A device and method for measuring accelerometer start-up error

Abstract

This invention provides a device and method for measuring accelerometer startup error, which flexibly tests the startup error of the accelerometer and I / F converter plate individually or in combination, achieving decoupling between the accelerometer zero bias and the I / F converter plate scale coefficient error; it uses a data fitting method to measure the magnitude of startup error over a short period of time, more accurately reflecting the rapid startup zero bias change of the accelerometer; it provides a new method for screening inertial navigation system (INS) instruments; and it provides data basis for INS alignment error analysis, enabling more accurate INS alignment error calculation.

Description

Technical Field

[0001] This invention relates to the field of inertial navigation technology, and in particular to a device and method for measuring accelerometer startup error. Background Technology

[0002] An accelerometer is an acceleration sensor widely used in strapdown inertial navigation systems (INS). The INS autonomously aligns itself based on information such as angular velocity measured by a gyroscope and acceleration measured by an accelerometer, providing essential initial attitude angles and azimuth references for navigation calculations. Reducing INS alignment time and improving alignment accuracy play a crucial role in enhancing the system's rapid response capability.

[0003] Inertial navigation systems (INS) experience complex internal temperature field changes within a short period after power-on. As a core inertial device, the accelerometer's zero-bias error changes significantly after power-on due to inherent factors such as its material properties and structural composition. This severely affects the rapid alignment accuracy of high-precision INS. Designing a device and method for measuring accelerometer startup error is of crucial significance for improving the rapid alignment accuracy of INS. Summary of the Invention

[0004] The present invention aims to provide a measuring device and method for accelerometer startup error that overcomes or at least partially solves the above-mentioned 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 measuring device for accelerometer startup error, comprising: a first power module, a second power module, a data acquisition unit, an automatic power-on device, and a test computer;

[0007] The first power module is electrically connected to the accelerometer and is used to turn the accelerometer on and off.

[0008] The second power module is electrically connected to the I / F conversion board and is used to power on and off the I / F conversion board;

[0009] The data acquisition unit is electrically connected to the I / F conversion board and is used to receive the pulse signal generated by the I / F conversion board after acquiring the accelerometer current signal;

[0010] The automatic power-on device is electrically connected to the first power module and the second power module, and is used to obtain power input through an external power source and to power on the first power module and the second power module respectively.

[0011] The test computer is electrically connected to the data acquisition unit and the automatic power-on device. It is used to control the second power module to operate for a first preset time after the automatic power-on device has been activated for that time. Then, in both horizontal and vertical installation states of the accelerometer, the computer controls the first power module to operate at regular intervals. The data acquisition unit collects the accelerometer's startup error. The collected short-time data is integrated over a second preset time to obtain a sequence of velocity data. This sequence is then fitted with a quadratic curve over time, with the coefficient of the quadratic term representing the accelerometer's zero-bias rate of change.

[0012] The test computer is also used to control the first power module to work for a third preset time through the automatic power-on device, and then, in the vertically installed state of the accelerometer, to control the second power module to work at a time through the automatic power-on device, and to collect the start-up error of the I / F conversion board scale coefficient through the data acquisition unit.

[0013] The test computer is also used to control the first power module and the second power module to be powered on and off simultaneously through the automatic power-on device, and to collect the startup error of the combination of the accelerometer and the I / F conversion board through the data acquisition unit.

[0014] The test computer is also used to control the second power module to work for a first preset time through the automatic power-on device, and then, under different tilt conditions of the accelerometer, control the first power module to work at regular intervals through the automatic power-on device, and collect the startup error of the accelerometer through the data acquisition unit.

[0015] The first preset duration is 2 hours, the second preset duration is 1 second, and the third preset duration is 2 hours.

[0016] Another aspect of the present invention provides a method for measuring accelerometer startup error, comprising:

[0017] Set up the accelerometer start-up error measuring device as described above, and horizontally install and fix the accelerometer on the test platform of the isolated foundation;

[0018] The test computer controls the second power module to work for a first preset time through the automatic power-on device, so that the I / F conversion board remains in a stable working state and the I / F conversion board is kept powered on.

[0019] The test computer controls the first power module to work at regular intervals through the automatic power-on device, and collects the startup error of the accelerometer through the data acquisition unit;

[0020] The test computer integrates the collected short-time data according to a second preset duration to obtain a sequence of velocity data. The sequence is then fitted with a quadratic curve over time, with the coefficient of the quadratic term being the zero-bias rate of change of the accelerometer.

[0021] The methods also include:

[0022] After the test computer controls the first power module to work for a third preset time through the automatic power-on device, in the vertically installed state of the accelerometer, it controls the second power module to work at a time through the automatic power-on device, and collects the start-up error of the I / F conversion board scale coefficient through the data acquisition unit.

[0023] The methods also include:

[0024] The test computer controls the first power module and the second power module to be powered on and off simultaneously through the automatic power-on device, and collects the startup error of the combination of the accelerometer and the I / F conversion board through the data acquisition unit.

[0025] The methods also include:

[0026] After the test computer controls the second power module to work for a first preset time through the automatic power-on device, it controls the first power module to work at regular intervals under different tilt conditions of the accelerometer through the automatic power-on device, and collects the start-up error of the accelerometer through the data acquisition unit.

[0027] The first preset duration is 2 hours, the second preset duration is 1 second, and the third preset duration is 2 hours.

[0028] Therefore, the accelerometer startup error measurement device and method provided by the present invention, which uses data fitting method to calculate the startup error in a short period of time, more accurately reflects the accelerometer startup error. Attached Figure Description

[0029] 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.

[0030] Figure 1 This is a schematic diagram of the structure of the accelerometer startup error measuring device provided in an embodiment of the present invention;

[0031] Figure 2 This is a schematic diagram illustrating a comparison of accelerometer data processing results provided in an embodiment of the present invention.

[0032] Figure 3 A flowchart of a method for measuring accelerometer startup error provided in an embodiment of the present invention. Detailed Implementation

[0033] 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.

[0034] Figure 1 A schematic diagram of the accelerometer startup error measuring device provided in an embodiment of the present invention is shown. See also: Figure 1 The accelerometer startup error measuring device provided in this embodiment of the invention includes: a first power module, a second power module, a data acquisition unit, an automatic power-on device, and a test computer;

[0035] The first power module is electrically connected to the accelerometer and is used to turn the accelerometer on and off.

[0036] The second power module is electrically connected to the I / F conversion board and is used to power on and off the I / F conversion board.

[0037] The data acquisition unit is electrically connected to the I / F conversion board and is used to receive the pulse signal generated by the I / F conversion board after acquiring the accelerometer current signal.

[0038] The automatic power-on device is electrically connected to the first power module and the second power module, and is used to obtain power input through an external power source and to power on the first power module and the second power module respectively.

[0039] The test computer is electrically connected to the data acquisition unit and the automatic power-on device. After the second power module is controlled to work for a first preset time by the automatic power-on device, the first power module is controlled to work at regular intervals in both horizontal and vertical installation states of the accelerometer. The data acquisition unit collects the startup error of the accelerometer. The short-time data collected is integrated according to the second preset time to obtain a sequence of velocity data. The sequence is then fitted with a quadratic curve to time, and the coefficient of the quadratic term is the zero bias rate of change of the accelerometer.

[0040] Specifically, the output of the accelerometer used in this invention is a current signal that is approximately linearly related to the input acceleration. After a pulse signal is generated using an I / F conversion board, it is acquired by the inertial navigation system's data acquisition unit to form acceleration information. Therefore, the startup error of the inertial navigation system accelerometer actually includes the startup error of the accelerometer itself and the calibration coefficient error of the I / F conversion board, both of which change with the startup time.

[0041] To measure the startup error of the accelerometer, this invention designs as follows: Figure 1 The measuring device shown uses a data fitting method to calculate the startup error over a short period of time, thereby decoupling the accelerometer zero bias error and the I / F conversion plate scale coefficient error, and can accurately reflect the rapid startup zero bias change of the accelerometer.

[0042] As an optional implementation of this invention, the first preset duration is 2 hours and the second preset duration is 1 second.

[0043] In practical implementation, this invention is based on the actual working conditions of using an inertial accelerometer and an I / F conversion board in combination. It designs the measurement device to achieve error decoupling and proposes a new data fitting and processing method to address the resolution problem of the I / F conversion board, thereby obtaining a more accurate accelerometer startup error.

[0044] The test computer runs a program to control the switching status of the automatic power-on device, and controls the power input and output of power modules 1 and 2, thereby enabling the accelerometer and I / F conversion board to perform independent power-on and power-off operation modes according to the program settings. The I / F conversion board converts the accelerometer current signal into a pulse signal, which is then acquired at a high frequency by the data acquisition unit, converted into a digital signal, and sent back to the test computer via the serial port, thus completing the accelerometer data acquisition.

[0045] This invention primarily establishes a method for testing the startup error of an accelerometer by controlling the timing of power-on and power-off. Considering the variation in calibration coefficient error on the I / F conversion board after power-on with the temperature of its electronic components, the I / F conversion board must be kept in a stable operating state when testing the accelerometer startup error; that is, the timing of power-on and power-off must be controlled. Figure 1 The power module 2 first works for 2 hours, and then, in both horizontal and vertical installation states of the accelerometer, the power module 1 is controlled to work at regular intervals. The data collected at this time reflects the starting error of the accelerometer itself.

[0046] This invention designs a data fitting method to process short-time data. Taking 80s of data as an example, integration is performed second by second to obtain a sequence of 80 velocity data points. This sequence is then fitted with a quadratic curve over time, with the coefficients of the quadratic term representing the accelerometer's zero-bias rate of change. Compared to the traditional method of obtaining a trend term through ten-second smoothing, this method mitigates the time truncation error caused by the I / F conversion board resolution, and the depicted zero-bias rate of change better reflects the zero-bias changes over a short period of time, as shown in the attached figure. Figure 2 As shown.

[0047] As an optional embodiment of the present invention, the test computer is also used to control the first power module to work for a third preset time by the automatic power-on device, and then, in the vertical installation state of the accelerometer, control the second power module to work at a time by the automatic power-on device, and collect the start-up error of the I / F conversion board scale coefficient by the data acquisition unit.

[0048] As another optional embodiment of the present invention, the test computer is also used to control the first power module and the second power module to be powered on and off simultaneously through the automatic power-on device, and to collect the startup error of the combination of the accelerometer and the I / F conversion board through the data acquisition unit.

[0049] As another optional embodiment of the present invention, the test computer is also used to control the second power module to work for a first preset time through the automatic power-on device, and then, under different tilt conditions of the accelerometer, control the first power module to work at regular intervals through the automatic power-on device, and collect the start-up error of the accelerometer through the data acquisition unit.

[0050] Therefore, the accelerometer startup error measurement device provided in this embodiment of the invention can flexibly perform individual or combined tests on the startup error of the accelerometer and I / F conversion board, providing a new method for screening inertial navigation system instruments.

[0051] As an optional implementation of this invention, the first preset duration is 2 hours, the second preset duration is 1 second, and the third preset duration is 2 hours.

[0052] In practice, the accelerometer is installed vertically, and the control unit is attached. Figure 1 The power module 1 operates for 2 hours initially, after which the accelerometer outputs a stable current signal, equivalent to a high-precision constant current source. This controls the power module 2 to operate at regular intervals. The data collected during this time reflects the startup error of the I / F conversion board's scale coefficient. The control module 2... Figure 1 The power modules 1 and 2 are powered on and off simultaneously. The data collected at this time reflects the startup error of the combination of the accelerometer and the I / F conversion board.

[0053] Of course, the data fitting method designed in this invention processes short-time data, including short-time data obtained under the different conditions described above.

[0054] Therefore, the accelerometer startup error measurement device provided in this embodiment of the invention can flexibly test the startup errors of the accelerometer and the I / F conversion board individually or in combination, realizing the decoupling function of accelerometer zero bias and I / F conversion board scale coefficient error; it uses a data fitting method to measure the magnitude of startup error in a short period of time, more accurately reflecting the rapid startup zero bias change of the accelerometer; it provides a new method for screening inertial navigation system (INS) instruments; and it provides data basis for INS alignment error analysis, enabling more accurate INS alignment error calculation.

[0055] Figure 3 A flowchart of a method for measuring accelerometer startup error according to an embodiment of the present invention is shown. This method applies the aforementioned apparatus. The following is only a brief description of the flowchart of the method for measuring accelerometer startup error. For other matters not covered herein, please refer to the relevant descriptions in the above-described apparatus for measuring accelerometer startup error. Figure 3 The method for measuring accelerometer startup error provided in this embodiment of the invention includes:

[0056] S1, set up the accelerometer start-up error measuring device as described above, and horizontally install and fix the accelerometer on the test platform of the isolated foundation;

[0057] S2, the test computer controls the second power module to work for a first preset time through the automatic power-on device, so that the I / F conversion board can maintain a stable working state and keep the I / F conversion board powered on continuously;

[0058] S3, the test computer controls the first power module to work at a time through the automatic power-on device, and collects the accelerometer's startup error through the data acquisition unit;

[0059] S4, the test computer integrates the short-time data collected according to the second preset duration to obtain a sequence of velocity data, and performs quadratic curve fitting on the sequence and time, with the coefficient of the quadratic term being the zero bias rate of change of the accelerometer.

[0060] As an optional embodiment of the present invention, the method for measuring the accelerometer startup error provided in the present invention further includes: after the test computer controls the first power module to work for a third preset time through the automatic power-on device, the second power module is controlled to work at a time through the automatic power-on device in the vertical installation state of the accelerometer, and the startup error of the I / F conversion board scale coefficient is collected through the data acquisition unit.

[0061] As an optional embodiment of the present invention, the method for measuring the accelerometer startup error provided in the present invention further includes: a test computer controlling the first power module and the second power module to be powered on and off simultaneously through an automatic power-on device, and collecting the startup error of the accelerometer and the I / F conversion board combination through a data acquisition unit.

[0062] As an optional embodiment of the present invention, the method for measuring the accelerometer startup error provided in the present invention further includes: after the test computer controls the second power module to work for a first preset time through the automatic power-on device, under different tilt conditions of the accelerometer, the first power module is controlled to work at regular intervals through the automatic power-on device, and the startup error of the accelerometer is collected through the data acquisition unit.

[0063] As an optional implementation of this invention, the first preset duration is 2 hours, the second preset duration is 1 second, and the third preset duration is 2 hours.

[0064] In practical implementation, taking the starting error of the accelerometer under horizontal conditions as an example, combined with the attached... Figure 1 The implementation steps of the accelerometer startup error measurement method of the present invention will be further explained.

[0065] (1) Install the accelerometer horizontally on the test platform of the isolated foundation, according to the attached... Figure 1 Connect the measuring device and let it stand.

[0066] (2) Design and run a control program to power on the I / F conversion board for 2 hours and maintain a stable working state. After that, the I / F conversion board is not powered on until the test is completed.

[0067] (3) The accelerometer is powered on and the data acquisition host computer software of the test computer is started to receive serial port data from the data acquisition unit.

[0068] (4) After the accelerometer is powered on and data is collected for a period of time, the accelerometer is powered off. The accelerometer is powered on and off multiple times as needed, and multiple sets of accelerometer start-up error data are collected. The test ends and the data is analyzed.

[0069] By changing the installation method of the accelerometer, the zero-bias start-up error of the accelerometer under different tilt conditions can be measured; the operating program can be designed to control the power-on and power-off timing of the accelerometer and the I / F conversion board, and the start-up error of the accelerometer zero bias and the I / F conversion board scale coefficient can be flexibly tested individually or in combination.

[0070] Therefore, the accelerometer startup error measurement method provided in this invention embodiment allows for flexible individual or combined testing of the startup errors of the accelerometer and I / F conversion board, achieving decoupling between the accelerometer zero bias and the I / F conversion board scale coefficient error; the data fitting method measures the magnitude of startup error over a short period, more accurately reflecting the rapid startup zero bias change of the accelerometer; it provides a new method for inertial navigation system (INS) instrument screening; and it provides data support for INS alignment error analysis, enabling more accurate INS alignment error calculation.

[0071] 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 device for measuring an acceleration meter start-up error, characterized in that include: The system comprises a first power module, a second power module, a data acquisition unit, an automatic power-on device, and a test computer. The first power module is electrically connected to the accelerometer and is used to turn the accelerometer on and off. The second power module is electrically connected to the I / F conversion board and is used to power on and off the I / F conversion board; The data acquisition unit is electrically connected to the I / F conversion board and is used to receive the pulse signal generated by the I / F conversion board after acquiring the accelerometer current signal; The automatic power-on device is electrically connected to the first power module and the second power module, and is used to obtain power input through an external power source and to power on the first power module and the second power module respectively. The test computer is electrically connected to the data acquisition unit and the automatic power-on device. It is used to control the second power module to operate for a first preset time after the automatic power-on device has been activated for that time. Then, in both horizontal and vertical installation states of the accelerometer, the computer controls the first power module to operate at regular intervals. The data acquisition unit collects the accelerometer's startup error. The collected short-time data is integrated over a second preset time to obtain a sequence of velocity data. This sequence is then fitted with a quadratic curve over time, with the coefficient of the quadratic term representing the accelerometer's zero-bias rate of change.

2. The apparatus of claim 1, wherein, The test computer is also used to control the first power module to work for a third preset time through the automatic power-on device, and then, in the vertically installed state of the accelerometer, to control the second power module to work at a time through the automatic power-on device, and to collect the start-up error of the I / F conversion board scale coefficient through the data acquisition unit.

3. The apparatus according to claim 2, characterized in that, The test computer is also used to control the first power module and the second power module to be powered on and off simultaneously through the automatic power-on device, and to collect the startup error of the combination of the accelerometer and the I / F conversion board through the data acquisition unit.

4. The apparatus according to claim 3, characterized in that, The test computer is also used to control the second power module to work for a first preset time through the automatic power-on device, and then, under different tilt conditions of the accelerometer, control the first power module to work at regular intervals through the automatic power-on device, and collect the startup error of the accelerometer through the data acquisition unit.

5. The apparatus according to claim 4, characterized in that, The first preset duration is 2 hours, the second preset duration is 1 second, and the third preset duration is 2 hours.

6. A method for measuring the starting error of an accelerometer, characterized in that, include: The device for measuring the accelerometer startup error as described in any one of claims 1 to 5 is provided, and the accelerometer is horizontally installed and fixed on the test platform of the isolated foundation. The test computer controls the second power module to work for a first preset time through the automatic power-on device, so that the I / F conversion board remains in a stable working state and the I / F conversion board is kept powered on. The test computer controls the first power module to work at regular intervals through the automatic power-on device, and collects the startup error of the accelerometer through the data acquisition unit; The test computer integrates the collected short-time data according to a second preset duration to obtain a sequence of velocity data. The sequence is then fitted with a quadratic curve over time, with the coefficient of the quadratic term being the zero-bias rate of change of the accelerometer.

7. The method according to claim 6, characterized in that, Also includes: After the test computer controls the first power module to work for a third preset time through the automatic power-on device, in the vertically installed state of the accelerometer, it controls the second power module to work at a time through the automatic power-on device, and collects the start-up error of the I / F conversion board scale coefficient through the data acquisition unit.

8. The method according to claim 7, characterized in that, Also includes: The test computer controls the first power module and the second power module to be powered on and off simultaneously through the automatic power-on device, and collects the startup error of the combination of the accelerometer and the I / F conversion board through the data acquisition unit.

9. The method according to claim 8, characterized in that, Also includes: After the test computer controls the second power module to work for a first preset time through the automatic power-on device, it controls the first power module to work at regular intervals under different tilt conditions of the accelerometer through the automatic power-on device, and collects the start-up error of the accelerometer through the data acquisition unit.

10. The method according to claim 9, characterized in that, The first preset duration is 2 hours, the second preset duration is 1 second, and the third preset duration is 2 hours.

Images