Anti-vibration signal fusion method and system of MEMS accelerometer

Abstract

The invention provides an anti-vibration signal fusion method and system of an MEMS accelerometer. The method comprises the following steps: acquiring an interfered acceleration signal of the MEMS; a first mechanical sensing unit and a second mechanical sensing unit in the mechanical module are used for conducting signal conversion processing on the disturbed acceleration signal, and a first output capacitance signal and a second output capacitance signal are correspondingly obtained; the first mechanical sensing unit is a sensing unit with high VRE and low noise, and the second mechanical sensing unit is a sensing unit with low VRE and high noise; respectively performing voltage signal conversion processing on the first output capacitance signal and the second output capacitance signal to correspondingly obtain a first voltage output signal and a second voltage output signal; and performing calibration compensation processing on a nonlinear signal in the first voltage output signal by using the second voltage output signal to obtain a final acceleration output signal. Therefore, on the premise that the cost and the system size are not increased, the measurement precision is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of MEMS accelerometers, and in particular to an anti-vibration signal fusion method and system for a MEMS accelerometer. Background Art

[0002] With the rapid development of modern science and technology and industry, inertial measurement technology plays an increasingly critical role in many fields. As an important inertial measurement device, high-performance MEMS accelerometers have been widely used in various inertial measurement applications such as industrial inclinometers, unmanned aerial vehicle (UAV) flight control, and navigation systems due to their unique advantages such as small size, low power consumption, and easy integration. These application scenarios have extremely high requirements for measurement accuracy and stability, because any tiny measurement error may lead to serious consequences, such as affecting the normal operation of industrial equipment, reducing the flight safety of UAVs, and causing inaccurate positioning of navigation systems. However, in actual applications, high-performance MEMS (Micro-Electro-Mechanical Systems) accelerometers face many interference factors, among which vibration interference is a problem that cannot be ignored. It will have a significant impact on the measurement accuracy of the accelerometer, thereby triggering a series of technical challenges.

[0003] To address the impact of vibration interference on the measurement accuracy of high-performance MEMS accelerometers, the closest existing technologies currently focus on optimizing the accelerometer's structure and improving signal processing algorithms. In terms of structural optimization, researchers have designed special mechanical structures, such as using shock-absorbing materials and optimizing the accelerometer's packaging, to reduce the transfer of vibration energy, thereby reducing the impact of vibration on sensitive components within the accelerometer. In terms of signal processing algorithms, researchers are committed to developing algorithms that can identify and filter out vibration interference signals. For example, based on filter technology, by designing appropriate filter parameters, the accelerometer's output signal is processed to remove the vibration interference component and improve the quality of the measurement signal.

[0004] However, these existing technologies still have some urgent problems to be solved. In terms of structural optimization, although the use of shock-absorbing materials and optimized packaging can reduce the transmission of vibration energy to a certain extent, this method is often difficult to completely eliminate vibration interference, especially when facing complex and changing vibration environments, its effectiveness will be greatly reduced. Moreover, the special mechanical structure design may increase the size and cost of the accelerometer, which is contrary to the advantages of high-performance MEMS accelerometers such as small size and easy integration. In terms of signal processing algorithms, although filter-based technologies can filter out some vibration interference signals, they have difficulty in effectively processing special non-ideal responses such as VRE (Vibration Rectification Error). VRE is essentially a nonlinear response of the accelerometer to AC vibration interference, which will cause an abnormal offset in the DC component of the accelerometer output signal. Existing signal processing algorithms find it difficult to accurately identify and compensate for this offset, resulting in large errors in the measurement results and unable to meet the requirements of high-precision inertial measurement applications. Summary of the Invention

[0005] In order to solve the above problems existing in the prior art, the present invention provides a method and system for fusion of anti-vibration signals of a MEMS accelerometer.

[0006] The technical problem to be solved by the present invention is achieved through the following technical solutions:

[0007] In a first aspect, the present invention provides a method for fusion of anti-vibration signals of a MEMS accelerometer, comprising:

[0008] Obtaining a disturbed acceleration signal of the MEMS; the disturbed acceleration signal is an acceleration signal disturbed by vibration;

[0009] The first mechanical sensing unit and the second mechanical sensing unit in the mechanical module are used to perform signal conversion processing on the interfered acceleration signal, respectively, to obtain a first output capacitance signal and a second output capacitance signal; the first mechanical sensing unit is a sensing unit with high VRE and low noise, and the second mechanical sensing unit is a sensing unit with low VRE and high noise;

[0010] Performing voltage signal conversion processing on the first output capacitor signal and the second output capacitor signal respectively to obtain a first voltage output signal and a second voltage output signal respectively;

[0011] The second voltage output signal is used to perform calibration and compensation processing on the nonlinear signal in the first voltage output signal to obtain a final acceleration output signal; the final acceleration output signal is an acceleration signal with low noise and low VRE.

[0012] Optionally, the first mechanical sensing unit is a differential variable spacing capacitance sensor of a discrete mass block; and the second mechanical sensing unit is a differential variable area capacitance sensor of a discrete mass block.

[0013] Optionally, performing voltage signal conversion processing on the first output capacitor signal and the second output capacitor signal respectively to obtain a first voltage output signal and a second voltage output signal accordingly includes:

[0014] The first output capacitor signal and the second output capacitor signal are converted into voltage signals respectively by using a CV conversion circuit to obtain a first voltage output signal and a second voltage output signal.

[0015] Optionally, the first output capacitance signal is expressed as:

[0016]

[0017] Among them, C OUT1 represents the capacitance value of the first output capacitance signal, C0 represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable spacing capacitance sensor of the discrete mass block, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the oppositely arranged fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, a in Indicates the disturbed acceleration signal;

[0018] The second output capacitor signal is expressed as:

[0019]

[0020] Among them, C OUT2 represents the capacitance value of the second output capacitance signal, C0′ represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable area capacitance sensor of the discrete mass block, k′ represents the linear coefficient of the differential variable area capacitance sensor of the discrete mass block, and l0 represents the initial facing length between the movable plate and the corresponding fixed plate in the differential variable area capacitance sensor of the discrete mass block.

[0021] Optionally, using the second voltage output signal to perform calibration and compensation processing on a nonlinear signal in the first voltage output signal to obtain a final acceleration output signal includes:

[0022] Performing a cubic operation on the second voltage output signal to obtain a corresponding second voltage operation signal;

[0023] Calculating a nonlinear compensation coefficient based on the first voltage output signal and the second voltage operation signal;

[0024] The first voltage output signal is calibrated and compensated using the nonlinear compensation coefficient and the second voltage operation signal to obtain a final acceleration output signal.

[0025] Optionally, the nonlinear compensation coefficient is expressed as:

[0026]

[0027] Wherein, s represents the nonlinear compensation coefficient, C0 represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable spacing capacitance sensor of the discrete mass block, m represents the linear coefficient of the CV conversion circuit, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the relatively set fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, C0′ represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable area capacitance sensor of the discrete mass block, k′ represents the linear coefficient of the differential variable area capacitance sensor of the discrete mass block, and l0 represents the initial facing length of the movable plate and the corresponding fixed plate in the differential variable area capacitance sensor of the discrete mass block.

[0028] Optionally, performing calibration and compensation processing on the first voltage output signal using the nonlinear compensation coefficient and the second voltage operation signal to obtain a final acceleration output signal includes:

[0029] Multiplying the nonlinear compensation coefficient and the second voltage operation signal to obtain a calibration compensation value;

[0030] Subtracting the first voltage output signal from the calibration compensation value to obtain a final acceleration output signal;

[0031] The final acceleration output signal is expressed as:

[0032]

[0033] Among them, V OUT represents the final acceleration output signal, V1 represents the first voltage output signal, v3 represents the second voltage operation signal, S represents the nonlinear compensation coefficient, m represents the linear coefficient of the CV conversion circuit, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, C0 represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the relatively set fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, a in Indicates the disturbed acceleration signal.

[0034] In a second aspect, the present invention provides an anti-vibration signal fusion system for a MEMS accelerometer, comprising: an acquisition module, a mechanical module, a signal conversion module, and a compensation processing module; the compensation processing module comprises: a first operation circuit and a second operation circuit;

[0035] The acquisition module is used to: acquire the disturbed acceleration signal of the MEMS; the disturbed acceleration signal is an acceleration signal disturbed by vibration;

[0036] The mechanical module is configured to: utilize a first mechanical sensing unit and a second mechanical sensing unit in the mechanical module to perform signal conversion processing on the interfered acceleration signal, respectively, to obtain a first output capacitance signal and a second output capacitance signal accordingly; the first mechanical sensing unit is a sensing unit with high VRE and low noise, and the second mechanical sensing unit is a sensing unit with low VRE and high noise;

[0037] The signal conversion module is used to: perform voltage signal conversion processing on the first output capacitor signal and the second output capacitor signal respectively, and obtain a first voltage output signal and a second voltage output signal accordingly;

[0038] The first operation circuit and the second operation circuit are used to: use the second voltage output signal to calibrate and compensate the nonlinear signal in the first voltage output signal to obtain a final acceleration output signal; the final acceleration output signal is an acceleration signal with low noise and low VRE.

[0039] Optionally, the first mechanical sensing unit is a differential variable spacing capacitance sensor of a discrete mass block; the second mechanical sensing unit is a differential variable area capacitance sensor of a discrete mass block; the differential variable spacing capacitance sensor of the discrete mass block and the differential variable area capacitance sensor of the discrete mass block are both upper and lower symmetrical structures;

[0040] The differential variable spacing capacitance sensor of the discrete mass block and the differential variable area capacitance sensor of the discrete mass block are arranged on the same substrate in the mechanical module in the same direction.

[0041] The present invention provides a method and system for fusion of anti-vibration signals of a MEMS accelerometer. The method comprises: obtaining a disturbed acceleration signal of a MEMS; the disturbed acceleration signal is an acceleration signal disturbed by vibration; using a first mechanical sensing unit and a second mechanical sensing unit in a mechanical module to perform signal conversion processing on the disturbed acceleration signal, respectively, to obtain a first output capacitance signal and a second output capacitance signal; the first mechanical sensing unit is a sensing unit with high VRE and low noise, and the second mechanical sensing unit is a sensing unit with low VRE and high noise; performing voltage signal conversion processing on the first output capacitance signal and the second output capacitance signal, respectively, to obtain a first voltage output signal and a second voltage output signal; using the second voltage output signal to perform calibration and compensation processing on the nonlinear signal in the first voltage output signal, to obtain a final acceleration output signal; the final acceleration output signal is an acceleration signal with low noise and low VRE. Since it is difficult for a single type of accelerometer to have the advantages of both "low VRE" and "low noise", the present invention uses a low VRE and high noise sensor unit output signal to compensate for a high VRE and low noise sensor unit output signal, ultimately obtaining a low VRE and low noise acceleration signal, thereby combining the advantages of the two acceleration sensor units and greatly improving the anti-vibration signal fusion system's measurement accuracy for acceleration signals in complex and changeable vibration environments. Secondly, since the anti-vibration signal fusion system used in the method of the present invention has a simple structure and avoids special mechanical structure design, it avoids an increase in cost and volume. In summary, the method of the present invention improves the measurement accuracy of acceleration signals while maintaining no increase in cost and volume.

[0042] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] Figure 1 A schematic flow chart of a method for fusion of anti-vibration signals of a MEMS accelerometer provided in an embodiment of the present invention;

[0044] Figure 2 The schematic diagram of the structure of the mechanical module composed of the differential variable spacing capacitance sensor based on the discrete mass block and the differential variable area capacitance sensor based on the discrete mass block is exemplarily shown;

[0045] Figure 3 The schematic diagram of the structure of the mechanical module composed of the differential variable spacing sensing unit based on the shared mass block and the differential variable area sensing unit based on the shared mass block is exemplarily shown;

[0046] Figure 4The following is a schematic diagram showing the structure of a mechanical module composed of a high-range variable-distance sensing unit based on a shared mass block and a low-range variable-distance sensing unit based on a shared mass block;

[0047] Figure 5 The schematic diagram of the structure of a mechanical module composed of a far-end sensing unit and a near-end sensing unit based on a seesaw structure is exemplarily shown;

[0048] Figure 6 A schematic structural diagram of an anti-vibration signal fusion system for a MEMS accelerometer provided in an embodiment of the present invention. DETAILED DESCRIPTION

[0049] The present invention will be further described in detail below with reference to specific examples, but the embodiments of the present invention are not limited thereto.

[0050] In order to improve the measurement accuracy of acceleration signals in complex and changeable vibration environments, an embodiment of the present invention provides an anti-vibration signal fusion method for a MEMS accelerometer. Figure 1 A flow chart of a method for fusion of anti-vibration signals of a MEMS accelerometer provided by an embodiment of the present invention is shown as follows: Figure 1 Shown, including:

[0051] S101 : Acquire a disturbed acceleration signal of a MEMS.

[0052] In this embodiment, the disturbed acceleration signal is an acceleration signal disturbed by vibration.

[0053] S102 : Utilize the first mechanical sensing unit and the second mechanical sensing unit in the mechanical module to perform signal conversion processing on the interfered acceleration signal respectively, and obtain a first output capacitance signal and a second output capacitance signal accordingly.

[0054] The first mechanical sensing unit is a sensing unit with high VRE and low noise, and the second mechanical sensing unit is a sensing unit with low VRE and high noise.

[0055] Optionally, the first mechanical sensing unit is a differential variable spacing capacitance sensor of a discrete mass block; and the second mechanical sensing unit is a differential variable area capacitance sensor of a discrete mass block.

[0056] In some possible implementations, the mechanical module may further employ a differential variable spacing sensing unit of a shared mass block and a differential variable area sensing unit of a shared mass block as the first mechanical sensing unit and the second mechanical sensing unit, respectively.

[0057] In some possible implementations, the mechanical module may further employ a high-range variable-distance sensing unit of a shared mass block and a low-range variable-distance sensing unit of a shared mass block as the first mechanical sensing unit and the second mechanical sensing unit, respectively.

[0058] In some possible implementations, the mechanical module may further adopt a seesaw structure of a distal sensing unit and a proximal sensing unit, which serve as the first mechanical sensing unit and the second mechanical sensing unit respectively.

[0059] Correspondingly, Figure 2 The schematic diagram of the structure of the mechanical module composed of the differential variable spacing capacitance sensor based on the discrete mass block and the differential variable area capacitance sensor based on the discrete mass block is shown as an example. Figure 2 As shown, the differential variable spacing capacitance sensor 302 of the discrete mass block and the differential variable area capacitance sensor 303 of the discrete mass block are arranged on the same substrate of the mechanical module 200. The differential variable spacing capacitance sensor 302 of the discrete mass block includes a first detection mass block 304, a first fixed electrode plate 305, a first movable electrode plate 306, a second fixed electrode plate 307, and a first spring 308. Among them, the first movable electrode plate 306 can move relative to the second fixed electrode plate 307 with the first detection mass block 304, and the first detection mass block 304 is suspended by the first spring 308. The first movable electrode plate 306 and the first fixed electrode plate 305 constitute a first sensing capacitor C S1 The first movable plate 306 and the second fixed plate 307 form a second sensing capacitor C S2 . In the case of disturbed acceleration signal a in = 0, the distances between the first movable plate 306 and the first fixed plate 305 and the second fixed plate 307 are all C0; when the disturbed acceleration signal a along the X axis in When the first detection mass block 304 is displaced, the first movable plate 306 is displaced, thereby causing the first sensing capacitor C S1 and the second sensing capacitor C S2 The capacitance value changes, completing the conversion of acceleration signal to capacitance signal. The first sensing capacitor C S1 and the second sensing capacitor C S2 The expression is expressed as:

[0060]

[0061] Wherein, C0 represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable spacing capacitance sensor of the discrete mass block, and Δd represents the interference acceleration signal a in The displacement value of the first movable plate 306 under excitation, Δd, and the disturbed acceleration signal a inIn a linear relationship, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, and λ represents the modulation depth of the differential variable spacing capacitance sensor of the discrete mass block. According to formula (1), the first output capacitance signal C output by the differential variable spacing capacitance sensing unit is: OUT1 Expressed as:

[0062]

[0063] Since the modulation depth λ of the differential variable spacing capacitance sensor of the discrete mass block is usually much less than 1, when λ is very small, the geometric series expansion of formula (2) can be obtained:

[0064] C OUT1 =C02λ(1+λ 2 +λ 4 +…)=2C0(λ+λ 3 +λ 5 +…); (3)

[0065] Will Substituting into formula (3) and ignoring the higher order terms above the cubic term, we can get C OUT1 with a in The relationship is:

[0066]

[0067] Since VRE is caused by the nonlinearity of the sensing unit, eliminating C OUT1 Middle a in 3 The VRE compensation can be realized by adding the following items:

[0068] The differential variable area capacitance sensor 303 of the discrete mass block includes a second detection mass block 309, a third fixed plate 310, a fourth fixed plate 311, a second movable plate 312, a third movable plate 313, and a second spring 314. The second movable plate 312 and the third movable plate 313 can move relative to the fourth fixed plate 311 along with the second detection mass block 309, and the second detection mass block 309 is suspended by the second spring 314. The third movable plate 313 and the fourth fixed plate 311 form a first sensing capacitor C S1 ', the second movable plate 312 and the third fixed plate 310 form a second sensing capacitor C S2 ′. When the acceleration signal a is disturbed in = 0, the initial facing length between the movable plate and the corresponding fixed plate in the differential variable area capacitance sensor of the discrete mass block is expressed as l0; when the disturbed acceleration signal a along the X axis inWhen the second detection mass block 309 is displaced, the second movable plate 312 and the third movable plate 313 are displaced, thereby causing the first sensing capacitor C S1 ' and the second sensing capacitor C S2 ′ changes, completing the conversion of acceleration signal to capacitance signal. The first sensing capacitor C S1 ′ and the second sensing capacitor C S2 The expression of ′ is:

[0069]

[0070] Where C0′ represents the first sensing capacitance C in the differential variable area capacitance sensor of the discrete mass block. S1 ' or the second sensing capacitor C S2 ′, Δl represents the acceleration signal a in The displacement value of the third movable plate 313 under excitation, Δl, and the disturbed acceleration signal a in In a linear relationship, k' represents the linear coefficient of the differential variable area capacitance sensor of the discrete mass block, λ' represents the modulation depth of the differential variable area capacitance sensor of the discrete mass block, and l0 represents the initial facing length of the movable plate and the corresponding fixed plate in the differential variable area capacitance sensor of the discrete mass block. According to formula (5), the output capacitance C of the differential variable area capacitance sensing unit is: OUT2 It can be expressed as:

[0071]

[0072] From formula (4) and formula (6), we can get the first output capacitor signal C OUT1 Compared to the second output capacitance signal C OUT2 It has higher linearity, that is, lower VRE. However, under the same mechanical area limit, the differential variable area capacitance sensor of the discrete mass block requires additional mechanical area to provide a damping structure, while the differential variable spacing capacitance sensor of the discrete mass block does not require additional mechanical area. This additional mechanical area allocation causes the noise of the differential variable area capacitance sensor of the discrete mass block to be higher than that of the differential variable spacing capacitance sensor of the discrete mass block. Finally, after the processing of the above step S102, the mechanical module outputs the first output capacitance signal C with high VRE and low noise respectively. OUT1 The second output capacitor signal C with low VRE and high noise OUT2 That is, the differential variable pitch capacitance sensor 302 of the discrete mass block and the differential variable area capacitance sensor 303 of the discrete mass block serve as the first mechanical sensing unit 2002 and the second mechanical sensing unit 2003 respectively.

[0073] In some possible implementations, when a differential variable spacing sensing unit of a shared mass block and a differential variable area sensing unit of a shared mass block are used as the first mechanical sensing unit and the second mechanical sensing unit, respectively, the following calculation method can be used to represent the capacitance output signal of the first mechanical sensing unit and the capacitance output signal of the second mechanical sensing unit:

[0074] Figure 3 The schematic diagram of the structure of the mechanical module composed of the differential variable spacing sensing unit based on the shared mass block and the differential variable area sensing unit based on the shared mass block is shown as an example. Figure 3 As shown, the mechanical module 200 includes a third proof mass 402, a fifth fixed plate 403, a fourth movable plate 404, a sixth fixed plate 405, a seventh fixed plate 406, an eighth fixed plate 407, a fifth movable plate 408, a sixth movable plate 409, and a third spring 410. The fourth movable plate 404, the fifth movable plate 408, and the sixth movable plate 409 can move relative to the fifth fixed plate 403, the sixth fixed plate 405, the seventh fixed plate 406, and the eighth fixed plate 407 along with the third proof mass 402, and the third proof mass 402 is suspended by the third spring 410.

[0075] The fifth fixed electrode 403, the fourth movable electrode 404 and the sixth fixed electrode 405 constitute a differential variable distance sensing unit 411 of a shared mass block. The fourth movable electrode 404 and the fifth fixed electrode 403 constitute the first sensing capacitor C in the differential variable distance sensing unit of the shared mass block. SA1 The fourth movable electrode 404 and the sixth fixed electrode 405 constitute the second sensing capacitor C in the differential variable spacing sensing unit of the shared mass block. SA2 . The disturbed acceleration signal a in = 0, the distances between the fourth movable electrode 404 and the fifth fixed electrode 403 and the sixth fixed electrode 405 are all d A ; When the disturbed acceleration signal a along the X axis in When the third detection mass block 402 is displaced, the fourth movable plate 404 is displaced, thereby causing the first sensing capacitor C SA1 and the second sensing capacitor C SA2 The capacitance value changes. The acceleration signal-capacitance signal conversion is completed. According to formula (4), the output capacitance C of the differential variable spacing sensing unit 411 of the shared mass block is OUT3 It can be expressed as:

[0076]

[0077] Among them, C Ak represents the capacitance of the first sensing capacitor or the second sensing capacitor in the differential variable spacing sensing unit of the shared mass block, A is the linear coefficient corresponding to the differential variable spacing sensing unit of the shared mass block, and the interference acceleration signal a in The relationship between the displacement ΔA of the movable plate in the differential variable spacing sensing unit of the shared mass block is: ΔA = k A ·a in .

[0078] The seventh fixed electrode 406, the eighth fixed electrode 407, the sixth movable electrode 409, and the sixth movable electrode 409 constitute a differential variable area sensing unit 412 of a shared mass block. The sixth movable electrode 409 and the eighth fixed electrode 407 constitute a first sensing capacitor C of the differential variable area sensing unit of the shared mass block. SA1 ', the fifth movable electrode 408 and the seventh fixed electrode 406 form a second sensing capacitor C SA2 ′. Disturbed acceleration signal a in = 0, the initial facing lengths of the fifth movable electrode plate 408, the sixth movable electrode plate 409 and the corresponding fixed electrode plate are both l A ; When there is a disturbed acceleration signal a along the X axis in When the third detection mass block 402 is displaced, the fifth movable plate 408 and the sixth movable plate 409 are displaced, so that C SA1 ′ and C SA2 The capacitance of ′ changes. The conversion of acceleration signal to capacitance signal is completed. According to formula (6), the output capacitance C of the differential variable area sensing unit 412 of the shared mass block is OUT4 It can be expressed as:

[0079]

[0080] Among them, C A ′ represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable area sensing unit of the shared mass block, k A ′ is the linear coefficient of the differential variable area sensing unit of the shared mass block. According to the mechanical structure characteristics of the shared mass block, k A ′=k A ; Disturbed acceleration signal a in The relationship between the displacement ΔA′ of the movable plate in the differential variable area sensing unit of the shared mass block is: ΔA′=k A ′·a in .

[0081] From formula (7) and formula (8), we can get OUT3 In comparison, C OUT4It has higher linearity, that is, lower VRE; in the architecture of the shared detection mass block, in order to effectively suppress the deterioration of Brownian noise, the differential variable area comb structure (sensing unit) of the shared mass block only occupies a small part of the mechanical area, resulting in the number of its sensing units being far less than the differential variable spacing sensing unit, thereby making the overall acceleration-capacitance sensitivity of the variable area sensing unit of the shared mass block significantly lower than the differential variable spacing sensing unit of the shared mass block. When using the same readout circuit, due to the difference in acceleration-capacitance sensitivity, the acceleration-voltage sensitivity of the output voltage signal corresponding to the differential variable area sensing unit of the shared mass block is lower, corresponding to a higher circuit equivalent input noise, thereby causing the differential variable area sensing unit of the shared mass block to have a higher equivalent input noise as a whole. Finally, after the second step, the two mechanical sensing units respectively output high VRE low-noise capacitance signals C OUT3 High noise capacitor signal with low VRE C OUT4 , C OUT3 Corresponding to the capacitance output signal of the first mechanical sensing unit, C OUT4 The capacitance output signal of the second mechanical sensing unit corresponds to that of the differential variable spacing sensing unit 411 and the differential variable area sensing unit 412 of the shared mass block, which correspond to the first mechanical sensing unit 2002 and the second mechanical sensing unit 2003 .

[0082] Since the output signal forms of the two sensing units in this embodiment are Figure 2 Similar to the corresponding embodiment, for the anti-vibration signal fusion method of the differential variable spacing and variable area comb structure MEMS accelerometer of the shared mass block proposed in this embodiment, the circuit part of the signal conversion module and the compensation processing module in the execution process can be referred to Figure 2 Set up according to the corresponding embodiment.

[0083] In some possible implementations, when a high-range variable-spacing sensing unit of a shared mass block and a low-range variable-spacing sensing unit of a shared mass block are used as the first mechanical sensing unit and the second mechanical sensing unit, respectively, the following calculation method can be used to represent the capacitance output signal of the first mechanical sensing unit and the capacitance output signal of the second mechanical sensing unit:

[0084] Correspondingly, Figure 4 The schematic diagram of the structure of the mechanical module composed of the high-range variable distance sensing unit based on the shared mass block and the low-range variable distance sensing unit of the shared mass block is shown as an example. Figure 4As shown, the mechanical module 200 includes a fourth proof mass 502, a ninth fixed plate 503, a seventh movable plate 504, a tenth fixed plate 505, an eleventh fixed plate 506, an eighth movable plate 507, a twelfth fixed plate 508, and a fourth spring 509. The seventh movable plate 504 and the eighth movable plate 507 can move relative to the ninth fixed plate 503, the tenth fixed plate 505, the eleventh fixed plate 506, and the twelfth fixed plate 508 along with the fourth proof mass 502, and the fourth proof mass 502 is suspended by the fourth spring 509.

[0085] The ninth fixed electrode 503, the seventh movable electrode 504 and the tenth fixed electrode 505 constitute a low-range variable distance sensing unit 510 of a shared mass block. The seventh movable electrode 504 and the ninth fixed electrode 503 constitute the first sensing capacitor C of the low-range variable distance sensing unit of the shared mass block. SB1 The seventh movable electrode plate 504 and the tenth fixed electrode plate 505 constitute the second sensing capacitor C of the low-range variable distance sensing unit of the shared mass block. SB2 When the acceleration signal a is disturbed in = 0, the distance between the seventh movable electrode 504 and the ninth fixed electrode 503, 505 is d B ; When there is a disturbed acceleration signal a along the X axis in When the fourth detection mass block 502 is displaced, the seventh movable plate 504 is displaced, thereby making the first sensing capacitor C in the low-range variable spacing sensing unit of the shared mass block SB1 and the second sensing capacitor C SB2 The capacitance value changes, completing the conversion from acceleration signal to capacitance signal. Since the low-range sensing unit 510 is a differential variable-spacing sensing unit, the output capacitance C of the low-range variable-spacing sensing unit 510 of the shared mass block is obtained from formula (4). OUT5 It can be expressed as:

[0086]

[0087] Among them, C B It represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the low-range sensing unit, ε represents the dielectric constant, S B k represents the plate facing area of ​​the low-range variable-distance sensing unit with a shared mass block, B is the linear coefficient of the low-range variable-distance sensing unit of the shared mass block; the disturbed acceleration signal a in The relationship between the displacement ΔB of the movable plate in the low-range variable spacing sensing unit and the shared mass block is: ΔB = k B ·a in .

[0088] The eleventh fixed electrode plate 506, the twelfth fixed electrode plate 508 and the eighth movable electrode plate 507 form a high-range variable distance sensing unit 511 of a shared mass block. The eighth movable electrode plate 507 and the eleventh fixed electrode plate 506 form a first sensing capacitor C of the high-range variable distance sensing unit 511 of the shared mass block. SB1 ', the eighth movable electrode 507 and the twelfth fixed electrode 508 form a second sensing capacitor C SB2 ′. Disturbed acceleration signal a in = 0, the distance between the eighth movable electrode 507 and the eleventh fixed electrode 506, 508 is d B '; When there is a disturbed acceleration signal a along the X axis in When the fourth detection mass block 502 is displaced, the eighth movable plate 507 is displaced, thereby causing the first sensing capacitor C SB1 ′ and the second sensing capacitor C SB2 The capacitance of ′ changes, completing the conversion of acceleration signal to capacitance signal. Since the high-range variable spacing sensing unit 511 of the shared mass block is a differential variable spacing sensing unit, the output capacitance C of the high-range variable spacing sensing unit 511 of the shared mass block is obtained from formula (4). OUT6 It can be expressed as:

[0089]

[0090] Where ε represents the dielectric constant, S B ′ represents the area of ​​the first sensing capacitor or the second sensing capacitor in the high-range sensing unit of the shared mass block. According to the geometric relationship of the mechanical structure, S B ′=S B ;k B ′ is the linear coefficient of the high-range sensing unit of the shared mass block. According to the mechanical structure characteristics of the shared mass block, k B ′=k B ; Disturbed acceleration signal a in The relationship between the displacement ΔB′ of the movable plate in the high-range variable-distance sensing unit with the shared mass block is: ΔB′=k B ′·a in .

[0091] Since the distance d between the sensing capacitor plates of the high-range sensing unit is B ' is much larger than the distance d between the sensing capacitor plates of the low-range sensing unit B , according to formula (9) and (10), C OUT6 Middle a in 3 The coefficient of the term is much smaller than C OUT5 Middle a in 3The coefficient of the term is: compared with the low-range sensing unit of the shared mass block, the high-range sensing unit of the shared mass block can be approximately linear, so C OUT6 It can be approximated as:

[0092]

[0093] From formula (9) and formula (11), we can get the capacitance signal C output by the low-range sensing unit sharing the mass block: OUT5 In contrast, the high-range sensing unit of the shared mass block outputs a capacitance signal C OUT6 It has higher linearity, that is, lower VRE; however, the acceleration-capacitance sensitivity of the output signal of the high-range sensor unit is significantly lower than that of the low-range sensor unit. When the two sensor units use the same readout circuit, due to the difference in acceleration-capacitance sensitivity, the acceleration-voltage sensitivity of the output voltage signal corresponding to the high-range sensor unit is lower, corresponding to a higher circuit equivalent input noise, which in turn leads to a higher equivalent input noise for the high-range sensor unit as a whole. Finally, the two mechanical sensor units output high VRE and low noise capacitance signals C respectively. OUT5 High noise capacitor signal with low VRE C OUT6 , C OUT5 Corresponding to the capacitance output signal of the first mechanical sensing unit, C OUT6 The capacitance output signal of the second mechanical sensing unit corresponds to that of the low-range variable-distance sensing unit 510 and the high-range variable-distance sensing unit 511 of the shared mass block, which correspond to the first mechanical sensing unit 2002 and the second mechanical sensing unit 2003 .

[0094] Since the output signals of the first mechanical sensing unit and the second mechanical sensing unit in this embodiment are in the same form as Figure 2 Similar to the corresponding embodiment, for the anti-vibration signal fusion method of the high-range and low-range variable-pitch comb-tooth structure MEMS accelerometer with shared mass block proposed in this embodiment, the circuit part of the signal conversion module and the compensation processing module in the execution process can be referred to Figure 2 Set up according to the corresponding embodiment.

[0095] In some possible implementations, when a seesaw structure of a distal sensing unit and a proximal sensing unit is used as the first mechanical sensing unit and the second mechanical sensing unit, the following calculation method can be used to represent the capacitance output signal of the first mechanical sensing unit and the capacitance output signal of the second mechanical sensing unit:

[0096] Figure 5 The schematic diagram of the structure of the mechanical module composed of the far-end sensing unit and the near-end sensing unit based on the seesaw structure is shown as an example. Figure 5As shown, the mechanical module includes a fifth detection mass block 601, a first distal fixed plate 602, a first proximal fixed plate 603, a second proximal fixed plate 604 and a second distal fixed plate 605, wherein the first proximal fixed plate 603 and the second proximal fixed plate 604 are at the same distance from the mass block rotation axis 606, and the first distal fixed plate 602 and the second distal fixed plate 605 are at the same distance from the mass block rotation axis 606.

[0097] The fifth detection mass block 601, the first remote fixed plate 602 and the second remote fixed plate 605 constitute a remote sensing unit. SC1 , and the second remote fixed plate 605 form a second sensing capacitor C SC2 When the acceleration signal a is disturbed in = 0, the distances between the fifth detection mass block 601 and the first distal fixed plate 602 and the second distal fixed plate 605 are both d C ; When there is a disturbed acceleration signal a along the Z axis in When the fifth detection mass 601 rotates, the first sensing capacitor C SC1 and the second sensing capacitor C SC2 The capacitance value changes, completing the conversion from acceleration signal to capacitance signal. Since the remote sensing unit is a differential variable spacing sensing unit, the output capacitance C of the remote sensing unit is obtained from formula (4): OUT7 It can be expressed as:

[0098]

[0099] Among them, C C k represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the remote sensing unit, C is the linear coefficient of the remote sensing unit, the interference acceleration signal a in The relationship between the change in the distance between the fixed plate and the remote plate ΔC is: ΔC = k C ·a in .

[0100] The fifth detection mass block 601, the first proximal fixed plate 603 and the second proximal fixed plate 604 constitute a proximal sensing unit. The fifth detection mass block 601 and the first proximal fixed plate 603 constitute a first sensing capacitor C of the proximal sensing unit. SC1 ', the fifth detection mass block 601 and the second proximal fixed plate 604 constitute the second sensing capacitor C of the proximal sensing unit SC2 ′. When the acceleration signal a is disturbed in= 0, the distances between the fifth detection mass 601 and the first proximal fixed plate 603 and the second proximal fixed plate 604 are both d C '; d' can be obtained from the geometric relationship of the mechanical structure C =d C ; When there is a disturbed acceleration signal a along the Z axis in When the fifth detection mass 601 rotates, the first sensing capacitor C sC1 ′ and the second sensing capacitor C SC2 The capacitance of ′ changes, completing the conversion of acceleration signal to capacitance signal. Since the proximal sensing unit is a differential variable spacing sensing unit, the output capacitance C of the proximal sensing unit is obtained from formula (4): OUT8 It can be expressed as:

[0101]

[0102] Among them, C C ′ represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the proximal sensing unit. According to the geometric relationship of the mechanical structure, C C ′=C C ;k C ′ is the linear coefficient of the proximal sensing unit, and the interference acceleration signal a in The relationship between the change in the distance between the proximal fixed plate and ... C ′·a in .

[0103] Based on the difference in the position of the fixed plates of the two sensing units, there is a linear coefficient k of the remote sensing unit C Much larger than the linear coefficient k of the proximal sensing unit C ′, then C OUT8 Middle a in 3 The coefficient of the term is much smaller than C OUT7 Middle a in 3 The coefficient of the term is: the proximal sensing unit can be approximately linear compared to the distal sensing unit, then C OUT8 It can be approximated as:

[0104]

[0105] From formula (12) and formula (14), we can get the output capacitance signal C of the remote sensing unit: OUT7 In comparison, the proximal sensing unit outputs a capacitance signal C OUT8It has higher linearity, that is, lower VRE; however, the acceleration-capacitance sensitivity of the output signal of the proximal sensing unit is significantly lower than that of the output signal of the distal sensing unit. When the two sensing units use the same readout circuit, due to the difference in acceleration-capacitance sensitivity, the acceleration-voltage sensitivity of the output voltage signal corresponding to the proximal sensing unit is lower, corresponding to a higher circuit equivalent input noise, which in turn leads to a higher equivalent input noise of the proximal sensing unit as a whole. Finally, the two mechanical sensing units output high VRE and low noise capacitance signals C respectively. OUT7 High noise capacitor signal with low VRE C OUT8 . C OUT7 Corresponding to the capacitance output signal of the first mechanical sensing unit, C OUT8 The capacitance output signal of the second mechanical sensing unit corresponds to the capacitance output signal of the second mechanical sensing unit. That is, the remote sensing unit and the near-end sensing unit correspond to the first mechanical sensing unit 2002 and the second mechanical sensing unit 2003.

[0106] S103 , performing voltage signal conversion processing on the first output capacitor signal and the second output capacitor signal respectively, to obtain a first voltage output signal and a second voltage output signal accordingly.

[0107] It should be noted that the subsequent embodiments continue to use the mechanical module composed of the differential variable spacing capacitance sensor of the discrete mass block and the differential variable area capacitance sensor of the discrete mass block as an example to describe the data flow. However, for the mechanical module composed of the differential variable spacing sensing unit based on the shared mass block and the differential variable area sensing unit of the shared mass block, or the mechanical module composed of the high-range variable spacing sensing unit based on the shared mass block and the low-range variable spacing sensing unit of the shared mass block, or the mechanical module composed of the far-end sensing unit and the near-end sensing unit based on the seesaw structure, after obtaining the capacitance output signal of the first mechanical sensing unit and the capacitance output signal of the second mechanical sensing unit, the subsequent execution steps S103 and S104 are consistent with the processing process of the mechanical module composed of the differential variable spacing sensing unit based on the shared mass block and the differential variable area sensing unit of the shared mass block, and will not be repeated in the subsequent embodiments.

[0108] Optionally, S103 may specifically include:

[0109] The first output capacitor signal and the second output capacitor signal are converted into voltage signals respectively by using a CV conversion circuit to obtain a first voltage output signal and a second voltage output signal.

[0110] The first voltage output signal V1 is expressed as:

[0111]

[0112] The second voltage output signal V2 is expressed as:

[0113]

[0114] m represents the linear coefficient of the CV conversion circuit, C OUt1 represents the capacitance value of the first output capacitance signal, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the oppositely arranged fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, a in Represents the disturbed acceleration signal; C OUT2 represents the capacitance value of the second output capacitance signal, C0′ represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable area capacitance sensor of the discrete mass block, k′ represents the linear coefficient of the differential variable area capacitance sensor of the discrete mass block, and l0 represents the initial facing length between the movable plate and the corresponding fixed plate in the differential variable area capacitance sensor of the discrete mass block.

[0115] S104 , using the second voltage output signal to perform calibration and compensation processing on the nonlinear signal in the first voltage output signal to obtain a final acceleration output signal.

[0116] The final acceleration output signal is an acceleration signal with low noise and low VRE.

[0117] Optionally, S104 may specifically include:

[0118] Performing a cubic operation on the second voltage output signal to obtain a corresponding second voltage operation signal;

[0119] Calculating a nonlinear compensation coefficient based on the first voltage output signal and the second voltage operation signal;

[0120] The first voltage output signal is calibrated and compensated using the nonlinear compensation coefficient and the second voltage operation signal to obtain a final acceleration output signal.

[0121] In this embodiment, the second voltage operation signal V3 is expressed as:

[0122]

[0123] Transformation yields:

[0124]

[0125] Substituting formula (18) into formula (15), we can obtain:

[0126]

[0127] The nonlinear compensation coefficient can be obtained through the second term of formula (19).

[0128] The nonlinear compensation coefficient is expressed as:

[0129]

[0130] Wherein, s represents the nonlinear compensation coefficient, C0 represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable spacing capacitance sensor of the discrete mass block, m represents the linear coefficient of the CV conversion circuit, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the relatively set fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, C0′ represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable area capacitance sensor of the discrete mass block, k′ represents the linear coefficient of the differential variable area capacitance sensor of the discrete mass block, and l0 represents the initial facing length of the movable plate and the corresponding fixed plate in the differential variable area capacitance sensor of the discrete mass block.

[0131] Optionally, performing calibration and compensation processing on the first voltage output signal using the nonlinear compensation coefficient and the second voltage operation signal to obtain a final acceleration output signal includes:

[0132] Multiplying the nonlinear compensation coefficient and the second voltage operation signal to obtain a calibration compensation value;

[0133] The first voltage output signal is subtracted from the calibration compensation value to obtain a final acceleration output signal.

[0134] The final acceleration output signal is expressed as:

[0135]

[0136] Among them, V OUT represents the final acceleration output signal, V1 represents the first voltage output signal, v3 represents the second voltage operation signal, S represents the nonlinear compensation coefficient, m represents the linear coefficient of the CV conversion circuit, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, C0 represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the relatively set fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, a in Indicates the disturbed acceleration signal.

[0137] An embodiment of the present invention provides an anti-vibration signal fusion method for a MEMS accelerometer, comprising: obtaining a disturbed acceleration signal of the MEMS; the disturbed acceleration signal is an acceleration signal disturbed by vibration; using a first mechanical sensing unit and a second mechanical sensing unit in a mechanical module to perform signal conversion processing on the disturbed acceleration signal respectively, and correspondingly obtain a first output capacitance signal and a second output capacitance signal; the first mechanical sensing unit is a sensing unit with high VRE and low noise, and the second mechanical sensing unit is a sensing unit with low VRE and high noise; performing voltage signal conversion processing on the first output capacitance signal and the second output capacitance signal respectively, and correspondingly obtain a first voltage output signal and a second voltage output signal; using the second voltage output signal to perform calibration and compensation processing on a nonlinear signal in the first voltage output signal, and obtain a final acceleration output signal; the final acceleration output signal is an acceleration signal with low noise and low VRE. Since it is difficult for a single type of accelerometer to have the advantages of both "low VRE" and "low noise", the present invention uses a low VRE and high noise sensor unit output signal to compensate for a high VRE and low noise sensor unit output signal, ultimately obtaining a low VRE and low noise acceleration signal, thereby combining the advantages of the two acceleration sensor units and greatly improving the anti-vibration signal fusion system's measurement accuracy for acceleration signals in complex and changeable vibration environments. Secondly, since the anti-vibration signal fusion system used in the method of the present invention has a simple structure and avoids special mechanical structure design, it avoids an increase in cost and volume. In summary, the method of the present invention improves the measurement accuracy of acceleration signals while maintaining no increase in cost and volume.

[0138] Based on the same inventive concept, an embodiment of the present invention further provides an anti-vibration signal fusion system for a MEMS accelerometer. Figure 6 A structural diagram of an anti-vibration signal fusion system for a MEMS accelerometer provided in an embodiment of the present invention is shown in FIG. Figure 6 As shown, it includes: an acquisition module 100, a mechanical module 200, a signal conversion module 300 and a compensation processing module 400; the compensation processing module 400 includes: a first operation circuit 4005 and a second operation circuit 4006;

[0139] The acquisition module 100 is used to: acquire a disturbed acceleration signal of the MEMS; the disturbed acceleration signal is an acceleration signal disturbed by vibration;

[0140] The mechanical module 200 is used to: use the first mechanical sensing unit 2002 and the second mechanical sensing unit 2003 in the mechanical module to perform signal conversion processing on the interference acceleration signal, and obtain a first output capacitance signal C OUT1 and the second output capacitance signal C OUT2The first mechanical sensing unit 2002 is a sensing unit with high VRE and low noise, and the second mechanical sensing unit 2003 is a sensing unit with low VRE and high noise;

[0141] The signal conversion module 300 is used to perform voltage signal conversion processing on the first output capacitor signal and the second output capacitor signal respectively, and obtain a first voltage output signal and a second voltage output signal accordingly;

[0142] The first operation circuit 4005 and the second operation circuit 4006 are used to: use the second voltage output signal to calibrate and compensate the nonlinear signal in the first voltage output signal to obtain a final acceleration output signal; the final acceleration output signal is an acceleration signal with low noise and low VRE.

[0143] Optionally, the first mechanical sensing unit is a differential variable spacing capacitance sensor of a discrete mass block; the second mechanical sensing unit is a differential variable area capacitance sensor of a discrete mass block; the differential variable spacing capacitance sensor of the discrete mass block and the differential variable area capacitance sensor of the discrete mass block are both upper and lower symmetrical structures;

[0144] The differential variable spacing capacitance sensor of the discrete mass block and the differential variable area capacitance sensor of the discrete mass block are arranged on the same substrate in the mechanical module in the same direction.

[0145] It should be noted that the terms "first," "second," and the like are used to distinguish similar objects and are not necessarily used to describe a particular order or precedence. It should be understood that the terms used in this manner are interchangeable where appropriate, so that the embodiments of the present invention described herein can be implemented in sequences other than those illustrated or described herein. The embodiments described in the following exemplary embodiments do not represent all embodiments consistent with the present invention. Instead, they are merely examples of devices and methods consistent with some aspects of the present invention.

[0146] In the description of this specification, the reference terms "one embodiment," "some embodiments," "examples," "specific examples," or "some examples" mean that the specific features or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features or characteristics described can be combined in any suitable manner in any one or more embodiments or examples. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification.

[0147] Although the present invention is described herein in conjunction with various embodiments, in the process of implementing the claimed invention, those skilled in the art can understand and implement other variations of the above-mentioned disclosed embodiments by viewing the drawings and the disclosed content. In the description of this specification, the word "comprising" does not exclude other components or steps, "one" or "a" does not exclude multiple situations, and the meaning of "multiple" is two or more, unless otherwise clearly and specifically defined. In addition, certain measures are recorded in different embodiments, but this does not mean that these measures cannot be combined to produce good results.

[0148] The above is a further detailed description of the present invention in conjunction with specific preferred embodiments, and the specific implementation of the present invention cannot be considered to be limited to these descriptions. For those skilled in the art of the present invention, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all of these should be considered to fall within the scope of protection of the present invention.

Claims

1. A method for fusion of anti-vibration signals of MEMS accelerometer, characterized in that: include: Acquiring a disturbed acceleration signal of the MEMS; the disturbed acceleration signal is an acceleration signal disturbed by vibration; performing signal conversion processing on the interfered acceleration signal using a first mechanical sensing unit and a second mechanical sensing unit in the mechanical module, respectively, to obtain a first output capacitance signal and a second output capacitance signal; the first mechanical sensing unit is a sensing unit with high VRE and low noise, and the second mechanical sensing unit is a sensing unit with low VRE and high noise; performing voltage signal conversion processing on the first output capacitor signal and the second output capacitor signal respectively, to obtain a first voltage output signal and a second voltage output signal accordingly; The nonlinear signal in the first voltage output signal is calibrated and compensated using the second voltage output signal to obtain a final acceleration output signal; the final acceleration output signal is an acceleration signal with low noise and low VRE.

2. The anti-vibration signal fusion method of MEMS accelerometer according to claim 1, characterized in that: The first mechanical sensing unit is a differential variable spacing capacitance sensor of a discrete mass block; the second mechanical sensing unit is a differential variable area capacitance sensor of a discrete mass block.

3. The anti-vibration signal fusion method of MEMS accelerometer according to claim 1, characterized in that: The performing voltage signal conversion processing on the first output capacitor signal and the second output capacitor signal respectively to obtain a first voltage output signal and a second voltage output signal accordingly includes: The first output capacitor signal and the second output capacitor signal are converted into voltage signals respectively by using a CV conversion circuit to obtain the first voltage output signal and the second voltage output signal accordingly.

4. The anti-vibration signal fusion method of MEMS accelerometer according to claim 1, characterized in that: The first output capacitance signal is expressed as: Among them, C OUT1 represents the capacitance value of the first output capacitance signal, C0 represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable spacing capacitance sensor of the discrete mass block, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the oppositely arranged fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, a in Indicates the disturbed acceleration signal; The second output capacitance signal is expressed as: Among them, C OUT2 Represents the capacitance value of the second output capacitance signal, C0 ′ k represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable area capacitance sensor of the discrete mass block, ′ represents the linear coefficient of the differential variable area capacitance sensor of the discrete mass block, and l0 represents the initial facing length between the movable plate and the corresponding fixed plate in the differential variable area capacitance sensor of the discrete mass block.

5. The anti-vibration signal fusion method of MEMS accelerometer according to claim 1, characterized in that: The step of using the second voltage output signal to calibrate and compensate the nonlinear signal in the first voltage output signal to obtain a final acceleration output signal includes: Performing a cubic operation on the second voltage output signal to obtain a corresponding second voltage operation signal; Calculating a nonlinear compensation coefficient based on the first voltage output signal and the second voltage operation signal; The first voltage output signal is calibrated and compensated using the nonlinear compensation coefficient and the second voltage operation signal to obtain the final acceleration output signal.

6. The anti-vibration signal fusion method of MEMS accelerometer according to claim 5, characterized in that: The nonlinear compensation coefficient is expressed as: Wherein, s represents the nonlinear compensation coefficient, C0 represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable spacing capacitance sensor of the discrete mass block, m represents the linear coefficient of the CV conversion circuit, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the relatively set fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, C0 ′ k represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable area capacitance sensor of the discrete mass block, ′ represents the linear coefficient of the differential variable area capacitance sensor of the discrete mass block, and l0 represents the initial facing length between the movable plate and the corresponding fixed plate in the differential variable area capacitance sensor of the discrete mass block.

7. The anti-vibration signal fusion method of MEMS accelerometer according to claim 5, characterized in that: The step of performing calibration and compensation processing on the first voltage output signal by using the nonlinear compensation coefficient and the second voltage operation signal to obtain the final acceleration output signal includes: multiplying the nonlinear compensation coefficient and the second voltage operation signal to obtain a calibration compensation value; Subtracting the first voltage output signal from the calibration compensation value to obtain the final acceleration output signal; The final acceleration output signal is expressed as: Among them, V ′UT represents the final acceleration output signal, V1 represents the first voltage output signal, V3 represents the second voltage operation signal, s represents the nonlinear compensation coefficient, m represents the linear coefficient of the CV conversion circuit, k represents the linear coefficient of the differential variable spacing capacitance sensor of the discrete mass block, C0 represents the static capacitance value of the first sensing capacitor or the second sensing capacitor in the differential variable spacing capacitance sensor of the discrete mass block, d0 represents the distance between the movable plate and the relatively set fixed plate in the differential variable spacing capacitance sensor of the discrete mass block, a in Indicates the disturbed acceleration signal.

8. A MEMS accelerometer anti-vibration signal fusion system, characterized in that: include: Acquisition module, mechanical module, signal conversion module and compensation processing module; The compensation processing module includes: a first operation circuit and a second operation circuit; The acquisition module is used to: acquire a disturbed acceleration signal of the MEMS; the disturbed acceleration signal is an acceleration signal disturbed by vibration; The mechanical module is configured to: use a first mechanical sensing unit and a second mechanical sensing unit in the mechanical module to perform signal conversion processing on the interfered acceleration signal, respectively, to obtain a first output capacitance signal and a second output capacitance signal; the first mechanical sensing unit is a sensing unit with high VRE and low noise, and the second mechanical sensing unit is a sensing unit with low VRE and high noise; The signal conversion module is used to: perform voltage signal conversion processing on the first output capacitor signal and the second output capacitor signal respectively, and obtain a first voltage output signal and a second voltage output signal accordingly; The first operation circuit and the second operation circuit are used to: use the second voltage output signal to calibrate and compensate the nonlinear signal in the first voltage output signal to obtain a final acceleration output signal; the final acceleration output signal is an acceleration signal with low noise and low VRE.

9. The anti-vibration signal fusion system of the MEMS accelerometer according to claim 8, characterized in that: The first mechanical sensing unit is a differential variable spacing capacitance sensor of a discrete mass block; the second mechanical sensing unit is a differential variable area capacitance sensor of a discrete mass block; the differential variable spacing capacitance sensor of the discrete mass block and the differential variable area capacitance sensor of the discrete mass block are both symmetrical in structure; The differential variable pitch capacitance sensor of the discrete mass block and the differential variable area capacitance sensor of the discrete mass block are arranged on the same substrate in the mechanical module in the same direction.

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