis rate turntable 4 performs a 30-position test to obtain sensor data of the inertial measurement unit at different temperatures and different positions, and transmits the sensor data of the inertial measurement unit at different temperatures and different positions to the serial port acquisition card 3 through the RS422 serial bus, and the serial port acquisition card 3 transmits the sensor data to the industrial control computer 1 through the USB device 5, and the integrated device control and data acquisition software on the industrial control computer 1 performs data processing to calculate the parameters of the inertial measurement unit, and then the integrated parameter calculation and online injection software on the industrial control computer 1 is used to perform parameter injection.

[0031] Embodiment 2: Based on Example 1, this embodiment provides an automated inertial measurement unit calibration test method, such as Figure 2 As shown, the following steps are included: S1. The inertial measurement unit to be tested is fixed on the three-axis rate turntable 4 in the high and low temperature test chamber 2 through the tooling; S2. The integrated equipment control and data acquisition software on the industrial computer 1 sends operation control instructions to the three-axis rate turntable 4 and the high and low temperature test chamber 2, performs multiple groups of rate and position point tests, and collects sensor data of the inertial measurement unit at different temperature points; In this embodiment, a total of 30 groups of tests including rate tests and position tests are performed, referred to as 30 position tests, and the temperature points include -55°C, -40°C, -25°C, -10°C, +5°C, +25°C, +40°C, +55°C and +70°C; the actions and corresponding times of the three-axis rate turntable 4 at each temperature point are shown in Table 1; Table 1 Three-axis speed turntable motion and time

[0032]

[0033] S3. Calculate the mean value of the sensor data of each inertial measurement unit at 30 positions, and calculate the parameters of the inertial measurement unit according to the mean value using the integrated parameter calculation and online injection software on the industrial control computer 1; after the calculation is completed, the parameters of the inertial measurement unit are stored in the Cpsfile.txt file under the folder named with the inertial measurement unit number through the integrated parameter calculation and online injection software; the parameters of the inertial measurement unit include temperature parameters, three-axis gyro zero bias, three-axis gyro positive scaling factor, three-axis gyro negative scaling factor, three-axis gyro axis misalignment parameter, three-axis plus zero bias, three-axis plus positive scaling factor, three-axis plus negative scaling factor and three-axis plus axis misalignment parameter; the mean value of the sensor data of each inertial measurement unit is shown in Table 2; Table 2 Sensor data mean value list

[0034] In this embodiment, the calculation formula of the temperature parameter is:

[0035] in, Indicates The average temperature at each temperature point, Indicates Temperature point The average temperature at each location.

[0036] In this embodiment, the calculation formula of the three-axis gyro zero bias is:

[0037] in, Indicates Temperature point The gyroscopic zero bias of the axis, Indicates Temperature point The gyroscopic zero bias of the axis, Indicates Temperature point The gyroscopic zero bias of the axis, Indicates Temperature point Locations The gyro mean of the axis, Indicates Temperature point Locations The gyro mean of the axis, Indicates Temperature point Locations Gyro mean of the axis; The calculation formula of the positive scale factor of the three-axis gyroscope is:

[0038] in, Indicates Temperature point The gyro positive scale factor of the axis, Indicates Temperature point The gyro positive scale factor of the axis, Indicates Temperature point The gyro positive scale factor of the axis; The calculation formula of the negative scale factor of the three-axis gyroscope is:

[0039] in, Indicates Temperature point The negative gyro scale factor of the axis, Indicates Temperature point The negative gyro scale factor of the axis, Indicates Temperature point Negative gyro scale factor of the axis; The calculation formula of the three-axis gyroscope axis misalignment parameter is:

[0040] in, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis.

[0041] In this embodiment, the calculation formula of the three-axis added zero bias is:

[0042] in, Indicates Temperature point Additive zero offset of the axis, Indicates Temperature point Additive zero offset of the axis, Indicates Temperature point Additive zero offset of the axis, Indicates Temperature point Locations The summed mean of the axis, Indicates Temperature point Locations The summed mean of the axis, Indicates Temperature point Locations The summed mean of the axes; The calculation formula of the three-axis plus positive scale factor is:

[0043] in, Indicates Temperature point The added positive scale factor of the axis, Indicates Temperature point The added positive scale factor of the axis, Indicates Temperature point The added positive scale factor of the axis, is the acceleration due to gravity; The calculation formula of the three-axis plus negative scale factor is:

[0044] in, Indicates Temperature point The negative scaling factor of the axis, Indicates Temperature point The negative scaling factor of the axis, Indicates Temperature point Addition of negative scale factor of the axis; The calculation formula of the three-axis plus axis misalignment parameter is:

[0045] in, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis.

[0046] S4. The parameters of the inertial measurement unit are annotated through the integrated parameter calculation and online injection software on the industrial control computer 1. Specifically, open the integrated parameter calculation and online injection software, set the path to the data storage location of the currently compensated inertial measurement unit, and click parameter write to complete the parameter annotation. During the parameter annotation process, the injection time and product number information will be recorded to complete the automated inertial measurement unit calibration test. The integrated parameter calculation and online injection software has the function of parameter reading back and report generation. It can read back the compensation data of the inertial measurement unit and generate a report as a key parameter of the product for recording. The parameter recording format is shown in Table 3.

[0047] Table 3 Inertial measurement unit parameter recording format

[0048] In this embodiment, if Figure 3As shown, when the parameters of the inertial measurement unit are updated in step S4, a combined communication mode of time domain gating and command handshake is adopted. The inertial measurement unit responds to the external parameter upgrade command within 1s after power-on, and does not respond to the external parameter upgrade command after 1s. If the handshake command is received within 1s, it enters the waiting mode, selects and clicks to select the compensation parameter TXT file, and clicks the parameter update to complete the upgrade. At the same time, the upgrade method has a parameter readback function to facilitate the confirmation of the product status.

[0049] Those skilled in the art will appreciate that the embodiments described herein are intended to help readers understand the principles of the present invention, and should be understood that the protection scope of the present invention is not limited to such specific statements and embodiments. Those skilled in the art can make various other specific variations and combinations that do not deviate from the essence of the present invention based on the technical revelations disclosed by the present invention, and these variations and combinations are still within the protection scope of the present invention.

Claims

1. An automated inertial measurement unit calibration test system, characterized in that: It includes an industrial control computer (1), a high and low temperature test chamber (2), a serial port acquisition card (3) and a three-axis rate turntable (4); The three-axis rate turntable (4) is located inside the high and low temperature test chamber (2); the serial port acquisition card (3) is respectively connected to the three-axis rate turntable (4), the high and low temperature test chamber (2) and the industrial control computer (1) for communication.

2. An automated inertial measurement unit calibration test method, characterized in that: The following steps are involved: S1. The inertial measurement unit to be tested is fixed on the three-axis rate turntable (4) in the high and low temperature test chamber (2) through the tooling; S2. Sending operation control instructions to the three-axis rate turntable (4) and the high and low temperature test chamber (2) through the integrated equipment control and data acquisition software on the industrial computer (1), performing multiple groups of rate and position point tests, and collecting sensor data of the inertial measurement unit at different temperature points; S3. Calculate the average of the sensor data of each inertial measurement unit, and calculate the parameters of the inertial measurement unit using the integrated parameter calculation and online injection software on the industrial computer (1) according to the average; S4. The parameters of the inertial measurement unit are injected through the integrated parameter calculation and online injection software on the industrial control computer (1) to complete the automated inertial measurement unit calibration test.

3. The automated inertial measurement unit calibration test method according to claim 2, characterized in that: The temperature points in step S2 include -55°C, -40°C, -25°C, -10°C, +5°C, +25°C, +40°C, +55°C and +70°C.

4. The automated inertial measurement unit calibration test method according to claim 3, characterized in that: The parameters of the inertial measurement unit in step S3 include temperature parameters, three-axis gyro zero bias, three-axis gyro positive scaling factor, three-axis gyro negative scaling factor, three-axis gyro axis misalignment parameter, three-axis added zero bias, three-axis added positive scaling factor, three-axis added negative scaling factor and three-axis added axis misalignment parameter.

5. The automated inertial measurement unit calibration test method according to claim 4, characterized in that: The calculation formula of the temperature parameter is: in, Indicates The average temperature at each temperature point, Indicates Temperature point The average temperature at each location.

6. The automated inertial measurement unit calibration test method according to claim 4, characterized in that: The calculation formula of the three-axis gyro zero bias is: in, Indicates Temperature point The gyroscopic zero bias of the axis, Indicates Temperature point The gyroscopic zero bias of the axis, Indicates Temperature point The gyroscopic zero bias of the axis, Indicates Temperature point Locations The gyro mean of the axis, Indicates Temperature point Locations The gyro mean of the axis, Indicates Temperature point Locations Gyro mean of the axis; The calculation formula of the positive scale factor of the three-axis gyroscope is: in, Indicates Temperature point The gyro positive scale factor of the axis, Indicates Temperature point The gyro positive scale factor of the axis, Indicates Temperature point The gyro positive scale factor of the axis; The calculation formula of the negative scale factor of the three-axis gyroscope is: in, Indicates Temperature point The negative gyro scale factor of the axis, Indicates Temperature point The negative gyro scale factor of the axis, Indicates Temperature point Negative gyro scale factor of the axis; The calculation formula of the three-axis gyroscope axis misalignment parameter is: in, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis.

7. The automated inertial measurement unit calibration test method according to claim 4, characterized in that: The calculation formula of the three-axis added zero bias is: in, Indicates Temperature point Additive zero offset of the axis, Indicates Temperature point Additive zero offset of the axis, Indicates Temperature point Additive zero offset of the axis, Indicates Temperature point Locations The summed mean of the axis, Indicates Temperature point Locations The summed mean of the axis, Indicates Temperature point Locations The summed mean of the axes; The calculation formula of the three-axis plus positive scale factor is: in, Indicates Temperature point The added positive scale factor of the axis, Indicates Temperature point The added positive scale factor of the axis, Indicates Temperature point The added positive scale factor of the axis, is the acceleration due to gravity; The calculation formula of the three-axis plus negative scale factor is: in, Indicates Temperature point The negative scaling factor of the axis, Indicates Temperature point The negative scaling factor of the axis, Indicates Temperature point Additive negative scale factor of the axis; The calculation formula of the three-axis plus axis misalignment parameter is: in, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis, Indicates Temperature point axis gyro coupled to The misalignment angle of the axis.

8. The automated inertial measurement unit calibration test method according to claim 2, characterized in that: The step S4 is specifically as follows: opening the integrated parameter calculation and online injection software, setting the path to the data storage location of the currently compensated inertial measurement unit, clicking parameter write to complete parameter injection, and recording the injection time and product number information during the parameter injection process to complete the automated inertial measurement unit calibration test.

9. The automated inertial measurement unit calibration test method according to claim 2, characterized in that: When the parameters of the inertial measurement unit are updated in step S4, a combined communication mode of time domain gating and command handshake is adopted.

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