阅读说明：本技术 一种磁反馈闭环加速度传感器及其温度补偿方法 (Magnetic feedback closed-loop acceleration sensor and temperature compensation method thereof ) 是由 伍文杰 刘丹丹 涂良成 刘金全 严世涛 于 2020-05-03 设计创作，主要内容包括：本发明公开了一种磁反馈闭环加速度传感器及其温度补偿方法；方法包括：获得磁反馈闭环加速度传感器中磁路的磁感应强度的温度系数；根据温度系数筛选出满足条件的热敏电阻；将热敏电阻与磁反馈执行机构中的压流转换电阻串联,实现磁反馈闭环加速度传感器的磁路的温度系数的补偿。本发明只需检测磁路的磁感应强度的温度系数,省去了复杂耗时的标度因子标定的相关工作,操作简单,省时省力；利用热敏电阻自身温度系数来抵消磁路的温度系数,从而减小磁反馈加速度传感器的标度因子的温度系数方法,可以避免传感器安装所带来的误差以及测试设备自身热胀冷缩所带来的误差所带来的影响,提高了测量精度。(The invention discloses a magnetic feedback closed-loop acceleration sensor and a temperature compensation method thereof; the method comprises the following steps: obtaining the temperature coefficient of the magnetic induction intensity of a magnetic circuit in the magnetic feedback closed-loop acceleration sensor; screening out the thermistors meeting the conditions according to the temperature coefficient; and the thermistor is connected in series with a pressure-current conversion resistor in the magnetic feedback actuating mechanism, so that the compensation of the temperature coefficient of the magnetic circuit of the magnetic feedback closed-loop acceleration sensor is realized. The invention only needs to detect the temperature coefficient of the magnetic induction intensity of the magnetic circuit, saves the related work of calibration of complicated and time-consuming scale factors, and has simple operation, time saving and labor saving; the temperature coefficient of the magnetic circuit is offset by the temperature coefficient of the thermistor, so that the temperature coefficient of the scale factor of the magnetic feedback acceleration sensor is reduced, errors caused by installation of the sensor and the influence caused by errors caused by expansion with heat and contraction with cold of the testing equipment can be avoided, and the measuring precision is improved.)

1. A magnetic feedback closed loop acceleration sensor, comprising: the device comprises a mechanical structure (1), an open loop detection circuit (2), a PID controller (3) and a feedback actuator (4);

the mechanical structure (1) is used for sensing the change of external acceleration and converting the change of the acceleration into electric capacity;

the open loop detection circuit (2) is used for detecting the capacitance and modulating and demodulating the capacitance to obtain a voltage quantity representing acceleration;

the PID controller (3) is used for judging the amount of the inspection mass in the mechanical structure deviating from the balance position according to the voltage amount, and outputting the feedback voltage amount required when the inspection mass in the mechanical structure returns to the balance state through feedback regulation;

the feedback actuator (4) is used for converting the voltage quantity into a current quantity and applying the current quantity to a feedback coil of the mechanical structure, and a balancing force for balancing external acceleration is generated in a magnetic circuit so that the mechanical structure is in a balanced state; it is achieved that the temperature coefficient of the scale factor of the sensor is reduced by a temperature coefficient that counteracts the magnetic induction of the magnetic circuit.

2. A magnetic feedback closed-loop acceleration sensor according to claim 1, characterized by the feedback actuator (4) comprising: the temperature compensation device comprises an operational amplification unit, a voltage-current conversion resistor and a temperature compensation unit;

the operational amplification unit is used for scaling the feedback voltage;

the voltage-current conversion resistor is used for converting the scaled feedback voltage quantity into a current quantity; applying the current quantity to a feedback coil of the mechanical structure to generate a balance force capable of balancing external acceleration;

the temperature compensation unit is used for compensating the temperature effect of the magnetic induction of the magnetic circuit in the sensor.

3. The magnetic feedback closed-loop acceleration sensor of claim 2, characterized in that the temperature compensation unit is a thermistor, connected in series with the voltage-to-current conversion resistor, for compensating the temperature coefficient α of the magnetic induction of the magnetic circuit in the magnetic feedback closed-loop acceleration sensor_BThe temperature effect of (1).

4. A magnetic feedback closed-loop acceleration sensor according to any of the claims 1-3, characterized by, that the mechanical structure (1) comprises a magnetic circuit for generating a constant magnetic field and a sensitive structure placed in the magnetic circuit for sensing external acceleration changes and converting the acceleration changes into capacitance.

5. The magnetic feedback closed loop acceleration sensor of claim 4 characterized in that, the sensitive structure comprises: the vibrator structure and the upper cover bonded with the vibrator structure.

6. The magnetic feedback closed-loop acceleration sensor of claim 5, characterized in that the vibrator structure comprises: the device comprises an outer frame (13), a spring (14), a check mass (15), a movable polar plate (16) arranged on the check mass and a feedback coil (17) arranged on the check mass;

the outer frame (13) is connected to the proof mass (15) via the spring (14); the movable polar plate (16) on the inspection mass and the static polar plate (12) on the upper cover jointly form a polar plate array, the polar plate array is used for converting external acceleration into electric capacity, and the feedback coil (17) on the inspection mass is used for cutting a magnetic induction line in a magnetic circuit and generating a balancing force for balancing the external acceleration.

7. A temperature compensation method of a magnetic feedback closed-loop acceleration sensor is characterized by comprising the following steps:

s1: obtaining magnetic induction of magnetic circuit in magnetic feedback closed-loop acceleration sensorTemperature coefficient α_B；

S2 according to the temperature coefficient α_BScreening out the thermistors R2 which meet the conditions;

s3, the thermistor R2 is connected with a pressure-current conversion resistor R1 in the magnetic feedback actuating mechanism in series to realize the temperature coefficient α of the magnetic circuit of the magnetic feedback closed-loop acceleration sensor_BCompensation of (2).

8. The temperature compensation method of claim 7, wherein in the step of S1, the temperature coefficient of the scale factor of the sensor is characterized by testing the temperature coefficient of the magnetic susceptibility of the magnetic circuit in the sensor.

9. The temperature compensation method of claim 7 or 8, wherein in step S2, according to formula R2 α_R2＝(R1+R2)α_BScreening thermistors R2 which meet the conditions;

wherein R2 is a thermistor of a temperature compensation unit, α_R2Is the temperature coefficient of the thermistor R2, R1 is the voltage-current converting resistor, α_BIs the temperature coefficient of the magnetic circuit of the magnetic feedback closed-loop acceleration sensor.

10. A temperature compensation method according to any one of claims 7-9, characterized in that in step S3 the temperature effect of the sensor is reduced by counteracting the temperature effect of the magnetic induction in the magnetic circuit.

Technical Field

The invention belongs to the technical field of acceleration sensors, and particularly relates to a magnetic feedback closed-loop acceleration sensor and a temperature compensation method thereof.

Background

The acceleration sensor is used for sensing the change of external acceleration and has important application in the fields of inertial navigation and guidance, gravity resource exploration, intelligent manufacturing, automatic driving, consumer electronics and the like. The most common principle of acceleration sensors is based on the newton's second theorem in classical mechanics, and acceleration signals are converted into displacements of proof masses relative to an equilibrium position by a spring-proof mass system, and then the measurement of the acceleration of an object is realized by detecting the displacements. Generally, the acceleration sensor can be divided into an open-loop type and a closed-loop type according to the control mode. Usually, the open-loop accelerometer has the advantages of simple structure and reading circuit, large measuring range and the like, but the bandwidth is easily limited by the structure of the device, and the linearity is poor. In contrast, although the closed-loop accelerometer is complicated in design of circuit structure and control manner, by controlling the sensitive structure of the device in the equilibrium position, the system will obtain a larger range of high linearity, adjustable bandwidth and a larger dynamic range.

Magnetic feedback closed-loop acceleration sensors, which utilize the ampere force generated by a current conducting wire in a magnetic field to provide a feedback force, are one of the most common closed-loop acceleration sensors. The scaling factor of the closed-loop acceleration sensor is determined by the feedback actuator. The temperature of the feedback actuating mechanism can be changed by the change of the external environment temperature or the heating of circuit components in the system. Because the temperature coefficient of the magnetic field intensity of the magnetic circuit of the magnetic feedback closed-loop acceleration sensor is usually larger, the scale factor of the acceleration sensor is easily influenced by temperature disturbance, and the detection accuracy of the magnetic feedback closed-loop acceleration sensor is directly influenced. Optimization of the scale factor temperature coefficient is crucial to high precision acceleration detection.

Disclosure of Invention

Aiming at the defects of the prior art, the invention aims to provide a magnetic feedback closed-loop acceleration sensor, and aims to solve the technical problem of low measurement precision caused by errors caused by the thermal expansion and cold contraction of test equipment and the installation of the magnetic feedback closed-loop acceleration sensor during calibration in the prior art.

The invention provides a magnetic feedback closed loop acceleration sensor, which comprises: the system comprises a mechanical structure, an open loop detection circuit, a PID controller and a feedback actuating mechanism; the mechanical structure is used for sensing the change of external acceleration and converting the change of the acceleration into electric capacity; the open loop detection circuit is used for detecting the capacitance and modulating and demodulating the capacitance to obtain a voltage quantity representing the acceleration; the PID controller is used for judging the amount of the inspection mass in the mechanical structure deviating from the balance position according to the voltage amount, and outputting the feedback voltage amount required when the inspection mass in the mechanical structure returns to the balance state through feedback regulation; the feedback actuator is used for converting the voltage quantity into the current quantity, applying the current quantity to the feedback coil of the mechanical structure and generating a balancing force for balancing the external acceleration in the magnetic circuit so as to enable the mechanical structure to be in a balanced state; it is achieved that the temperature coefficient of the scale factor of the sensor is reduced by a temperature coefficient that counteracts the magnetic induction of the magnetic circuit.

Still further, the feedback actuator comprises: the temperature compensation device comprises an operational amplification unit, a voltage-current conversion resistor and a temperature compensation unit; the operational amplification unit is used for scaling the feedback voltage; the voltage-current conversion resistor is used for converting the scaled feedback voltage quantity into a current quantity; applying the current quantity to a feedback coil of the mechanical structure to generate a balance force capable of balancing external acceleration; the temperature compensation unit is used for compensating the temperature effect of the magnetic induction of the magnetic circuit in the sensor.

Furthermore, the temperature compensation unit is a thermistor connected in series with the voltage-current conversion resistor and used for compensating the temperature coefficient α of the magnetic induction intensity of the magnetic circuit in the magnetic feedback closed-loop acceleration sensor_BThe temperature effect of (1).

Further, the mechanical structure comprises a magnetic circuit for generating a constant magnetic field and a sensitive structure disposed in the magnetic circuit for sensing a change in external acceleration and converting the change in acceleration into a capacitance.

Further, the sensitive structure includes a vibrator structure and a top cover bonded to the vibrator structure.

Furthermore, the oscillator structure can be made of monocrystalline silicon or quartz; the upper cover can be made of monocrystalline silicon, quartz or glass.

Further, the vibrator structure includes: the device comprises a spring, a check mass, a movable polar plate arranged on the check mass and a feedback coil arranged on the check mass; the outer frame is connected with the check mass through a spring; the movable polar plate on the proof mass and the static polar plate on the upper cover jointly form a polar plate array, and the main function is to convert the external acceleration into electric capacity through the array polar plate; the feedback coil on the proof mass is mainly used for cutting the magnetic induction line in the magnetic circuit to generate a balancing force for balancing the external acceleration

In the magnetic feedback closed-loop acceleration sensor provided by the invention, a voltage quantity is converted into a current quantity through a feedback actuating mechanism, the current quantity is applied to a feedback coil of a mechanical structure, and a balancing force for balancing external acceleration is generated in a magnetic circuit to enable the mechanical structure to be in a balanced state; the temperature coefficient of the scale factor of the sensor is reduced by offsetting the temperature coefficient of the magnetic induction of the magnetic circuit; the measurement accuracy is improved.

The invention also provides a temperature compensation method of the magnetic feedback closed-loop acceleration sensor, and aims to solve the technical problem that the temperature coefficient cannot be compensated due to the fact that a specific expression of the temperature coefficient of the scale factor of the magnetic feedback closed-loop acceleration sensor is absent in the prior art.

The invention provides a temperature compensation method of a magnetic feedback closed-loop acceleration sensor, which comprises the following steps:

s1 temperature coefficient α for obtaining magnetic induction of magnetic circuit in magnetic feedback closed loop acceleration sensor_B；

S2 according to the temperature coefficient α_BScreening out the thermistors R2 which meet the conditions;

s3, the thermistor R2 is connected with a pressure-current conversion resistor R1 in the magnetic feedback actuating mechanism in series to realize the temperature coefficient α of the magnetic circuit of the magnetic feedback closed-loop acceleration sensor_BCompensation of (2).

Further, in the step S1, the temperature coefficient α according to the magnetic induction of the magnetic circuit_BIs the main influence factor of the scale factor temperature coefficient of the magnetic feedback closed-loop acceleration sensor, and is expressed by the temperature coefficient of the magnetic induction of a magnetic circuit in the test sensorCharacterizing the temperature coefficient of the scale factor of the sensor.

Further, in step S2, according to the formula R2 α_R2＝(R1+R2)α_BScreening a thermistor R2 satisfying the condition, wherein R2 is the thermistor of a temperature compensation unit α_R2Is the temperature coefficient of the thermistor R2, R1 is the voltage-current converting resistor, α_BIs the temperature coefficient of the magnetic circuit of the magnetic feedback closed-loop acceleration sensor.

Further, in step S3, the temperature effect of the sensor is reduced by canceling the temperature effect of the magnetic induction in the magnetic circuit.

Compared with the prior art, the temperature compensation method provided by the invention has the following advantages:

(1) in the temperature compensation method for the magnetic feedback closed-loop acceleration sensor, a specific expression of a scale factor is obtained through theoretical analysis; and the specific expression of the temperature coefficient of the scale factor is analyzed, and the temperature coefficient of the magnetic induction intensity in the magnetic circuit is far greater than other factors and is the most main factor of the temperature coefficient of the scale factor; the temperature coefficient of the scale factor of the sensor is therefore reduced directly by the temperature coefficient which cancels out the magnetic induction of the magnetic circuit; the invention only needs to detect the temperature coefficient of the magnetic induction intensity of the magnetic circuit, thereby saving the related work of the traditional, complicated and time-consuming scale factor calibration, having simple operation and saving time and labor.

(2) In the temperature compensation method for the magnetic feedback closed-loop acceleration sensor, calibration of scale factors of different types of magnetic feedback closed-loop sensors and test of related temperature coefficients are aimed at; corresponding sensors are required to be installed and fixed in the testing equipment, and errors caused by installation of the sensors and errors caused by expansion with heat and contraction with cold of the testing equipment are random, so that the judgment of related errors cannot be carried out; the temperature coefficient method for counteracting the temperature coefficient of the magnetic circuit by utilizing the temperature coefficient of the thermistor provided by the invention can reduce the temperature coefficient of the scale factor of the magnetic feedback acceleration sensor, avoid the influence caused by the two errors and improve the measurement precision.

Drawings

Fig. 1 is a schematic block diagram of a magnetic feedback closed-loop acceleration sensor provided by an embodiment of the present invention.

Fig. 2 is a schematic structural diagram of a mechanical structure in a magnetic feedback closed-loop acceleration sensor provided by an embodiment of the present invention.

Fig. 3 is a schematic structural diagram of a feedback actuator in a magnetic feedback closed-loop acceleration sensor according to an embodiment of the present invention.

Fig. 4 is a flowchart of an implementation of a temperature compensation method for a magnetic feedback closed-loop acceleration sensor according to an embodiment of the present invention.

In all the drawings, the same reference numerals are used to denote the same elements or structures, where 1 is a sensor mechanical structure, 2 is an open-loop detection circuit, 3 is a PID controller, 4 is a feedback actuator, 11 is an upper cover, 12 is a static pole plate of the upper cover, 13 is an outer frame, 14 is a spring, 15 is a proof mass, 16 is a movable pole plate on the proof mass, 17 is a feedback coil on the proof mass, 18 is a yoke, 19 is a permanent magnet, 10 is a pole piece, a1 and a2 are operational amplifiers, R1 is a voltage-current converting resistor, and R2 is a thermistor.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention more apparent, the present invention is described in further detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.

The invention relates to a technology for compensating the temperature effect of a scale factor of a magnetic feedback closed-loop accelerometer by using the temperature effect of a thermistor, which starts from the main source of the temperature effect of the magnetic feedback closed-loop acceleration sensor and firstly measures the temperature coefficient α of the magnetic induction intensity of a magnetic circuit_BSelecting α satisfying the measured temperature coefficient of magnetic induction density_BTemperature coefficient α of thermistor_R2A thermistor of the relationship (c) is connected in series to the feedback actuator for compensating the temperature effect of the magnetic circuit. The invention avoids the need for complex and time-consuming sensor scale factors, as compared to prior art methodsCalibration work, no extra processing technology and no need of a large number of repeated tests. The method has important application value in large-scale and low-cost compensation occasions of the temperature coefficient of the scale factor.

An embodiment of the present invention provides a magnetic feedback closed-loop MEMS capacitive acceleration sensor, as shown in fig. 1, including: the system comprises a mechanical structure 1, an open loop detection circuit 2, a PID controller 3 and a feedback execution mechanism 4; the mechanical structure 1 is used for sensing the change of external acceleration and further converting the change into electric capacity; the open loop detection circuit 2 is used for detecting the capacitor and modulating and demodulating the capacitor to obtain a corresponding voltage quantity; the PID controller 3 is used for judging the deviation of the inspection mass in the mechanical structure from the balance position according to the demodulated voltage quantity, and further outputting corresponding voltage quantity; the feedback actuator 4 is used for converting the voltage quantity into a current quantity, applying the current to a feedback coil of the mechanical structure, and generating a balance force for balancing external acceleration in a magnetic circuit, wherein the mechanical structure is in a balance state.

Mechanical structure system model as shown in fig. 2, a mechanical structure 1 includes: the device comprises a glass upper cover 11, a static polar plate 12 of the glass upper cover, a silicon outer frame 13, a spring 14, a check mass 15, a movable polar plate 16 on the check mass, a feedback coil 17 on the check mass, a yoke 18, a permanent magnet 19 and a magnetic pole piece 10; the static polar plate 12 of the upper glass cover is positioned on the surface of the upper glass cover 11; the silicon outer frame 13, the spring 14, the inspection mass 15, the movable polar plate 16 on the inspection mass and the feedback coil 17 on the inspection mass form a silicon vibrator structure together; then the glass upper cover 11 and the silicon vibrator structure are bonded together to form a sensitive structure; the yoke 18, the permanent magnet 19 and the magnetic pole piece 10 jointly form a magnetic circuit; the sensitive structure is placed in the magnetic circuit, i.e. a mechanical structure is formed. The magnetic circuit generates a constant magnetic field; the mechanical structure works in a constant magnetic field; the current-carrying feedback coil 11 cuts the magnetic induction lines in the constant magnetic field, causing them to generate the appropriate amperage to pull the proof mass 9 back to the equilibrium position.

As shown in fig. 3, the feedback actuator 4 includes: the operational amplifier A1, the operational amplifier A2, the voltage-current conversion resistor R1 and the thermistor R2 which is connected with the voltage-current conversion resistor R1 in series; operational amplifiers a1 and a2 are used to scale the amount of feedback voltage; the voltage-current conversion resistor R1 is used for converting the feedback voltage quantity after being scaled by the operational amplifier into current quantity; this part is mainly used to generate the current applied to the above-mentioned feedback coil 17. The coil cuts the magnetic induction lines in the magnetic circuit, producing an ampere force that balances the mechanical structure. The thermistor R2 is used for realizing the temperature effect compensation of the scale factor of the magnetic feedback closed-loop acceleration sensor system according to the temperature effect of the thermistor.

The invention provides a scale factor temperature coefficient based on a magnetic feedback closed loop acceleration sensorThe compensation mode of (1); scale factor K of magnetic feedback closed-loop acceleration sensor₁Is mainly determined by the feedback actuator 4; for its scale factor K₁The expression was analyzed and found to be the temperature coefficient α of the magnetic induction of the magnetic circuit in its mechanical structure 1_BThe main role is occupied; temperature coefficient of the final slave scale factorBased on the expression, the temperature coefficient α of a thermistor can be obtained by connecting a thermistor R2 in series through a voltage-current conversion resistor R1_R2Temperature coefficient α for canceling magnetic induction in magnetic circuit_BThereby achieving the scale factor temperature coefficientCompensation of (2).

The invention also provides a temperature compensation method of the magnetic feedback closed-loop acceleration sensor, which specifically comprises the following steps as shown in fig. 4:

step 1, obtaining the temperature coefficient α of the magnetic induction intensity of the magnetic circuit in the magnetic feedback closed loop acceleration sensor_B；

Step 2, according to the temperature coefficient α_BScreening out the thermistors R2 which meet the conditions;

and step 3: the thermistor R2 is connected with a voltage-current conversion resistor R1 in a magnetic feedback actuating mechanism in series to realizeTemperature coefficient α of magnetic circuit of magnetic feedback closed-loop acceleration sensor_BCompensation of (2).

As an embodiment of the present invention, the magnetic circuit device in step 1 includes four permanent magnets, four magnetic pole pieces, and two yokes. The magnetic feedback closed-loop acceleration sensor adopts ampere force generated by cutting a magnetic induction line in a magnetic circuit by an electrified coil as feedback force of a balance sensor, and the feedback force can be expressed as follows:

F＝NBIL＝NBLV/R1＝ma， (1)

where m is the mass of proof mass 15, a is the external acceleration to be detected, N is the number of turns of feedback coil 17, B is the magnetic induction of the magnetic circuit, I is the magnitude of the current in feedback coil 17, L is the length of the feedback coil in the vertical sensitive direction, V is the magnitude of the voltage applied to voltage-to-current converting resistor R1 that can directly reflect the external acceleration, R1 is the voltage-to-current converting resistor, the scale factor K of the magnetic feedback closed-loop acceleration sensor₁The expression of (a) is:

K₁＝mR1/(NBL)， (2)

the formula (2) is used for obtaining the temperature coefficient of the scale factor by differentiating the temperatureThe expression of (a) is:

equation 3 shows that the temperature coefficient of the scale factor of the magnetic feedback closed-loop acceleration sensor consists of three parts: the first is the temperature coefficient of the medium-voltage-current conversion resistor in the feedback actuator 4, which is usually a high-stability resistor, and the temperature coefficient is less than 20 ppm/DEG C; the temperature coefficient of the length of the feedback coil in the vertical sensitive direction on the sensitive mass block is mainly related to an attachment substrate of the coil, and the substrate is generally monocrystalline silicon, and the temperature coefficient of the substrate is about 2.56 ppm/DEG C; and the temperature coefficient of the magnetic induction intensity of the magnetic circuit is mainly related to the temperature coefficient of the permanent magnet material of the magnetic circuit, and the temperature coefficient is about-350 ppm/DEG C by taking samarium cobalt as an example. The temperature coefficient of the magnetic induction of the magnetic circuit dominates the main effect, so equation (3) can be simplified as:

therefore, the temperature coefficient of the magnetic induction intensity of the magnetic circuit can be directly tested, namely the temperature coefficient of the scale factor of the magnetic feedback closed-loop acceleration sensor can be replaced, and the complicated calibration of the temperature coefficient of the scale factor of the sensor is not needed.

As an embodiment of the present invention, in step 2, the temperature effect of the scale factor of the sensor is compensated, and a thermistor R2 is connected in series with the voltage-to-current converting resistor R1, and the compensated scale factor can be expressed as:

K₁＝m(R1+R2)/(NBL)， (5)

temperature coefficient of corresponding compensated scale factorComprises the following steps:

based on the factors described in step 1, equation (6) can be simplified to:

substituting the temperature coefficient of the magnetic induction intensity of the magnetic circuit actually measured in the step 1 and the parameters of the pressure flow resistor into an equation (7) in the step 2; in order to completely cancel the influence of the temperature effect of the magnetic circuit on the magnetic feedback closed-loop acceleration sensor, it can be obtained by making zero on the left side of equation (7), i.e. the temperature coefficient of the scale factor is zero:

R2α_R2＝(R1+R2)α_B(8)

therefore, a thermistor R2 satisfying equation (8) can be selected and applied to an actual magnetic feedback closed-loop acceleration sensor to realize the temperature compensation of the scale factor of the sensor.

To further illustrate the temperature compensation method of the magnetic feedback closed-loop acceleration sensor provided by the embodiment of the present invention, the following is detailed with reference to specific examples:

step 1: fixing a magnetic circuit, a gaussmeter and a thermometer of the magnetic feedback closed-loop MEMS capacitive accelerometer in a temperature box together; the temperature points are totally set to 9 sections, such as 10 ℃, 15 ℃, … and 50 DEG C]Each temperature is stable for 1h, and MAT L AB is used for fitting the magnetic induction intensity of the magnetic circuit and the corresponding temperature to obtain the temperature coefficient α of the magnetic induction intensity of the magnetic circuit_B＝dB/BdT。

Step 2, obtaining the temperature coefficient of the magnetic induction intensity of a magnetic circuit in the magnetic feedback closed-loop MEMS capacitive accelerometer, namely 400 ppm/DEG C, of the step 1, substituting the parameters into an equation (6), namely R2 α, wherein the resistance of a pressure-current conversion resistor of a feedback actuating mechanism 4 of the resistor is 120k omega_R2＝(R1+R2)α_BThe resistance R2 of the thermistor and the temperature coefficient α of the thermistor can be obtained_R2Relation R2 α_R2+48+4×10^-4R1 ═ 0, the resistance that satisfies the relationship can be used to compensate for the temperature coefficient of the accelerometer scale factor; the temperature coefficient of the accelerometer scale factor can be compensated by connecting the resistor meeting the condition with the voltage-current conversion resistor in series.

Compared with the prior art, the temperature coefficient method for counteracting the temperature coefficient of the magnetic circuit by utilizing the temperature coefficient of the thermistor per se, thereby reducing the temperature coefficient of the scale factor of the magnetic feedback acceleration sensor, and avoiding the influence of errors caused by the installation of the sensor and the errors caused by the expansion with heat and contraction with cold of the test equipment per se when the sensor is installed and fixed in the test equipment to test the temperature coefficient of the scale factor; in addition, the temperature coefficient of the magnetic induction intensity of the magnetic circuit is only required to be detected, so that the related work of the traditional, complicated and time-consuming calibration of scale factors is omitted, the operation is simple, the time and the labor are saved, no additional processing technology is required, and a large number of repeated tests are not required.

It will be understood by those skilled in the art that the foregoing is only a preferred embodiment of the present invention, and is not intended to limit the invention, and that any modification, equivalent replacement, or improvement made within the spirit and principle of the present invention should be included in the scope of the present invention.