Test method for obtaining accelerometer cross axis sensitivity

Abstract

The invention discloses a method for testing the sensitivity of a cross axis of an accelerometer, which is realized through a double-centrifugal-machine system and comprises the following steps of: firstly, fixing the accelerometer to be tested on a slave centrifugal machine, enabling the slave centrifugal machine to return to zero and be positioned at a zero position, and recording the output U0 of the accelerometer to be tested; thirdly, the output acceleration of the main centrifugal machine is set to be a preset value a, the main centrifugal machine is started, the angle of the auxiliary centrifugal machine is kept at the zero-degree angle, and the output U1 of the accelerometer to be measured at the moment is recorded; then, respectively positioning to 90 degrees, 180 degrees and 270 degrees from the centrifugal machine, and recording outputs U2, U3 and U4 of the to-be-measured accelerometer at each position; calculating the sensitivity ko of the cross axis of the output shaft by using a formula ko = k1 * (U2-U4) / (U1-U3); and finally, re-installing the accelerometer, repeating the steps, and calculating the sensitivity kp of the cross axis of the pendulum shaft. The method can accurately measure the cross axis sensitivity of the accelerometer, improves the measurement efficiency and accuracy, and is suitable for various high-precision accelerometer test scenes.

Description

Technical Field

[0001] The invention belongs to the technical field of accelerometers, and in particular 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 equipment, industrial automation, aerospace and military navigation systems to measure the acceleration changes of objects. In the research and development, production and practical application 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 coefficient, among which cross-axis sensitivity is particularly critical because it directly affects the response of the accelerometer in the direction of the non-sensitive axis, thereby affecting the overall measurement accuracy. An ideal accelerometer should only respond to changes in acceleration in the direction of its sensitive axis, but in practice, due to factors such as manufacturing process, material properties and design structure, the accelerometer will also produce a certain output in the orthogonal direction, which is the so-called cross-axis error. The cross-axis sensitivity is a parameter used to quantify the degree of this error. The lower its value, the smaller the response of the accelerometer in the direction of the non-sensitive axis and the better the performance.

[0003] At present, 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 the accelerometer. This scheme achieves a high-precision calibration through a nonlinear model and a step-by-step parameter linearization method, but the process is cumbersome and costly, and the cross-axis sensitivity value can only be obtained within the acceleration range of ±1g. In addition, the traditional method is limited by the acceleration range that the dividing head can provide, and it is impossible to fully 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 under ±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 ±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 nonlinear 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 the accelerometer within the full range has become a technical problem that needs to be solved urgently. Summary of the invention

[0006] The main purpose of the present invention is to overcome the shortcomings and deficiencies of the prior art and to provide a test method for obtaining the cross-axis sensitivity of an accelerometer. The test method of the present invention can obtain the cross-axis sensitivity under different lateral acceleration inputs, thereby improving the accuracy of the accelerometer output model.

[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, comprising the following steps:

[0009] S1. Power on the master centrifuge and the 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 angle at zero when the master centrifuge is stationary, wait for the thermal stability output value of the accelerometer to be tested to stabilize, and record the output U0 of the accelerometer to be tested at this time;

[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, keep the angle of the slave centrifuge at zero degrees, and record the output U1 of the accelerometer to be tested at this time;

[0011] S3. While the master centrifuge continues to rotate, set the slave centrifuge to position mode and rotate it to 90°, and record the output U2 of the accelerometer at this time;

[0012] S4, keep the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 180°, and record the output U3 of the accelerometer at this time;

[0013] S5, still keeping the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 270°, and record the output U4 of the accelerometer at this time;

[0014] S6. Calculate the accelerometer cross-axis sensitivity according to the formula k o =k1×(U2-U4) / (U1-U3), the cross-axis sensitivity k of the accelerometer output axis is calculated o ;

[0015] 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 k of the pendulum axis of the accelerometer accordingly. p .

[0016] As a preferred technical solution, in step S1, 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.

[0017] As a preferred technical solution, in step S1, the output U0 of the accelerometer to be tested is calculated as follows:

[0018] U0=k0+k p ×a p

[0019] Where k0 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.

[0020] As a preferred technical solution, in step S2, the output U1 of the accelerometer is calculated as follows:

[0021] U1=k0+k1×a+k2×a 2 +k p ×a p

[0022] Among them, k0 is the zero bias of the accelerometer, a is the acceleration of the external input, k1 is the scale factor of the accelerometer, k2 is the second-order coefficient of the accelerometer, and k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

[0023] As a preferred technical solution, in step S3, the calculation formula of the output U2 of the accelerometer is as follows:

[0024] U2=k0+k o ×a+k p ×a p

[0025] Among them, k0 is the zero bias of the accelerometer, a is the acceleration input from the outside, and k o The cross-axis sensitivity of the accelerometer in the direction of the output axis, k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

[0026] As a preferred technical solution, in step S4, the calculation formula of the output U3 of the accelerometer is as follows:

[0027] U3=k0-k1×a+k2×a 2 +k p ×a p

[0028] Among them, k0 is the zero bias of the accelerometer, a is the acceleration of the external input, k1 is the scale factor of the accelerometer, k2 is the second-order coefficient of the accelerometer, and k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

[0029] As a preferred technical solution, in step S5, the calculation formula of the output U4 of the accelerometer is as follows:

[0030] U4=k0-k o ×a+k p ×a p

[0031] Among them, k0 is the zero bias of the accelerometer, a is the acceleration input from the outside, and k o The cross-axis sensitivity of the accelerometer in the direction of the output axis, k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

[0032] As a preferred technical solution, the working surface 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 working surface 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 surface of the steady-speed table.

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

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

[0035] 1. Enhanced test flexibility: By utilizing the different rotation positions of the dual centrifuge linear acceleration turntable, the present invention can obtain a series of cross-axis sensitivities under different acceleration levels, rather than just being limited to the traditional ±1g condition. This greatly broadens the test range and makes it possible to evaluate the performance of the accelerometer under various working conditions.

[0036] 2. Simplify the test process: Compared with traditional methods, the method of the present invention simplifies the test steps, reduces the complexity of the operation and the time required. This not only saves resources, but also reduces the test cost and improves the overall test efficiency.

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

[0038] 4. Promote 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 aerospace, automotive industry, consumer electronics and other fields, accelerate product development cycle, and improve the performance of the final product. BRIEF DESCRIPTION OF THE DRAWINGS

[0039] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings required for use in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without creative work.

[0040] Figure 1 This is a schematic diagram of the principle of the dual centrifuge linear acceleration turntable of the present invention;

[0041] Figure 2 This is a schematic diagram of the accelerometer test installation of the present invention;

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

[0043] Description of the accompanying figures: 1-main centrifuge; 2-slave centrifuge; 3-rotating axis of the main centrifuge. DETAILED DESCRIPTION

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

[0045] Reference to "embodiments" in this application means that a particular feature, structure, or characteristic described in conjunction with the embodiments may be included in at least one embodiment of the present application. The appearance of the phrase in various locations 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. It is explicitly and implicitly understood by those skilled in the art that the embodiments described in this application may be combined with other embodiments.

[0046] For example, certain words 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 differences in names as a way to distinguish components, but use differences in the functions of components as the criteria for distinction. For example, "including" mentioned throughout the specification and claims is an open term, so 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] The present invention provides a test method for obtaining the cross-axis sensitivity of an accelerometer, which is based on a dual centrifuge linear acceleration turntable. Figure 1 The figure shows the principle diagram of the dual centrifuge linear acceleration turntable. The dual centrifuge linear acceleration turntable consists of a main centrifuge 1 and a slave centrifuge 2. The acceleration signal generated by the centrifuge can be used as an input to calibrate the accelerometer being calibrated. The working table of the main centrifuge 1 is parallel to the ground, and the rotation axis 3 of the main centrifuge is perpendicular to the ground. The slave centrifuge is installed on the turntable or arm of the main centrifuge, and its table 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 of the steady-speed table.

[0048] When conducting the accelerometer cross-axis sensitivity test, the accelerometer to be tested is installed on the table of the slave centrifuge so that the sensitive axis of the calibrated accelerometer is on the line connecting the center of the main centrifuge and the center of the slave centrifuge; after the main centrifuge and the slave centrifuge are closed and fixed, the main centrifuge rotates at a constant speed at an angular rate ω1, generating a certain centrifugal acceleration a. The magnitude of acceleration a is determined by the angular rate ω1 of the main centrifuge and the working radius of the accelerometer, and the direction of acceleration a is from the rotation center of the main centrifuge to the direction of the center of mass of the sensitive structure of the accelerometer.

[0049] At present, the slave centrifuge has two working modes. The first mode is the rate mode. While the main centrifuge rotates, the slave centrifuge rotates at a constant speed at an angular rate of ω2. 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 at 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 acceleration acting on the calibrated accelerometer.

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

[0051] The accelerometer is sensitive to acceleration, that is, its output will change when there is external acceleration input. The most basic output expression of the accelerometer is:

[0052] U out =k0+ k1×ai (1)

[0053] Among them, U out is the output of the accelerometer; k0 is the zero bias of the accelerometer, that is, the output of the accelerometer without acceleration input; k1 is the scale factor of the accelerometer, that is, the scale 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 accelerometer input axis.

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

[0055] U out = k0+ k1×a i +k2×a i 2 + k o ×a0 + k p ×a p (2)

[0056] Among them, a i is the linear acceleration a loaded in the direction of the accelerometer input axis i =a·cosθ,a o is the linear acceleration a0=a·sinθ loaded in the direction of the accelerometer output axis, a p is the linear acceleration loaded on the accelerometer’s pendulum axis, θ is the angle between the accelerometer’s sensitive axis and the input acceleration, k o and k p are the cross-axis sensitivities of the accelerometer in the output axis and the swing axis directions, respectively. Therefore, the technical purpose of the present invention is to measure k o and k p , that is, the cross-axis sensitivity of the accelerometer in the direction of the output axis and the pendulum axis.

[0057] Before the accelerometer cross-axis sensitivity test, the accelerometer to be tested needs to be installed, such as Figure 2 As shown, 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.

[0058] like Figure 3 As shown, the present embodiment provides a method for testing the cross-axis sensitivity of an accelerometer, which mainly includes the following steps:

[0059] S1. Power on the master centrifuge and the 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 when the master centrifuge is stationary, wait for the thermal stability output value of the accelerometer to be tested to stabilize, and record the output U0 of the accelerometer to be tested at this time.

[0060] Furthermore, step S1 is specifically as follows:

[0061] After the accelerometer to be tested is powered on, the main centrifuge does not rotate and is positioned at zero position (i.e., 0° angle) from the centrifuge angle. At this time, the output of the accelerometer to be tested is measured as U0, and the parameters in formula (2) are: the external acceleration is 0g, the angle between the accelerometer sensitive axis and the external acceleration is 0°, and the input axis acceleration is a i =0g, the output shaft acceleration is 0g, the pendulum shaft acceleration is a p =1g, substituting into formula (2) we can get:

[0062] U0=k0+k1×0g+k2×(0g) 2 +k o ×0g+k p ×1g

[0063] U0=k0+k p ×1g (3)

[0064] Where k0 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.

[0065] S2. Set the output acceleration of the main centrifuge to a preset value a, start the main centrifuge, keep the angle of the slave centrifuge at zero degrees, and record the output U1 of the accelerometer to be tested at this time.

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

[0067] Set the output acceleration of the main centrifuge to a preset value a (such as 10g), start the main centrifuge, and because the accelerometer sensitive axis has acceleration input, the output value of the accelerometer will change. At this time, the output of the accelerometer is measured to be U1, and the parameters in formula (2) are: the external acceleration is a, the angle between the accelerometer sensitive axis and the external acceleration is 0°, and the input axis acceleration is a i =a·cos0°, the output shaft acceleration is a o =a·sin0°, pendulum axis acceleration a p =1g, substituting into formula (2) we can get:

[0068] U1=k0+k1×a·cos0°+k2×(a·cos0°)2 +k o ×a·sin0°+k p ×1g

[0069] U1=k0+k1×a+k2×a 2 +k p ×1g (4)

[0070] Where k0 is the zero bias of the accelerometer, k1 is the scale factor of the accelerometer, and k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

[0071] S3. While the master centrifuge continues to rotate, set the slave centrifuge to position mode and rotate it to 90°, and record the output U2 of the accelerometer at this time.

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

[0073] While keeping the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 90°. At this time, the output of the accelerometer is measured as U2, and the parameters in formula (2) are: the external acceleration is a, the angle between the accelerometer sensitive axis and the external acceleration is 0°, and the input axis acceleration is a i =a·cos90°, the output shaft acceleration is a o =a·sin90°, pendulum axis acceleration a p =1g, substituting into formula (2) we can get:

[0074] U2=k0+k1×a·cos90°+k2×(a·cos90°) 2 +k o ×a·sin90°+k p ×1g

[0075] U2=k0+k o ×a+k p ×1g (5)

[0076] Where k0 is the zero bias of the accelerometer, k o The cross-axis sensitivity of the accelerometer in the direction of the output axis, k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

[0077] S4. Keep the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 180°, and record the output U3 of the accelerometer at this time.

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

[0079] While keeping the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 180°. At this time, the output of the accelerometer is measured as U3, and the parameters in formula (2) are: the external acceleration is a, the angle between the accelerometer sensitive axis and the external acceleration is 180°, and the input axis acceleration is a i =a·cos180°, the output shaft acceleration is a o =a·sin180°, the acceleration of the pendulum axis is a p =1g, substituting into formula (2) we can get:

[0080] U3=k0+k1×a·cos180°+k2×(a·cos180°) 2 +k o ×a·sin180°+k p ×1g

[0081] U3=k0-k1×a+k2×a 2 +k p ×1g (6)

[0082] Where k0 is the zero bias of the accelerometer, k1 is the scale factor of the accelerometer, and k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

[0083] S5. Still keeping the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to an angle of 270°, and record the output U4 of the accelerometer at this time.

[0084] Furthermore, step S5 is specifically as follows:

[0085] While keeping the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 270°. At this time, the output of the accelerometer is measured as U4, and the parameters in formula (2) are: the external acceleration is a, the angle between the accelerometer sensitive axis and the external acceleration is 270°, and the input axis acceleration is a i =a·cos270°, the output shaft acceleration is a o =a·sin270°, the acceleration of the pendulum axis is a p =1g, substituting into formula (2) we can get:

[0086] U4=k0+k1×a·cos270°+k2×(a·cos270°) 2 +k o ×a·sin270°+k p ×1g

[0087] U4=k0-k o ×a+kp ×1g (7)

[0088] Where k0 is the zero bias of the accelerometer, k o The cross-axis sensitivity of the accelerometer in the direction of the output axis, k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

[0089] S6. Calculate the accelerometer cross-axis sensitivity according to the formula k o =k1×(U2-U4) / (U1-U3), the cross-axis sensitivity k of the accelerometer output axis is calculated o .

[0090] Further, in step S6, the cross-axis sensitivity k of the output axis is calculated o Specifically:

[0091] Substituting formula (3) into formula (4)-formula (7) respectively, we can get:

[0092] U1=U0+k1×a+k2×a 2

[0093] U2=U0+k o ×a

[0094] U3=U0-k1×a+k2×a 2

[0095] U4=U0-k o ×a

[0096] Then we can get:

[0097] (U1-U3) / 2=k1×a

[0098] (U2-U4) / 2=k o ×a

[0099] The cross-axis sensitivity k of the accelerometer output axis can be obtained by dividing the above two equations. o :

[0100] k o =k1×(U2-U4) / (U1-U3) (8)

[0101] 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, repeat steps S1-S6, and calculate the cross-axis sensitivity k of the pendulum axis of the accelerometer accordingly. p , as follows:

[0102] S71, powering on the master centrifuge and the slave centrifuge, returning the slave centrifuge to zero, and positioning the slave centrifuge at zero position;

[0103] S72, by installing the fixture, make the pendulum shaft and input shaft of the accelerometer to be tested on the installation plane;

[0104] S73, completing the electrical connections required for the accelerometer test;

[0105] S74 powers on the accelerometer, the main centrifuge does not rotate, and the centrifuge is positioned at zero position (i.e., 0° angle). When the thermally stable output value of the accelerometer is stable, the output of the accelerometer is measured to be U0;

[0106] S75, setting the output acceleration of the main centrifuge to a certain value a (e.g., about 10 g), starting the main centrifuge, and keeping the centrifuge angle at zero degrees. At this time, the output of the accelerometer is measured to be U1;

[0107] S76, keep the main centrifuge rotating, set the slave centrifuge to position mode, rotate the slave centrifuge to 90°, and the output of the accelerometer is measured to be U2;

[0108] S77, keep the main centrifuge rotating, set the slave centrifuge to position mode, rotate the slave centrifuge to 180°, and the output of the accelerometer is measured to be U3;

[0109] S78, keep the main centrifuge rotating, set the slave centrifuge to position mode, rotate the slave centrifuge to 270°, and the output of the accelerometer is measured to be U4;

[0110] S79, according to the accelerometer cross-axis sensitivity calculation formula k p = k1 × (U2-U4) / (U1-U3) to obtain the cross-axis sensitivity k of the accelerometer output axis p .

[0111] This patent presents a streamlined 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. With the help of the rotation of the dual centrifuge linear acceleration platform in multiple directions, the present invention can apply dynamic acceleration to different axial directions of the accelerometer, thereby accurately calculating the value of the cross-axis sensitivity. The present invention significantly improves the test flexibility and can conveniently measure the cross-axis sensitivity under a wide range of acceleration conditions, breaking through the shackles of traditional testing methods that are limited to ±1g acceleration. By simplifying the operating 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 accelerometer output axis and the pendulum axis under a variety of acceleration environments, opening up a new test path for the engineering practice of accelerometer performance parameters.

[0112] The technical features of the above embodiments may be combined arbitrarily. To make the description concise, not all possible combinations of the technical features in the above embodiments are described. However, as long as there is no contradiction in the combination of these technical features, they should be considered to be within the scope of this specification.

[0113] The above embodiments are preferred implementation modes of the present invention, but the implementation modes of the present invention are not limited to the above embodiments. Any other changes, modifications, substitutions, combinations, and simplifications that do not deviate from the spirit and principles of the present invention should be equivalent replacement methods and are 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 the 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 angle at zero when the master centrifuge is stationary, wait for the thermal stability output value of the accelerometer to be tested to stabilize, and record the output U0 of the accelerometer to be tested at this time; S2, set the output acceleration of the main centrifuge to a preset value a, start the main centrifuge, keep the angle of the slave centrifuge at zero degrees, and record the output U1 of the accelerometer to be tested at this time; S3. While the master centrifuge continues to rotate, set the slave centrifuge to position mode and rotate it to 90°, and record the output U2 of the accelerometer at this time; S4, keep the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 180°, and record the output U3 of the accelerometer at this time; S5, still keeping the main centrifuge rotating, set the slave centrifuge to position mode and rotate it to 270°, and record the output U4 of the accelerometer at this time; S6. Calculate the accelerometer cross-axis sensitivity according to the formula k o =k1×(U2-U4) / (U1-U3), the cross-axis sensitivity k of the accelerometer output axis is calculated o ; 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 k of the pendulum axis of the accelerometer accordingly. p .

2. A method for testing the cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: In step S1, 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.

3. A method for testing the cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: In step S1, the output U0 of the accelerometer to be tested is calculated as follows: U0=k0+k p ×a p Where k0 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.

4. A method for testing cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: In step S2, the output U1 of the accelerometer is calculated as follows: U1=k0+k1×a+k2×a 2 +k p ×a p Among them, k0 is the zero bias of the accelerometer, a is the acceleration input to the sensitive axis of the accelerometer, k1 is the scale factor of the accelerometer, k2 is the second-order coefficient of the accelerometer, and k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

5. A method for testing the cross-axis sensitivity of an accelerometer according to claim 1, characterized in that: In step S3, the accelerometer output U2 is calculated as follows: U2=k0+k o ×a+k p ×a p Where k0 is the zero bias of the accelerometer, k o The cross-axis sensitivity of the accelerometer in the direction of the output axis, k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, 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 S4, the accelerometer output U3 is calculated as follows: U3=k0-k1×a+k2×a 2 +k p ×a p Among them, k0 is the zero bias of the accelerometer, a is the acceleration of the external input, k1 is the scale factor of the accelerometer, k2 is the second-order coefficient of the accelerometer, and k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, 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: In step S5, the accelerometer output U4 is calculated using the following formula: U4=k0-k o ×a+k p ×a p Among them, k0 is the zero bias of the accelerometer, a is the acceleration input from the outside, and k o The cross-axis sensitivity of the accelerometer in the direction of the output axis, k p is the cross-axis sensitivity of the accelerometer in the direction of the pendulum axis, a p is the pendulum axis acceleration.

8. 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.

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