MEMS sensor self-calibration system and self-calibration method

Abstract

The present application discloses a MEMS sensor self-calibration system and a self-calibration method, which relates to the field of sensor detection. The excitation signal module of the system is connected to the MCU, and the excitation signal is output according to the control signal and sent to the inside of the sensor to change the capacitance value of the comb capacitance inside the sensor; the MCU collects the signal value of the sensor and performs signal correction output; the MCU obtains the calibration data output by each excitation signal under the corresponding comb capacitance value, and compares the linearity with the actual signal value under the action of the excitation signal, calculates and updates the self-test gain of the sensor; in the normal working mode, the MCU obtains the measured signal value of the sensor, and calculates the output calibration signal value based on the updated self-test gain. The system can realize automatic performance evaluation and calibration during the working process of the sensor, and can ensure the accuracy and stability of the sensor output data without external equipment or manual intervention.

Description

Technical Field

[0001] The embodiments of the present application relate to the field of sensor detection, and in particular to a MEMS sensor self-calibration system and self-calibration method. Background Art

[0002] With the rapid development of science and technology, micro-electromechanical system (MEMS) sensors, as key components of miniaturization, integration and intelligence, have shown broad application prospects in many fields such as consumer electronics, automotive electronics, industrial automation, aerospace, and medical health. Among them, MEMS sensors are important tools for monitoring the motion state, posture changes and vibration analysis of objects. The stability and accuracy of their performance are directly related to the reliability and accuracy of the entire system.

[0003] In practical applications, MEMS sensors are often affected by many factors such as ambient temperature changes, mechanical stress, electromagnetic interference, and aging effects caused by long-term use. These factors may cause drift or distortion of the sensor output signal, thereby affecting its measurement accuracy. Traditional sensor calibration methods usually need to be performed in a specific laboratory environment, which is not only time-consuming and labor-intensive, but also difficult to reflect the actual performance changes of the sensor in a complex and changeable working environment in real time. In view of this, it is particularly important to develop a method or device that can realize self-test and self-calibration of MEMS sensors. Summary of the invention

[0004] The embodiments of the present application provide a MEMS sensor self-calibration system and a self-calibration method to solve the problem that the MEMS sensor cannot self-calibrate and self-check.

[0005] On the one hand, the present application provides a MEMS sensor self-calibration system, the system comprising an excitation signal module, a MEMS sensor and an MCU chip; the excitation signal module is connected to the MCU chip, and outputs different excitation signals according to a control signal, and the excitation signal is sent to the MEMS sensor to control the capacitance value of the comb capacitor inside the MEMS sensor; the MCU chip collects the signal value of the MEMS sensor and performs signal correction output;

[0006] The MCU obtains calibration data output by each excitation signal under the corresponding comb capacitance value, and compares the linearity with the actual signal value under the action of the excitation signal, and calculates and updates the self-test gain of the MEMS sensor;

[0007] In the normal working mode, the MCU obtains the measured signal value of the MEMS sensor, and calculates the output calibration signal value based on the updated self-test gain.

[0008] Specifically, the excitation signal module includes multiple groups of excitation signal sources with gradient changes and switching circuits. All excitation signal sources are connected to corresponding signal switches in the switching circuit. The convergence end of all signal switches is the excitation signal output end and is connected to the MEMS sensor; the switching circuit controls the output of the target excitation signal based on the control signal of the MCU chip.

[0009] Specifically, the MCU chip is provided with an excitation signal control module and a sequential logic state machine. When the system is powered on and initialized, the sequential logic state machine controls the excitation signal control module to output a control signal according to the set sequential logic and collects output data.

[0010] Specifically, the MCU chip also includes a differential operational amplifier module, an ADC conversion module and a factory gain module;

[0011] The differential operational amplifier module is connected to the signal output end of the MEMS sensor, and performs data conversion through the ADC conversion module to obtain measured data;

[0012] The factory gain module stores the factory gain obtained by calibrating the sensor sensitivity coefficient of the MEMS sensor under the original self-test gain; the factory gain module obtains the calibration signal value according to the product of the factory gain and the measured data.

[0013] Specifically, the MCU chip also includes a linear calculation circuit and a self-test gain module. The linear calculation circuit extracts calibration data based on a sequential logic state machine, collects actual signal values, and performs linearity comparison and calculates self-test gain values ​​based on the calibration data and the actual signal values; the calibration data is set at the factory stage and burned into the MCU chip;

[0014] The self-test gain module updates the self-test gain value based on the output of the linear calculation circuit; in the normal working mode, the calibration signal value is output based on the product of the actual signal value and the updated self-test gain value.

[0015] On the other hand, the present application provides a MEMS sensor, which is used in the MEMS sensor self-calibration system described in the above aspects, including a comb-tooth spring member and a plurality of comb-tooth fixing members, the comb-tooth fixing members are distributed on both sides of the comb-tooth spring member; the comb-tooth fixing members and the comb-tooth spring member have comb-tooth portions that are cross-distributed to form a comb-tooth capacitor; the comb-tooth fixing members converge at the tail end to form an electrical signal output terminal as a signal value output by the MEMS sensor;

[0016] Magnetic heads are installed at both ends of the comb handle spring part, and a micro electromagnet is set at a position far away from the magnetic head, and a winding is wound around the micro electromagnet; the two windings respectively input excitation signals, and the comb tooth spring part is controlled to produce displacement under the action of electromagnetic force, thereby changing the capacitance value of the comb tooth capacitor inside the MEMS sensor.

[0017] Specifically, the comb handle spring member includes an axial comb handle and comb tooth structures symmetrically distributed on both sides of the comb handle;

[0018] Insulating structural members with preset lengths are respectively installed at both ends of the comb handle, and the magnetic head is installed at the end of the insulating structural member.

[0019] In another aspect, the present application provides a MEMS sensor self-calibration method, the method being used to calibrate the MEMS sensor described in the above aspects, the method comprising:

[0020] After power-on initialization, the target excitation signal is input to the two winding ends of the MEMS sensor, and the calibration signal value corresponding to the target excitation signal is collected through the MCU chip;

[0021] Compare the actual signal value collected with the pre-stored calibration signal value to calculate the drift error;

[0022] In response to the drift error being within a preset error range, performing a linearity analysis on the calibration signal value, calculating and obtaining a dynamic self-test gain value, and updating the value;

[0023] Entering the normal working measurement mode, the product of the measured signal value collected by the MEMS sensor and the updated self-test gain value is determined as the calibration signal value and output.

[0024] Specifically, N groups of target excitation signals with gradient changes are input to the MEMS sensor in sequence, and the actual signal values ​​of the corresponding outputs are collected;

[0025] Obtain the actual signal values ​​collected under the action of N groups of target excitation signals and the corresponding pre-stored calibration data, compare them, and calculate N groups of drift errors; when all N groups of drift errors are within the set error range, start the data calibration mechanism; when there is at least one group of drift errors exceeding the error range, perform error processing.

[0026] Specifically, when the data calibration mechanism is started, a dynamic self-test gain value is calculated based on the ratio of the calibration data to the actual signal value;

[0027] The calculated N groups of self-test gain values ​​are compared with the factory gain values ​​respectively, and the N groups of gain errors are calculated. When the N groups of gain errors are all within the set error range, the average of the N groups of self-test gains is determined as the updated self-test gain; when there is at least one group of gain errors exceeding the error range or above, an error processing is performed.

[0028] The beneficial effects of the technical solution provided by the embodiment of the present application include at least: by adding a micro electromagnet structure to both ends of the comb spring member inside the traditional sensor, the comb capacitance can be changed by applying an excitation signal externally, and the sensor can automatically perform performance evaluation and calibration during operation with the cooperation of the built-in self-detection circuit and the micro MCU chip, and the accuracy and stability of the sensor output data can be ensured without external equipment or manual intervention. This can not only significantly reduce the maintenance cost of the sensor and improve the automation level of the system, but also significantly enhance the market competitiveness of the product and meet the urgent needs of modern industry for high-precision and high-reliability sensors. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 It is a structural schematic diagram of a MEMS sensor for self-test provided by the present application;

[0030] Figure 2 It is a system schematic diagram of the MEMS sensor self-test system provided by the present application;

[0031] Figure 3 is a flow chart of the MEMS sensor self-calibration method provided by the present application;

[0032] Figure 4 It is a flow chart of the self-calibration method based on MEMS sensor;

[0033] Figure 5 A comparison diagram of the expected data under the action of the excitation signal and the actual data after drift is shown;

[0034] Figure 6 An algorithm flow chart of the MEMS sensor self-calibration method is shown. DETAILED DESCRIPTION

[0035] In order to make the objectives, technical solutions and advantages of the present application clearer, the implementation methods of the present application will be further described in detail below with reference to the accompanying drawings.

[0036] The term "multiple" as used herein refers to two or more than two. "And / or" describes the relationship between related objects, indicating that three relationships can exist. For example, A and / or B can mean: A exists alone, A and B exist at the same time, and B exists alone. The character " / " generally indicates that the related objects are in an "or" relationship.

[0037] Figure 1 This is a schematic diagram of the structure of a MEMS sensor with a self-test function provided by the present application. A conventional MEMS sensor is generally composed of a comb-tooth fixing member and a comb-tooth spring member. The comb-tooth parts of the comb-tooth fixing member and the comb-tooth spring member are arranged alternately to form an internal comb-tooth capacitor. The present application makes improvements on this basis, such as Figure 1It is shown that the comb-tooth fixing parts are distributed on both sides of the comb-tooth spring parts, and the comb-tooth parts of the comb-tooth fixing parts and the comb-tooth spring parts are cross-distributed to form comb-tooth capacitors, which converge at the tail end of the comb-tooth fixing parts to form electrical signal output terminals, namely PAD1 and PAD2. Correspondingly, electrical signal output terminals, namely PAD3-PAD6, are also provided on the comb-tooth parts of the comb-tooth spring parts. The PADs of all spring structures are connected together, the PADs of the two fixing parts output two PADs, and three wires input two differential signals, which are finally output as the signal value output by the MEMS sensor. The Value output by the final sensor is obtained through external lead-out.

[0038] Because the spacing between two adjacent structures of the comb teeth will form a capacitance effect, when the object is subjected to a force in a certain direction, the object will generate acceleration, driving the comb tooth spring to displace, causing the comb tooth capacitance to change, and an electrical signal PAD will be generated at the position of the comb tooth fixing part PAD, so that the acceleration value can be further obtained by measuring the capacitance change value. That is, the measurement data is obtained at the terminal position of PAD1-PAD6.

[0039] The present application adds a positive / negative end excitation signal structure to the conventional acceleration sensor structure, that is, magnetic heads are additionally installed at the two ends of the comb-tooth spring member, and a micro-electromagnet is arranged at a position away from the magnetic head, and a winding is wound around the micro-electromagnet; the two windings respectively input excitation signals, and under the action of electromagnetic force, the micro-electromagnet attracts the magnetic head, driving the comb-tooth spring member to produce displacement, and actively changing the capacitance value of the comb-tooth capacitor inside the MEMS sensor.

[0040] Optionally, the two terminals of the winding on the two-end micro electromagnet are respectively a power supply terminal and an excitation signal terminal. Figure 1 The upper winding in the middle is the positive terminal and one excitation signal input, and the lower winding is the positive and negative poles and another excitation signal input. When different levels of excitation signals are applied to the micro electromagnet, the electromagnet will generate a certain suction force F on the magnetic head. Different levels of suction force F will produce different levels of deformation of the comb spring, thereby producing the effect of measuring capacitance changes.

[0041] The MEMS structure generates fixed suction force F1 of different levels and directions under different excitation signals, which is used to correct the drift of the comb spring component due to the inconsistent elastic coefficient in different environments, and finally realize the process of power-on self-test linearity and sensitivity. In the normal working mode, the excitation signal is no longer applied, and the sensor itself is used to sense the force F applied by the external environment, and the change value of the deformation capacitance of the spring structure (PAD signal value) is collected to obtain the acceleration value.

[0042] Based on the above improved MEMS sensor, this application designs Figure 2The MEMS sensor self-calibration system shown in the figure includes an improved MEMS sensor structure, an excitation signal module and a self-test MCU chip. The output end of the excitation signal module is connected to the two excitation signal terminals of the MEMS sensor, and the comb-tooth fixing part of the MEMS sensor normally outputs the measurement signal value, which is input to the MCU chip. The MCU performs data measurement and verification, and when the measured sensor value deviates, it can correct the output accurate value in time. The above system can form a self-calibration composite MEMS sensor device, which can be used in acceleration detection equipment such as vehicles.

[0043] In some embodiments, in order to achieve more accurate measurement and correction, a plurality of groups of excitation signal sources and switching circuits with gradient changes can be set in the excitation signal module. All excitation signal sources are connected to the corresponding signal switches in the switching circuit. The convergence end of all signal switches is the excitation signal output end and is connected to the MEMS sensor. The switching circuit controls the output of the target excitation signal based on the control signal of the MCU chip.

[0044] by Figure 2 The 7 excitation signal sources with gradient changes in the sensor are used as an example to illustrate. Specifically, they can be divided into normal working excitation signal, primary excitation signal (including positive and negative terminals), secondary excitation signal and tertiary excitation signal. The signal value changes in gradient and is best set to cover the full range of the sensor, so that calibration can be ensured within the entire range.

[0045] Optionally, an excitation signal control module and a timing logic state machine can be set in the MCU chip. When the system is powered on and initialized, the excitation signal control module is controlled to output a control signal (selection signal) according to the timing logic of the state machine control system, select a certain excitation signal source to output, collect output data, and control the processing process of other modules.

[0046] The MCU chip also includes a differential op amp module, an ADC conversion module, and a factory gain module; the differential op amp module is connected to the signal output end of the MEMS sensor, and performs data conversion through the ADC conversion module to obtain the measured data ADC_Value. The factory gain module stores the factory gain obtained by calibrating the sensor sensitivity coefficient of the MEMS sensor under the original self-test gain. The factory gain module obtains the calibration signal value according to the product of the factory gain and the measured data.

[0047] Here we explain that the data Samp_Result collected and output by the MEMS sensor can be expressed using the following formula:

[0048] Samp_Result=ADC_Value*F_GAIN*S_GAIN

[0049] The ADC_Value in the above formula is the data converted by the ADC conversion module, and F_GAIN (factory gain) is the value obtained by calibrating the sensor sensitivity coefficient by setting S_GAIN (self-test gain) to the default coefficient of 1 during the factory calibration phase. In other words, under ideal conditions, the factory sensor S_GAIN = 1. After leaving the factory, the F_GAIN value will be written into the factory gain module (Factory GAIN, x F_GAIN) for protection and will not be changed by any factors, so this application does not consider this value.

[0050] Figure 3 The linear diagram of vehicle acceleration and measured acceleration is shown as an example. Under ideal conditions, the vehicle acceleration is equal to the actual measured acceleration, and the linear slope K = 1. However, in harsh scenarios and due to old replacement, the elastic coefficient of the comb spring inside the sensor changes, and the linear slope K will increase or decrease, which is reflected in the above formula, which is equivalent to a change in the value of S_GAIN. This application is to calculate and update the latest value of S_GAIN.

[0051] To solve the above problems, a linear calculation circuit and a self-test gain module are set inside the MCU chip. The linear calculation circuit is controlled by the sequential logic control center, extracts calibration data based on the sequential logic state machine, collects actual signal values, and performs linearity comparison and calculates self-test gain values ​​based on the calibration data and actual signal values. The calibration data here is set at the factory stage and burned into the MCU chip, and this data is also unmodifiable. Figure 2 For the 7 sets of gradient data shown in the figure, in the absence of other external forces, the corresponding excitation signals are output to the two windings of the improved MEMS sensor respectively to control them to form the target comb capacitance, and then the measured Samp_Result value (the data at the factory stage must be accurate) is determined as the calibration data.

[0052] The self-test gain module (Self-text GAIN, x S_GAIN) updates the self-test gain value based on the output of the linear calculation circuit. Because the S_GAIN value is factory defaulted to 1, the above formula can actually be expressed as:

[0053] Samp_Result=ADC_Value*F_GAIN

[0054] When S_GAIN deviates, the actual signal value Samp_Result obtained after the input excitation signal also deviates, while the stored calibration data H (expected data) is accurate. Therefore, there is the following relationship between Samp_Result and calibration data:

[0055] H=Samp_Result*S_GAIN'

[0056] S_GAIN' represents the updated self-test gain, so S_GAIN'=H / Samp_Result.

[0057] After S_GAIN' is calculated and determined, it is updated to the self-test gain module. In the normal working mode after the subsequent self-test is completed, the actual signal values ​​output by all MEMS sensors need to be proportionally increased by the factor of S_GAIN', that is, the calibration signal output by the MCU = S_GAIN'*actual signal value.

[0058] Based on the above-mentioned MEMS sensor self-test system, the present application provides a MEMS sensor self-calibration method, such as Figure 4 : is a flow chart of the MEMS sensor self-calibration method, comprising the following steps:

[0059] S1, power-on initialization, input the target excitation signal to the two winding ends of the MEMS sensor, and collect the calibration signal value corresponding to the target excitation signal through the MCU chip;

[0060] In this stage, when the sensor is powered on and in the 0g state, the MEMS sensor is powered on and self-tested, and the value of the excitation signal is adjusted in sequence according to the control logic of the state machine. In a possible implementation, N groups of target excitation signals with gradient changes are input to the MEMS sensor in sequence, and the actual signal values ​​of the corresponding outputs are collected.

[0061] S2, comparing the actual signal value collected with the pre-stored calibration signal value to calculate the drift error;

[0062] For N groups of excitation signal sources, the actual signal values ​​collected under the action of N groups of target excitation signals and the corresponding pre-stored calibration data are obtained and compared to calculate N groups of drift errors. When all N groups of drift errors are within the set error range (for example, 30% of the expected data), the data calibration mechanism is started; when there is at least one group of drift errors exceeding the error range (for example, 30% of the expected data), an error processing is performed.

[0063] Figure 5 A comparison chart between the expected data under the action of the excitation signal and the actual data after drift is shown. When the error range of any one or more of the 7 groups of data exceeds the expected data by 30% or more, it means that the environment in which the sensor equipment is located cannot be accurately measured, or it is severely aged and damaged, and an error is reported.

[0064] Figure 6 The algorithm flow chart of the MEMS sensor self-calibration method is shown. For data exceeding the drift error range, the self-check Error is directly output. For data satisfying the drift error, the subsequent S3 step is performed.

[0065] S3, in response to the drift error being within the preset error range, performing linearity analysis on the calibration signal value, calculating and obtaining a dynamic self-test gain value, and updating the value;

[0066] Linearity analysis is calculated according to the aforementioned linear calculation formula, and the self-test gain value is calculated by the ratio of the calibration data to Samp_Result. For N groups of excitation signal sources, the calculated N groups of self-test gain values ​​are compared with the factory gain values, and the N groups of gain errors are calculated. When the N groups of gain errors are within the set error range (for example, the default self-test gain data of 10% is taken as an example), the average of the N groups of self-test gains is determined as the updated self-test gain. When there is at least one group of gain errors exceeding the error range (for example, the default self-test gain data of 10% is taken as an example), the self-test Error is directly output.

[0067] S4, entering the normal working measurement mode, determining the product of the measured signal value collected by the MEMS sensor and the updated self-test gain value as the calibration signal value and outputting it.

[0068] In summary, the beneficial effects brought by the present application include the following: by adding a micro electromagnet structure to both ends of the comb spring member inside the traditional sensor, an excitation signal can be applied externally to change the comb capacitance, and the calibration data of the ideal state sensor when it is powered on and in the 0g state can be recorded with the cooperation of the built-in self-detection circuit and the micro MCU chip. During the power-on self-test, the output data under the action of the gradient excitation signal is collected to complete the MEMS power-on self-test process. The sensor can automatically perform performance evaluation and calibration during the working process, and the accuracy and stability of the sensor output data can be ensured without external equipment or manual intervention. This can not only significantly reduce the maintenance cost of the sensor and improve the automation level of the system, but also significantly enhance the market competitiveness of the product, and meet the urgent needs of modern industry for high-precision and high-reliability sensors.

[0069] Furthermore, the present application also provides a computer device, comprising a processor and a memory, wherein the memory stores at least one instruction, at least one program, a code set or an instruction set, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by the processor to implement the MEMS sensor self-calibration method described in any of the above embodiments.

[0070] Furthermore, the present application also provides a computer-readable storage medium, in which at least one instruction, at least one program, a code set or an instruction set is stored, and the at least one instruction, the at least one program, the code set or the instruction set is loaded and executed by a processor to implement the MEMS sensor self-calibration method described in any of the above embodiments.

[0071] This specific embodiment is merely an explanation of the present invention and is not a limitation of the present invention. After reading this specification, those skilled in the art may make non-creative modifications to the present embodiment as needed. However, as long as they are within the scope of the claims of the present invention, they are protected by the patent law.

Claims

1. A MEMS sensor self-calibration system, characterized in that: The system includes an excitation signal module, a MEMS sensor and an MCU chip; the MEMS sensor includes a comb-tooth spring member and a plurality of comb-tooth fixing members, the comb-tooth fixing members are distributed on both sides of the comb-tooth spring member; the comb-tooth fixing members and the comb-tooth spring member have comb-tooth portions that are cross-distributed to form a comb-tooth capacitor; the electrical signal is gathered at the tail ends of all the comb teeth to be output as the signal value output by the MEMS sensor; Magnetic heads are installed at both ends of the comb-tooth spring member, and a micro electromagnet is arranged at a position far away from the magnetic head, and a winding is wound around the micro electromagnet; the two windings input excitation signals respectively, and the comb-tooth spring member is controlled to generate displacement under the action of electromagnetic force, thereby changing the capacitance value of the comb-tooth capacitor inside the MEMS sensor; The excitation signal module is connected to the MCU chip, and includes multiple groups of excitation signal sources and switch circuits with gradient changes. All excitation signal sources are connected to corresponding signal switches in the switch circuit. The convergence end of all signal switches is the excitation signal output end, and is connected to the MEMS sensor; In the calibration mode, the switch circuit controls the output of different excitation signals based on the control signal of the MCU chip. The excitation signal is sent to the MEMS sensor to control the capacitance value of the comb capacitance inside the MEMS sensor. The MCU chip collects the signal value of the MEMS sensor and performs signal correction output. The MCU obtains the calibration data output by each excitation signal under the corresponding comb capacitance value, and compares the linearity with the actual signal value under the action of the excitation signal, calculates and updates the self-test gain of the MEMS sensor; the formula is as follows: S_GAIN'=H / Samp_Result H represents calibration data, which is set and burned into the MCU chip at the factory stage; Samp_Result represents the actual signal value; S_GAIN' represents the updated self-test gain; In the normal working mode, the MCU obtains the measured signal value of the MEMS sensor, and calculates the output calibration signal value based on the updated self-test gain.

2. The MEMS sensor self-calibration system according to claim 1, characterized in that: The MCU chip is provided with an excitation signal control module and a sequential logic state machine. When the system is powered on and initialized, the sequential logic state machine controls the excitation signal control module to output a control signal according to the set sequential logic and collects output data.

3. The MEMS sensor self-calibration system according to claim 2, characterized in that: The MCU chip also includes a differential operational amplifier module, an ADC conversion module and a factory gain module; The differential operational amplifier module is connected to the signal output end of the MEMS sensor, and performs data conversion through the ADC conversion module to obtain measured data; The factory gain module stores the factory gain obtained by calibrating the sensor sensitivity coefficient of the MEMS sensor under the original self-test gain; the factory gain module obtains the calibration signal value according to the product of the factory gain and the measured data.

4. The MEMS sensor self-calibration system according to claim 3, characterized in that: The MCU chip also includes a linear calculation circuit and a self-test gain module. The linear calculation circuit extracts calibration data based on a sequential logic state machine, collects actual signal values, performs linearity comparison and calculates self-test gain values ​​based on the calibration data and the actual signal values; The self-test gain module updates the self-test gain value based on the output of the linear calculation circuit; In normal operating mode, a calibration signal value is output based on the product of the actual signal value and the updated self-test gain value.

5. The MEMS sensor self-calibration system according to claim 1, characterized in that: The comb teeth spring member comprises an axial comb handle and comb teeth structures symmetrically distributed on both sides of the comb handle; Insulating structural members with preset lengths are respectively installed at both ends of the comb handle, and the magnetic head is installed at the end of the insulating structural member.

6. A MEMS sensor self-calibration method, characterized in that: The method is used to calibrate the MEMS sensor self-calibration system according to claim 1, and the method comprises: After power-on initialization, the target excitation signal is input to the two winding ends of the MEMS sensor, and the calibration signal value corresponding to the target excitation signal is collected through the MCU chip; Compare the actual signal value collected with the pre-stored calibration signal value to calculate the drift error; In response to the drift error being within a preset error range, performing a linearity analysis on the calibration signal value, calculating and obtaining a dynamic self-test gain value, and updating the value; Entering the normal working measurement mode, the product of the measured signal value collected by the MEMS sensor and the updated self-test gain value is determined as the calibration signal value and output.

7. The method according to claim 6, characterized in that Input N groups of target excitation signals with gradient changes to the MEMS sensor in sequence, and collect the actual signal values ​​of the corresponding outputs; Obtain the actual signal values ​​collected under the action of N groups of target excitation signals and the corresponding pre-stored calibration data, compare them, and calculate N groups of drift errors; when all N groups of drift errors are within the set error range, start the data calibration mechanism; when there is at least one group of drift errors exceeding the error range, perform error processing.

8. The method according to claim 7, characterized in that When the data calibration mechanism is activated, a dynamic self-test gain value is calculated based on the ratio of the calibration data to the actual signal value; The calculated N groups of self-test gain values ​​are compared with the factory gain values ​​respectively, and the N groups of gain errors are calculated. When the N groups of gain errors are all within the set error range, the average of the N groups of self-test gains is determined as the updated self-test gain; when there is at least one group of gain errors exceeding the error range or above, an error processing is performed.

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