A Batch Testing Method for Nonlinearity of High-Range MEMS Gyroscopes

Abstract

The present invention discloses a batch testing method for the nonlinearity of a large-range MEMS gyroscope, which measures the distance R of multiple large-range MEMS gyroscopes from the center of the tabletop. i Power is supplied to make the gyroscope work normally; the outputs of each gyroscope are collected and the mean value V is calculated. 0i Multiple angular velocity points ω are taken according to the full range. j According to the selected angular velocity points ω. j The turntable is controlled to rotate, the outputs of the gyroscopes are collected, and the mean value V is calculated. ij Calculate the output V of the gyroscope. out Use the collected V. ij 、V 0i and ω j Perform a third-order fitting on the output and angular velocity of the large-range MEMS gyroscope; calculate the scale factor g and sensitivity coefficient γ of the large-range MEMS gyroscope. gi : Respectively, the positive and negative sensitive axes of the gyroscope are directed towards the ground, data is collected, and the mean values V gi and V gi′ are calculated, and the zero bias g sensitivity coefficient λ of the gyroscope is calculated. gi : Calculate the nonlinearity of the gyroscope. The present invention improves the batch testing accuracy of the nonlinearity of the large-range MEMS gyroscope by resolving and compensating the g sensitivity of the gyroscope.

Description

Technical Field

[0001] The present invention belongs to the technical field of MEMS gyroscope testing, and particularly relates to a method for batch testing the non-linearity of a large-range MEMS gyroscope. Background Art

[0002] When testing the non-linearity of a large-range MEMS gyroscope, due to the large influence of the g (acceleration) sensitivity at high rotational speeds, a single gyroscope is installed at the center of the turntable tabletop for testing. Single-gyroscope testing has the disadvantages of high cost, uneconomicalness, and low efficiency. Summary of the Invention

[0003] The object of the present invention is to provide a method for batch testing the non-linearity of a large-range MEMS gyroscope, which improves the batch testing accuracy of the non-linearity of a large-range MEMS gyroscope by calculating and compensating the g sensitivity of the gyroscope.

[0004] The technical solution of the present invention is as follows:

[0005] A method for batch testing the non-linearity of a large-range MEMS gyroscope, comprising the steps of:

[0006] S1. Install multiple large-range MEMS gyroscopes on the turntable tabletop through a test fixture;

[0007] S2. Measure the distance R of each large-range MEMS gyroscope from the center of the tabletop i , where i is the serial number of each large-range MEMS gyroscope;

[0008] S3. Supply power to enable the large-range MEMS gyroscopes to operate normally;

[0009] S4. Collect the outputs of each MEMS gyroscope and calculate the mean value V 0i ;

[0010] S5. Take multiple angular velocity points ω according to the full range j ;

[0011] S6. Control the turntable to rotate according to the selected angular velocity points ω j and collect the outputs of the large-range MEMS gyroscopes and calculate the mean value V ij ;

[0012] S7. Calculate the output V of the gyroscope out ;

[0013] S8. Use the collected V ij , V 0i and ω j to perform a third-order fitting on the output of the large-range MEMS gyroscope and the angular velocity;

[0014] S9. Calculate the scale factor \(g\) and sensitivity coefficient \(\gamma\) of the large-range MEMS gyroscope according to the results of the third-order fitting. gi :

[0015] S10. Respectively place the positive and negative sensitive axes of the large-range MEMS gyroscope towards the ground and collect data to obtain the average values \(V\) gi and \(V\) gi′ , and calculate the zero bias \(g\) sensitivity coefficient \(\lambda\) of the large-range MEMS gyroscope gi :

[0016] S11. Perform \(g\) sensitivity compensation on the output of the large-range MEMS gyroscope;

[0017] S12. Use the compensated output \(V\) ij′ and angular velocity \(\omega\) j to perform linear fitting by the least squares method and calculate the non-linearity of the large-range MEMS gyroscope.

[0018] Preferably, in S7, calculate the gyroscope output \(V\) out , as shown in formula (1):

[0019] \(V\) out =k0 + \(\lambda\) g *a*k1 + k1*\(\omega\) + k1*\(\gamma\) g *a*\(\omega\) + k2*\(\omega\) 2 (1)

[0020] where: \(V\) out is the gyroscope output; k0 is the gyroscope zero bias; \(\lambda\) g is the gyroscope zero bias \(g\) sensitivity coefficient; a is the acceleration; k1 is the gyroscope first-order coefficient, i.e., the scale factor; \(\omega\) is the angular velocity; \(\gamma\) g is the gyroscope scale factor \(g\) sensitivity coefficient; k2 is the gyroscope second-order coefficient.

[0021] The acceleration a is the centrifugal force generated when the turntable rotates, and the acceleration is as shown in formula (2):

[0022] a = R*\(\omega\) 2 (2)

[0023] where: R is the distance from the gyroscope installation position to the center of the turntable tabletop;

[0024] Finally, the gyroscope output is obtained as shown in formula (3):

[0025] \(V\) out =k0 + \(\lambda\) g *R*\(\omega\) 2 *k1 + k1*\(\omega\) + k1*\(\gamma\) g *R*\(\omega\) 3 +k2*\(\omega\) 2 (3).

[0026] Preferably, in S8, the collected V ij , V 0i and ω j are used to perform a third-order fitting on the output of a large-range MEMS gyroscope and the angular velocity. The formula is as shown in formula (4):

[0027] V ij = α 0i + α 1i * ω j + α 2i * ω j 2 + α 3i * ω j 3 (4)

[0028] Wherein:

[0029] α0 i is the zero bias of the i-th large-range MEMS gyroscope; α1 i is the first-order coefficient of the i-th large-range MEMS gyroscope, i.e., the scale factor; α 2i is the second-order coefficient of the i-th large-range MEMS gyroscope after coupling the zero bias g sensitivity; α 3i is the third-order coefficient of the i-th large-range MEMS gyroscope after coupling the scale factor g sensitivity.

[0030] Preferably, in S9, the third-order coefficient obtained through formula (4) can be used to calculate the scale factor g sensitivity coefficient γ of the large-range MEMS gyroscope through formula (5) gi :

[0031]

[0032] Preferably, in S10, the positive and negative directions of the sensitive axis of the large-range MEMS gyroscope are respectively oriented towards the ground, and data is collected to obtain the average values V gi and V gi′ , and the zero bias g sensitivity coefficient λ of the large-range MEMS gyroscope is calculated through formula (6) gi :

[0033]

[0034] Preferably, in S11, g sensitivity compensation is performed on the output of the large-range MEMS gyroscope, as shown in formula (7):

[0035] V ij′ = V ij - λ gi * R i * ω j 2 * α1i -α 1i *γ gi *R i *ω j 3 (7).

[0036] Preferably, in S12, the compensated output V ij′ and the angular velocity ω j are used to perform linear fitting by the least squares method, and the nonlinearity of the large-range MEMS gyroscope is calculated through formula (8):

[0037]

[0038] Wherein:

[0039] K gn is the nonlinearity of the i-th large-range MEMS gyroscope;

[0040] V ij′ is the compensated output of the i-th large-range MEMS gyroscope at the j-th angular velocity point;

[0041] is the fitting value of the compensated output of the i-th large-range MEMS gyroscope at the j-th angular velocity point;

[0042] K g1 is the slope of the fitting straight line of the i-th large-range MEMS gyroscope;

[0043] X FS is the difference between the upper limit value and the lower limit value of the input angular velocity.

[0044] Preferably, in S5, for the angular velocity point ω j j is the selected serial number of the angular velocity point, including positive and negative angular velocity points, and the maximum value is the full-scale point, j ≥ 20.

[0045] The advantages of the present invention are:

[0046] The method for batch testing the nonlinearity of the large-range MEMS gyroscope proposed by the present invention improves the batch testing accuracy of the nonlinearity of the large-range MEMS gyroscope by resolving and compensating the g sensitivity of the gyroscope. Specific embodiments

[0047] The method for batch testing the nonlinearity of the large-range MEMS gyroscope proposed by the present invention includes the steps of:

[0048] S1. Install multiple large-range MEMS gyroscopes on the turntable tabletop through a test fixture;

[0049] S2. Measure the distance R of multiple large-range MEMS gyroscopes from the center of the tabletopi where \(i\) is the serial number of each large-range MEMS gyroscope;

[0050] S3. Power supply enables the large-range MEMS gyroscope to work properly.

[0051] S4. Collect the outputs of each MEMS gyroscope and calculate the mean value \(V\) 0i where \(i\) is the serial number of the large-range MEMS gyroscope.

[0052] S5. Take multiple angular velocity points \(\omega\) according to the full range j where \(\omega\) j and \(j\) is the serial number of the selected angular velocity point, including positive and negative angular velocity points, and the maximum value is the full-range point, \(j\geq20\).

[0053] S6. Control the turntable to rotate according to the selected angular velocity point \(\omega\) j collect the output of the large-range MEMS gyroscope and calculate the mean value \(V\) ij ; \(i\) is the serial number of the large-range MEMS gyroscope, and \(j\) is the serial number of the selected angular velocity point.

[0054] S7. Calculate the gyroscope output \(V\) out as shown in formula (1):

[0055] \(V\) out = \(k_0+\lambda\) g * \(a*k_1 + k_1*\omega + k_1*\gamma\) g * \(a*\omega + k_2*\omega\) 2 (1)

[0056] where: \(V\) out is the gyroscope output; \(k_0\) is the gyroscope zero bias; \(\lambda\) g is the gyroscope zero bias \(g\) sensitivity coefficient; \(a\) is the acceleration; \(k_1\) is the gyroscope first-order coefficient, i.e., the scale factor; \(\omega\) is the angular velocity; \(\gamma\) g is the gyroscope scale factor \(g\) sensitivity coefficient; \(k_2\) is the gyroscope second-order coefficient.

[0057] The acceleration \(a\) is the centrifugal force generated when the turntable rotates, and the acceleration is shown in formula (2):

[0058] \(a = R*\omega\) 2 (2)

[0059] where: \(R\) is the distance from the gyroscope installation position to the center of the turntable surface;

[0060] Finally, the gyroscope output is shown in formula (3):

[0061] \(V\) out = \(k_0+\lambda\) g * \(R*\omega\) 2 * \(k_1 + k_1*\omega + k_1*\gamma\)g *R*ω 3 +k2*ω 2 (3).

[0062] S8. Use the collected V ij , V 0i and ω j to perform a third-order fitting on the output and angular velocity of a large-range MEMS gyroscope. The formula is as shown in formula (4):

[0063] V ij = α 0i + α 1i *ω j + α 2i *ω j 2 + α 3i *ω j 3 (4)

[0064] Where:

[0065] α 0i is the zero bias of the i-th large-range MEMS gyroscope; α 1i is the first-order coefficient of the i-th large-range MEMS gyroscope, i.e., the scale factor; α 2i is the second-order coefficient of the i-th large-range MEMS gyroscope after coupling the zero bias g sensitivity; α 3i is the third-order coefficient of the i-th large-range MEMS gyroscope after coupling the scale factor g sensitivity.

[0066] S9. The third-order coefficient obtained through formula (4) can be used to calculate the scale factor g sensitivity coefficient γ of the large-range MEMS gyroscope through formula (5) gi :

[0067]

[0068] S10. Respectively place the positive and negative directions of the sensitive axis of the large-range MEMS gyroscope towards the ground and collect data to obtain the average values V gi and V gi′ , and calculate the zero bias g sensitivity coefficient λ of the large-range MEMS gyroscope through formula (6) gi :

[0069]

[0070] S11. Perform g sensitivity compensation on the output of the large-range MEMS gyroscope, as shown in formula (7):

[0071] V ij′ = V ij - λ gi *R i *ωj 2 *α 1i -α 1i *γ gi *R i *ω j 3 (7).

[0072] S12. Use the compensated output V ij′ and the angular velocity ω j to perform a linear fit by the least squares method and calculate the non-linearity of the large-range MEMS gyroscope through formula (8):

[0073]

[0074] Where:

[0075] K gn is the non-linearity of the i-th large-range MEMS gyroscope;

[0076] V ij′ is the output after compensation at the j-th angular velocity point of the i-th large-range MEMS gyroscope;

[0077] is the fitting value of the output after compensation at the j-th angular velocity point of the i-th large-range MEMS gyroscope;

[0078] K g1 is the slope of the fitting line of the i-th large-range MEMS gyroscope;

[0079] X FS is the difference between the upper limit value and the lower limit value of the input angular velocity.

[0080] The method for batch testing the non-linearity of the large-range MEMS gyroscope proposed by the present invention improves the batch testing accuracy of the non-linearity of the large-range MEMS gyroscope by resolving and compensating the g sensitivity of the gyroscope.

[0081] The above embodiments are only for illustrating the technical concept and features of the present invention, and their purpose is to enable those who are familiar with this technology to understand the content of the present invention and implement it accordingly, and cannot be used to limit the protection scope of the present invention. All modifications made according to the spirit of the main technical solution of the present invention should be covered within the protection scope of the present invention.

Claims

1. A batch testing method for the non-linearity of a large-range MEMS gyroscope, characterized in that, Including the steps: S1. Install multiple large-range MEMS gyroscopes on the turntable tabletop through a test fixture; S2. Measure the distance R of multiple high-range MEMS gyroscopes from the center of the tabletop i , where i is the serial number of each high-range MEMS gyroscope; S3. Supply power to enable the large-range MEMS gyroscopes to work properly; S4. Collect the outputs of each MEMS gyroscope and calculate the mean value V 0i ; S5. Take multiple angular velocity points ω over the full range j ; S6. Rotate the turntable according to the selected angular velocity point ω j and collect the output of the large-range MEMS gyroscope and calculate the mean value V ij ; S7. Calculate the gyroscope output V out ; S8. Use the collected V ij , V 0i and ω j to perform a third-order fitting on the output of a large-range MEMS gyroscope and the angular velocity; S9. Calculate the scale factor g and sensitivity coefficient γ of a large-range MEMS gyroscope based on the results of third-order fitting gi : S10. Orient the sensitive axes of the large-range MEMS gyroscope forward and backward towards the ground respectively, collect data, and calculate the mean values V gi and V gi′ , and calculate the zero bias g sensitivity coefficient λ of the large-range MEMS gyroscope gi : S11. Perform g-sensitivity compensation on the output of the large-range MEMS gyroscopes; S12. Use the compensated output V ij′ and the angular velocity ω j Perform linear fitting by the least squares method and calculate the nonlinearity of the large-range MEMS gyroscope.

2. The method for batch testing the nonlinearity of a large-range MEMS gyroscope according to claim 1, wherein In S7, calculate the gyroscope output V out , as shown in formula (1): V out = k0 + λ g *a*k1 + k1*ω + k1*γ g *a*ω + k2*ω 2 (1) Where: V out is the output of the gyroscope; k0 is the zero bias of the gyroscope; λ g is the zero bias g sensitivity coefficient of the gyroscope; a is the acceleration; k1 is the first-order coefficient of the gyroscope, i.e., the scale factor; ω is the angular velocity; γ g is the scale factor g sensitivity coefficient of the gyroscope; k2 is the second-order coefficient of the gyroscope; The acceleration a is the centrifugal force generated when the turntable rotates, and the acceleration is shown in formula (2): a = R * ω 2 (2) Where: R is the distance from the gyroscope installation position to the center of the turntable tabletop; Finally, the gyroscope output is obtained as shown in formula (3): V out = k0 + λ g *R*ω 2 *k1 + k1*ω + k1*γ g *R*ω 3 + k2*ω 2 (3).

3. The method for batch testing the nonlinearity of a large-range MEMS gyroscope according to claim 2, wherein In S8, the output of a large-range MEMS gyroscope and the angular velocity are fitted by using the collected V ij , V 0i and ω j to perform a third-order fitting, and the formula is as shown in formula (4): V ij = α 0i + α 1i * ω j + α 2i * ω j 2 + α 3i * ω j 3 (4) Where: α 0i is the zero bias of the i-th large-range MEMS gyroscope; α 1i is the first-order coefficient of the i-th large-range MEMS gyroscope, i.e., the scale factor; α 2i is the second-order coefficient after coupling the zero bias g sensitivity of the i-th large-range MEMS gyroscope; α 3i is the third-order coefficient after coupling the scale factor g sensitivity of the i-th large-range MEMS gyroscope.

4. The method for batch testing the non-linearity of a large-range MEMS gyroscope according to claim 3, characterized in that, In S9, the third-order coefficients obtained through Equation (4) can be used to calculate the scale factor g and sensitivity coefficient γ of a large-range MEMS gyroscope through Equation (5). gi :

5. The method for batch testing the non-linearity of a large-range MEMS gyroscope according to claim 4, wherein In S10, the positive and negative directions of the sensitive axis of the large-range MEMS gyroscope are respectively directed towards the ground, and data is collected to obtain the mean value V gi and V gi′ , and the zero bias g sensitivity coefficient λ of the large-range MEMS gyroscope is calculated through formula (6) gi :

6. The method for batch testing the nonlinearity of a large-range MEMS gyroscope according to claim 5, wherein In S11, perform g-sensitivity compensation on the output of the large-range MEMS gyroscopes, as shown in formula (7): V ij′ = V ij - λ gi * R i * ω j 2 * α 1i - α 1i * γ gi * R i * ω j 3 (7).

7. The method for batch testing the nonlinearity of a large-range MEMS gyroscope according to claim 6, wherein In S12, the compensated output V ij′ and the angular velocity ω j are used to perform linear fitting by the least squares method, and the nonlinearity of the large-range MEMS gyroscope is calculated through Equation (8): Where: K gn is the nonlinearity of the i-th large-range MEMS gyroscope; V ij′ is the output after compensation for the j-th angular velocity point of the i-th large-range MEMS gyroscope; is the fitted output value after compensation for the j-th angular velocity point of the i-th large-range MEMS gyroscope; K g1 is the slope of the fitted straight line for the ith large-range MEMS gyroscope; X FS is the difference between the upper limit value and the lower limit value of the input angular velocity.

8. The method for batch testing the nonlinearity of a large-range MEMS gyroscope according to claim 7, wherein In S5, the angular velocity point ω j where j is the selected serial number of the angular velocity point, including positive and negative angular velocity points, and the maximum value is the full scale point, j ≥ 20.

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