A test method for obtaining the cross-axis sensitivity of an accelerometer

Abstract

The present invention discloses a method for testing the cross-axis sensitivity of an accelerometer, which is realized by a dual centrifuge system. The method includes the following steps: First, fix the accelerometer to be tested on the slave centrifuge, zero the slave centrifuge and position it at the zero position, and record the output U0 of the accelerometer to be tested; Next, set the output acceleration of the master centrifuge to a preset value a, start the master centrifuge, and keep the angle of the slave centrifuge at 0°, and record the output U1 of the accelerometer to be tested at this time; Subsequently, the slave centrifuge is respectively positioned at 90°, 180°, and 270°, and the outputs U2, U3, and U4 of the accelerometer to be tested at each position are recorded; Use the formula k o = k1×(U2 - U4) / (U1 - U3) to calculate the cross-axis sensitivity k of the output axis o ; Finally, reinstall the accelerometer, repeat the above steps, and calculate the cross-axis sensitivity k of the pendulum axis p . The method of the present invention can accurately measure the cross-axis sensitivity of the accelerometer, improve the measurement efficiency and accuracy, and is applicable to various high-precision accelerometer test scenarios.

Description

Technical Field

[0001] The present invention belongs to the technical field of accelerometers, and particularly relates to a test method for obtaining the cross-axis sensitivity of an accelerometer. Background Art

[0002] As a key sensor, accelerometers are widely used in commercial electronic devices, industrial automation, aerospace, and military navigation systems to measure the acceleration changes of objects. In the research and development, production, and practical applications of accelerometers, it is crucial to ensure the accuracy and reliability of their performance indicators. These performance indicators include, but are not limited to, zero bias, scale factor, cross-axis sensitivity, and quadratic term coefficient, etc. Among them, the cross-axis sensitivity is particularly critical because it directly affects the response of the accelerometer in the non-sensitive axis direction, thereby affecting the overall measurement accuracy. An ideal accelerometer should only respond to the acceleration changes in its sensitive axis direction. However, in practice, due to factors such as manufacturing processes, material properties, and design structures, the accelerometer will also produce a certain output in the orthogonal direction, namely the so-called cross-axis error. The cross-axis sensitivity is exactly the parameter used to quantify the degree of this error. The lower its value, the smaller the response of the accelerometer in the non-sensitive axis direction and the better the performance.

[0003] Currently, the industry generally adopts a calibration scheme based on a dividing head and a multi-position tilt turntable to measure the cross-axis sensitivity of accelerometers. This scheme realizes a high-precision calibration through a non-linear model and a method of step-by-step linearization of parameters. However, its process is cumbersome, costly, and can only obtain the cross-axis sensitivity value within the acceleration range of ±1g. In addition, the traditional method is limited by the acceleration range provided by the dividing head and cannot comprehensively evaluate the change trend of the cross-axis sensitivity at higher acceleration levels (such as ±10g or ±100g).

[0004] In the prior art, when measuring the cross-axis sensitivity of an accelerometer by the multi-position method, it is necessary to rotate the dividing head to 24 or 36 different positions and calculate the cross-axis sensitivity in combination with the output model of the accelerometer. However, this method has the following two major defects: First, the cross-axis error introduced at ±1g acceleration may be confused with other test errors, and too many position settings significantly increase the test complexity and calculation difficulty; Second, the cross-axis sensitivity measured based on the dividing head is only applicable to the ±1g acceleration input and fails to fully reflect the cross-axis error characteristics in a wider acceleration range. Especially when the external lateral acceleration increases, the non-linear change of the cross-axis sensitivity may have a significant impact on the measurement results.

[0005] In view of the above problems, developing a new calibration method that can efficiently and accurately measure the cross-axis sensitivity of an accelerometer within the full range has become an urgent technical problem to be solved. Summary of the Invention

[0006] The main object of the present invention is to overcome the drawbacks and deficiencies of the prior art, and to provide a test method for obtaining the cross-axis sensitivity of an accelerometer. Through the test method of the present invention, the cross-axis sensitivity under different lateral acceleration inputs can be obtained, and the accuracy of the accelerometer output model can be improved.

[0007] In order to achieve the above object, the present invention adopts the following technical solutions:

[0008] The present invention provides a method for testing the cross-axis sensitivity of an accelerometer, including the following steps:

[0009] S1. Power on the main centrifuge and the slave centrifuge, make the slave centrifuge return to zero and be positioned at the zero position, fix the accelerometer to be tested on the tabletop of the slave centrifuge, power on the accelerometer to be tested, and when the main centrifuge is stationary, position the angle of the slave centrifuge at the zero position, wait for the thermal stable output value of the accelerometer to be tested to be stable, and record the output U of the accelerometer to be tested at this time 0 ;

[0010] S2. Set the output acceleration of the main centrifuge to a preset value a, that is, the acceleration input from the outside, start the main centrifuge, and keep the angle of the slave centrifuge at the zero degree angle, and record the output U of the accelerometer to be tested at this time 1 ;

[0011] S3. While the main centrifuge is continuously rotating, set the slave centrifuge to the position mode and rotate it to the 90° angle, and record the output U of the accelerometer at this time 2 ;

[0012] S4. Continue to keep the main centrifuge rotating, set the slave centrifuge to the position mode and rotate it to the 180° angle, and record the output U of the accelerometer at this time 3 ;

[0013] S5. Still keep the main centrifuge rotating, set the slave centrifuge to the position mode and rotate it to the 270° angle, and record the output U of the accelerometer at this time 4 ;

[0014] S6. According to the cross-axis sensitivity calculation formula k of the accelerometer o =k 1 ×(U 2 -U 4 ) / (U 1 -U 3 ), calculate the cross-axis sensitivity k of the output axis of the accelerometer o ;

[0015] S7. Reinstall the accelerometer under test so that the pendulum axis and input axis of the accelerometer under test are on the installation plane of the centrifuge. Repeat steps S1 - S6, and accordingly calculate the cross-axis sensitivity k of the pendulum axis of the accelerometer. p .

[0016] As a preferred technical solution, in step S1, when the accelerometer under test is fixed to the tabletop of the slave centrifuge, the sensitive axis of the accelerometer under test is located on the line connecting the rotation centers of the master centrifuge and the slave centrifuge, and the sensitive centroid of the accelerometer under test is located at the center of the slave centrifuge.

[0017] As a preferred technical solution, in step S1, the output U of the accelerometer under test 0 The calculation formula is as follows:

[0018] U 0 = k 0 + k p × a p

[0019] Where k 0 is the zero bias of the accelerometer, k p is the cross-axis sensitivity in the direction of the pendulum axis of the accelerometer, and a p is the pendulum axis acceleration.

[0020] As a preferred technical solution, in step S2, the output U of the accelerometer for measurement 1 The calculation formula is as follows:

[0021] U 1 = k 0 + k 1 × a + k 2 × a 2 + k p × a p

[0022] Where k 0 is the zero bias of the accelerometer, a is the externally input acceleration, k 1 is the scale factor of the accelerometer, k 2 is the second-order coefficient of the accelerometer, k p is the cross-axis sensitivity in the direction of the pendulum axis of the accelerometer, and a p is the pendulum axis acceleration.

[0023] As a preferred technical solution, in step S3, the output U of the accelerometer 2 The calculation formula is as follows:

[0024] U 2 = k 0 + k o × a + k p × ap

[0025] Among them, k 0 is the zero bias of the accelerometer, a is the externally input acceleration, and k o is the cross-axis sensitivity of the accelerometer in the output axis direction, and k p is the cross-axis sensitivity of the accelerometer in the pendulum axis direction, and a p is the pendulum axis acceleration.

[0026] As a preferred technical solution, in step S4, the output U of the accelerometer 3 is calculated as follows:

[0027] U 3 = k 0 - k 1 × a + k 2 × a 2 + k p × a p

[0028] Among them, k 0 is the zero bias of the accelerometer, a is the externally input acceleration, and k 1 is the scale factor of the accelerometer, and k 2 is the second-order coefficient of the accelerometer, and k p is the cross-axis sensitivity of the accelerometer in the pendulum axis direction, and a p is the pendulum axis acceleration.

[0029] As a preferred technical solution, in step S5, the output U of the accelerometer 4 is calculated as follows:

[0030] U 4 = k 0 - k o × a + k p × a p

[0031] Among them, k 0 is the zero bias of the accelerometer, a is the externally input acceleration, and k o is the cross-axis sensitivity of the accelerometer in the output axis direction, and k p is the cross-axis sensitivity of the accelerometer in the pendulum axis direction, and a p is the pendulum axis acceleration.

[0032] As a preferred technical solution, the workbench surface of the main centrifuge is parallel to the ground, the rotating shaft of the main centrifuge is perpendicular to the ground, the slave centrifuge is installed on the turntable or the rotating arm of the main centrifuge, and the workbench surface of the slave centrifuge is parallel to the ground, the rotating shaft is parallel to the rotating shaft of the main centrifuge. There are two or more slave centrifuges, which are symmetrically installed on the circular table surface of the speed stabilizing table.

[0033] Compared with the prior art, the present invention has the following advantages and beneficial effects:

[0034] The present invention proposes a new method for testing the cross-axis sensitivity of an accelerometer, which overcomes the limitations of traditional testing means and significantly improves the testing efficiency and accuracy. Specifically, the present invention has the following remarkable advantages:

[0035] 1. Enhanced testing flexibility: By utilizing different rotational positions of a dual centrifuge linear acceleration turntable, the present invention can obtain the cross-axis sensitivity at a series of different acceleration levels, rather than being limited to the traditional ±1g condition. This greatly broadens the testing range and enables the performance evaluation of accelerometers under various working conditions.

[0036] 2. Simplified testing process: The method of the present invention simplifies the testing steps compared with traditional means, reduces the operation complexity and the required time. This not only saves resources but also reduces the testing cost and improves the overall testing efficiency.

[0037] 3. Improved testing accuracy: Based on the theoretical derivation of the accelerometer output model, the present invention constructs an accurate model for calculating the cross-axis sensitivity. This method can more accurately measure the cross-axis sensitivity between the output axis and the pendulum axis of the accelerometer, ensuring the reliability of the test results.

[0038] 4. Facilitated engineering applications: The present invention provides a new solution for the engineering testing of accelerometer performance indicators, which helps to promote the application of accelerometers in fields such as aerospace, automotive industry, and consumer electronics, accelerates the product development cycle, and improves the performance of the final products. Description of the Drawings

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the following will briefly introduce the drawings required for the description of the embodiments. Obviously, the following drawings are only some embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can be obtained based on these drawings.

[0040] Figure 1 Schematic diagram of the principle of the dual centrifuge linear acceleration turntable of the present invention;

[0041] Figure 2 Schematic diagram of the test installation of the accelerometer of the present invention;

[0042] Figure 3 Flowchart of a method for testing the cross-axis sensitivity of an accelerometer according to the present invention.

[0043] Explanation of the reference numerals in the drawings: 1 - main centrifuge; 2 - slave centrifuge; 3 - rotation axis of the main centrifuge. Detailed implementation manners

[0044] In order to enable those skilled in the art of this technology to better understand the solutions of this application, the technical solutions in the embodiments of this application will be clearly and completely described below in conjunction with the accompanying drawings in the embodiments of this application. Obviously, the described embodiments are only a part of the embodiments of this application, rather than all the embodiments. Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without making creative efforts belong to the scope of protection of this application.

[0045] In this application, the mention of "embodiment" means that the specific features, structures or characteristics described in combination with the embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various positions in the specification does not necessarily refer to the same embodiment, nor is it an independent or alternative embodiment that is mutually exclusive with other embodiments. Those skilled in the art will explicitly and implicitly understand that the embodiments described in this application can be combined with other embodiments.

[0046] As certain terms are used in the specification and claims to refer to specific components. Those skilled in the art should understand that hardware manufacturers may use different terms to refer to the same component. The specification and claims do not use the difference in name as a way to distinguish components, but use the difference in function of components as the criterion for distinction. As the term "including" mentioned throughout the specification and claims is an open term, it should be interpreted as "including but not limited to"; "substantially" means that those skilled in the art can solve technical problems within a certain error range and basically achieve technical effects.

[0047] A test method for obtaining the cross-axis sensitivity of an accelerometer provided by the present invention is implemented based on a dual centrifuge linear acceleration turntable. As Figure 1 shown in the schematic diagram of the principle of the dual centrifuge linear acceleration turntable, the dual centrifuge linear acceleration turntable is composed of a main centrifuge 1 and a slave centrifuge 2. The acceleration signal generated by it can be used as an input quantity to calibrate the accelerometer to be calibrated. The workbench surface of the main centrifuge 1 is parallel to the ground, the rotation axis 3 of the main centrifuge is perpendicular to the ground, the slave centrifuge is installed on the turntable or turntable arm of the main centrifuge, and its workbench surface is parallel to the ground, and the rotation axis is parallel to the rotation axis of the main centrifuge. There can be two or more slave centrifuges, which are symmetrically installed on the circular table surface of the speed stabilization table.

[0048] When performing the cross-axis sensitivity test of the accelerometer, the accelerometer to be tested is installed on the workbench surface of the slave centrifuge, so that the sensitive axis of the accelerometer to be calibrated is on the line connecting the centers of the main centrifuge and the slave centrifuge; after the main centrifuge and the slave centrifuge are closed and fixed, the main centrifuge rotates at an angular velocity ω 1 uniformly, generating a certain centrifugal acceleration a. The magnitude of the acceleration a is determined by the angular velocity ω of the main centrifuge1 It is determined by the working radius of the accelerometer that the direction of the acceleration a is from the rotation center of the main centrifuge to the centroid of the sensitive structure of the accelerometer.

[0049] Currently, there are two working modes for the centrifuge. The first mode is the rate mode. While the main centrifuge is rotating, the slave centrifuge rotates at an angular rate ω 2 uniformly, and the rotation of the slave centrifuge changes the direction of the sensitive axis of the accelerometer. The second mode is the position mode, that is, the slave centrifuge is rotated by a certain angle so that there is a fixed angle between the sensitive axis of the accelerometer and the centrifugal acceleration. After fixing the slave centrifuge, the main centrifuge is rotated to generate an acceleration acting on the accelerometer to be calibrated.

[0050] In this embodiment, the output expression of the accelerometer is further elaborated first:

[0051] What the accelerometer senses is acceleration. That is, when there is an external acceleration input, its output will change. The most basic output expression of the accelerometer is:

[0052] U out = k 0 + k 1 ×a i (1)

[0053] Among them, U out is the output of the accelerometer; k 0 is the zero bias of the accelerometer, that is, the output of the accelerometer when there is no acceleration input; k 1 is the scale factor of the accelerometer, that is, the calibration factor, which refers to the ratio of the output of the accelerometer to the acceleration input; a i is the linear acceleration loaded in the direction of the input axis of the accelerometer.

[0054] After considering the cross-acceleration error and nonlinearity of the accelerometer, its output expression is:

[0055] U out = k 0 + k 1 ×a i +k 2 ×a i 2 + k o ×a 0 + k p ×a p (2)

[0056] Among them, a i is the linear acceleration a loaded in the direction of the input axis of the accelerometer i = a·cosθ, a ois the linear acceleration a applied in the direction of the output axis of the accelerometer 0 = a·sinθ, a p is the linear acceleration applied in the direction of the pendulum axis of the accelerometer, θ is the angle between the sensitive axis direction of the accelerometer and the input acceleration, k o and k p are respectively the cross-axis sensitivities of the accelerometer in the output axis and pendulum axis directions. Therefore, the technical object of the present invention is to measure k o and k p , that is, the cross-axis sensitivities of the accelerometer in the output axis and pendulum axis directions.

[0057] Before testing the cross-axis sensitivity of the accelerometer, the accelerometer to be tested needs to be installed. As Figure 2 shown, when the accelerometer to be tested is fixed to the tabletop of the slave centrifuge, the sensitive axis of the accelerometer to be tested is located on the line connecting the rotation centers of the main centrifuge and the slave centrifuge, and the sensitive centroid of the accelerometer to be tested is located at the center of the slave centrifuge.

[0058] As Figure 3 shown, a method for testing the cross-axis sensitivity of an accelerometer provided in this embodiment mainly includes the following steps:

[0059] S1. Power on the main centrifuge and the slave centrifuge, make the slave centrifuge return to zero and be positioned at the zero position, fix the accelerometer to be tested to the tabletop of the slave centrifuge, power on the accelerometer to be tested, and when the main centrifuge is stationary, position the slave centrifuge at the zero position, wait for the thermal stable output value of the accelerometer to be tested to be stable, and record the output U of the accelerometer to be tested at this time 0 .

[0060] Further, step S1 is specifically:

[0061] After the accelerometer to be tested is powered on, the main centrifuge does not rotate, and the slave centrifuge is positioned at the zero position (i.e., 0° angle). At this time, the output of the accelerometer to be tested is measured as U 0 , and each parameter in formula (2) is that the external acceleration is 0g, the angle between the sensitive axis direction of the accelerometer and the external acceleration is 0°, the input axis acceleration is a i = 0g, the output axis acceleration is 0g, the pendulum axis acceleration a p = 1g. Substituting into formula (2) gives:

[0062] U 0 = k 0 + k 1 ×0g + k 2 ×(0g) 2 + k o ×0g + k p ×1g

[0063] U 0 = k 0 + k p ×lg(3)

[0064] where k 0 is the zero bias of the accelerometer, and k p is the cross-axis sensitivity in the direction of the pendulum axis of the accelerometer, and a p is the acceleration of the pendulum axis.

[0065] S2. Set the output acceleration of the main centrifuge to the preset value a, start the main centrifuge, keep the angle of the slave centrifuge at zero degrees, and record the output U of the accelerometer under test at this time 1 .

[0066] Furthermore, step S2 is specifically as follows:

[0067] Set the output acceleration of the main centrifuge to the preset value a (such as 10g), start the main centrifuge. Since there is an acceleration input to the sensitive axis of the accelerometer, the output value of the accelerometer will change. At this time, the measured output of the accelerometer is U 1 , and the parameters in Equation (2) are that the external acceleration is a, the angle between the sensitive axis direction of the accelerometer and the external acceleration is 0°, the input axis acceleration is a i = a·cos0°, the output axis acceleration is a o = a·sin0°, the acceleration of the pendulum axis a p = 1g. Substituting into Equation (2) gives:

[0068] U 1 = k 0 + k 1 ×a·cos0° + k 2 ×(a·cos0°) 2 + k o ×a·sin0° + k p ×1g

[0069] U 1 = k 0 + k 1 ×a + k 2 ×a 2 + k p ×1g (4)

[0070] where k 0 is the zero bias of the accelerometer, k 1 is the scale factor of the accelerometer, k p is the cross-axis sensitivity in the direction of the pendulum axis of the accelerometer, and a p is the acceleration of the pendulum axis.

[0071] S3. While the main centrifuge is continuously rotating, set the slave centrifuge to the position mode and rotate it to a 90° angle, and record the output U of the accelerometer at this time 2 .

[0072] Further, step S3 is specifically as follows:

[0073] While keeping the main centrifuge rotating, set the slave centrifuge to the position mode, rotate the slave centrifuge to a 90° angle, and the output of the accelerometer measured at this time is U 2 , and each parameter in formula (2) is that the external acceleration is a, the included angle between the sensitive axis direction of the accelerometer and the external acceleration is 0°, the input axis acceleration is a i = a·cos90°, the output axis acceleration is a o = a·sin90°, the pendulum axis acceleration a p = 1g, substituting into formula (2) we can get:

[0074] U 2 = k 0 + k 1 × a·cos90° + k 2 × (a·cos90°) 2 + k o × a·sin90° + k p × 1g

[0075] U 2 = k 0 + k o × a + k p × 1g (5)

[0076] Among them, k 0 is the zero bias of the accelerometer, k o is the cross-axis sensitivity of the accelerometer in the output axis direction, k p is the cross-axis sensitivity of the accelerometer in the pendulum axis direction, a p is the pendulum axis acceleration.

[0077] S4. Continue to keep the main centrifuge rotating, set the slave centrifuge to the position mode and rotate it to a 180° angle, and record the output U of the accelerometer at this time 3 .

[0078] Further, step S4 is specifically as follows:

[0079] While keeping the main centrifuge rotating, set the slave centrifuge to the position mode, rotate the slave centrifuge to a 180° angle, and the output of the accelerometer measured at this time is U 3 , and each parameter in formula (2) is that the external acceleration is a, the included angle between the sensitive axis direction of the accelerometer and the external acceleration is 180°, the input axis acceleration is a i= a·cos180°, the output shaft acceleration is a o = a·sin180°, the pendulum shaft acceleration a p = 1g, substituting into Equation (2) gives:

[0080] U 3 = k 0 + k 1 × a·cos180° + k 2 ×(a·cos180°) 2 + k o × a·sin180° + k p × 1g

[0081] U 3 = k 0 - k 1 × a + k 2 × a 2 + k p × 1g (6)

[0082] where k 0 is the zero bias of the accelerometer, k 1 is the scale factor of the accelerometer, k p is the cross-axis sensitivity in the direction of the pendulum shaft of the accelerometer, a p is the pendulum shaft acceleration.

[0083] S5. Still keep the main centrifuge rotating, set the slave centrifuge to the position mode and rotate it to the 270° angle, and record the output U of the accelerometer at this time 4 .

[0084] Furthermore, step S5 is specifically:

[0085] While keeping the main centrifuge rotating, set the slave centrifuge to the position mode, rotate the slave centrifuge to the 270° angle, and the output of the accelerometer measured at this time is U 4 , and the parameters in Equation (2) are that the external acceleration is a, the included angle between the sensitive axis direction of the accelerometer and the external acceleration is 270°, and the input shaft acceleration is a i = a·cos270°, the output shaft acceleration is a o = a·sin270°, the pendulum shaft acceleration a p = 1g, substituting into Equation (2) gives:

[0086] U 4 = k 0 + k 1 × a·cos270° + k 2 ×(a·cos270°) 2 + k o × a·sin270° + kp ×1g

[0087] U 4 =k 0 -k o ×a + k p ×1g(7)

[0088] where k 0 is the zero bias of the accelerometer, k o is the cross-axis sensitivity of the accelerometer in the output axis direction, k p is the cross-axis sensitivity of the accelerometer in the pendulum axis direction, and a p is the pendulum axis acceleration.

[0089] S6. According to the cross-axis sensitivity calculation formula of the accelerometer k o =k 1 ×(U 2 -U 4 ) / (U 1 -U 3 ), calculate the cross-axis sensitivity k o of the accelerometer output axis.

[0090] Furthermore, in step S6, calculating the cross-axis sensitivity k o of the output axis is specifically:

[0091] Substitute Equation (3) into Equations (4)-(7) respectively, and we can get:

[0092] U 1 =U 0 +k 1 ×a + k 2 ×a 2

[0093] U 2 =U 0 +k o ×a

[0094] U 3 =U 0 -k 1 ×a + k 2 ×a 2

[0095] U 4 =U 0 -k o ×a

[0096] Furthermore, we can get:

[0097] (U 1 -U 3 ) / 2 = k 1 ×a

[0098] (U 2 -U 4 ) / 2 = k o ×a

[0099] By dividing the two equations above and combining them, the cross-axis sensitivity k of the accelerometer output axis can be obtained o :

[0100] k o = k 1 ×(U 2 -U 4 ) / (U 1 -U 3 ) (8)

[0101] S7. Reinstall the accelerometer under test so that the pendulum axis and input axis of the accelerometer under test are on the installation plane, and repeat steps S1 - S6. Accordingly, calculate the cross-axis sensitivity k of the accelerometer pendulum axis p , specifically as follows:

[0102] S71. Power on the main centrifuge and the slave centrifuge, zero the slave centrifuge, and position the slave centrifuge at the zero position

[0103] S72. Through the installation fixture, place the pendulum axis and input axis of the accelerometer under test on the installation plane

[0104] S73. Complete the electrical connections required for accelerometer testing

[0105] S74. Power on the accelerometer. The main centrifuge does not rotate, and the angle of the slave centrifuge is positioned at the zero position (i.e., 0° angle). When the thermal stability output value of the accelerometer is stable, the output of the accelerometer measured at this time is U 0 ;

[0106] S75. Set the output acceleration of the main centrifuge to a certain value a (such as approximately 10g), start the main centrifuge, and keep the angle of the slave centrifuge at the zero degree angle. At this time, the output of the accelerometer measured is U 1 ;

[0107] S76. Keep the main centrifuge rotating, set the slave centrifuge to the position mode, and rotate the slave centrifuge to the 90° angle. At this time, the output of the accelerometer measured is U 2 ;

[0108] S77. Keep the main centrifuge rotating, set the slave centrifuge to the position mode, and rotate the slave centrifuge to the 180° angle. At this time, the output of the accelerometer measured is U 3 ;

[0109] S78. Keep the main centrifuge rotating, set the slave centrifuge to the position mode, and rotate the slave centrifuge to the 270° angle. At this time, the output of the accelerometer measured is U4 ;

[0110] S79. According to the cross-axis sensitivity calculation formula of the accelerometer k p = k 1 ×(U 2 - U 4 ) / (U 1 - U 3 ), the cross-axis sensitivity k p of the output axis of the accelerometer is obtained.

[0111] This patent presents a concise and efficient method for measuring the cross-axis sensitivity of an accelerometer. Relying on the theoretical framework of the accelerometer output model, a novel cross-axis sensitivity calculation model is constructed. By rotating the dual centrifuge linear acceleration platform in multiple orientations, the present invention can apply dynamic acceleration to different axes of the accelerometer, thereby accurately calculating the value of the cross-axis sensitivity. The present invention significantly improves the test flexibility, can conveniently measure the cross-axis sensitivity under a wide range of acceleration conditions, and breaks through the limitation of traditional test means that are only limited to ±1g acceleration. By simplifying the operation process, this method not only greatly improves the experimental efficiency but also ensures the high-precision acquisition of the cross-axis sensitivity data between the output axis and the pendulum axis of the accelerometer in various acceleration environments, opening up a new test path for the engineering practice of the performance parameters of the accelerometer.

[0112] The technical features of the above embodiments can be combined arbitrarily. For the sake of concise description, not all possible combinations of the technical features in the above embodiments are described. However, as long as the combinations of these technical features do not conflict, they should all be considered as the scope recorded in this specification.

[0113] The above embodiments are the preferred embodiments of the present invention, but the embodiments of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications made without departing from the spirit and principle of the present invention shall be equivalent replacement methods and are all included in the protection scope of the present invention.

Claims

1. A method for testing the cross-axis sensitivity of an accelerometer, characterized in that: The following steps are involved: S1. Power on the master centrifuge and slave centrifuge, return the slave centrifuge to zero and position it at zero, fix the accelerometer to be tested on the table of the slave centrifuge, power on the accelerometer to be tested, and position the slave centrifuge at zero angle while the master centrifuge is stationary, wait for the thermal stability output value of the accelerometer to be tested to stabilize, and record the output value of the accelerometer to be tested at this time. U 0 When the accelerometer to be tested is fixed to the table of the slave centrifuge, the sensitive axis of the accelerometer to be tested is located on the line connecting the rotation centers of the master centrifuge and the slave centrifuge, and the sensitive center of mass of the accelerometer to be tested is located at the center of the slave centrifuge; S2. Set the output acceleration of the main centrifuge to the preset value a , start the main centrifuge, keep the angle of the slave centrifuge at zero degrees, and record the output of the accelerometer to be tested at this time U 1 ; S3. While the master centrifuge continues to rotate, set the slave centrifuge to position mode and rotate it to 90°, and record the output of the accelerometer at this time. U 2 ; S4. Keep the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 180°, and record the output of the accelerometer at this time. U 3 ; S5. Keep the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 270°, and record the output of the accelerometer at this time. U 4 ; S6. According to the accelerometer cross-axis sensitivity calculation formula k o = k 1 ×( U 2 - U 4 ) / ( U 1 - U 3 ), calculate the cross-axis sensitivity of the accelerometer output axis k o ,in k 1 is the scale factor of the accelerometer; S7, reinstall the accelerometer to be tested so that the pendulum axis and the input axis of the accelerometer to be tested are on the installation plane of the centrifuge, repeat steps S1-S6, and calculate the cross-axis sensitivity of the pendulum axis of the accelerometer accordingly k p .

2. A method for testing the cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: In step S1, the output of the accelerometer to be tested is U 0 The calculation formula is as follows: U 0 = k 0 + k p × a p ； in, k 0 is the zero bias of the accelerometer, k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

3. A method for testing the cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: In step S2, the output of the accelerometer is measured U 1 The calculation formula is as follows: U 1 = k 0 + k 1 × a+ k 2 × a 2 + k p × a p ； in, k 0 is the zero bias of the accelerometer, k 2 is the second-order coefficient of the accelerometer, k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

4. A method for testing cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: In step S3, the output of the accelerometer U 2 The calculation formula is as follows: U 2 = k 0 + k o × a + k p × a p ； in, k 0 is the zero bias of the accelerometer, a p is the pendulum axis acceleration.

5. A method for testing cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: In step S4, the output of the accelerometer U 3 The calculation formula is as follows: U 3 = k 0 - k 1 × a+ k 2 × a 2 + k p × a p ； in, k 0 is the zero bias of the accelerometer, k 2 is the second-order coefficient of the accelerometer, a p is the pendulum axis acceleration.

6. A method for testing cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: In step S5, the output of the accelerometer U 4 The calculation formula is as follows: U 4 = k 0 -k o × a + k p × a p ； in, k 0 is the zero bias of the accelerometer, a p is the pendulum axis acceleration.

7. A method for testing cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: The working table of the main centrifuge is parallel to the ground, the rotating axis of the main centrifuge is perpendicular to the ground, the slave centrifuge is installed on the turntable or rotating arm of the main centrifuge, and the table of the slave centrifuge is parallel to the ground, the rotating axis is parallel to the rotating axis of the main centrifuge, and there are two or more slave centrifuges, which are symmetrically installed on the circular table of the steady-speed table.

Images