A zero-adjusting device for a force-balanced accelerometer and a force-balanced accelerometer

Abstract

An embodiment of the present application provides a zero-adjusting device and a force balance accelerometer for a force balance accelerometer, including a zero-adjusting mechanism, which includes a driving unit and a transmission unit. The driving unit is connected to one end of a spring through the transmission unit, and the other end of the spring is connected to a moving electrode plate; a control unit, which is connected to the control end of the driving unit and the control end of a switch used to control the on-off of a feedback circuit; when it is detected that the zero-point voltage of the force balance accelerometer is not within the preset zero-point voltage standard range, the control switch disconnects the feedback circuit, calculates the rough adjustment parameters according to the zero-point voltage, the distance between the moving electrode plate and the fixed electrode plate, the voltage applied to the moving electrode plate, the amplification factor of the feedback circuit, and the ambient temperature, controls the driving unit to act according to the rough adjustment parameters, drives the spring to act through the transmission unit, adjusts the position of the moving electrode plate, and after adjustment, controls the switch to connect the feedback circuit. The present application can reduce the zero-adjusting difficulty and zero-adjusting time, improve the zero-adjusting accuracy, and ensure the measurement accuracy of the instrument.

Description

Technical Field

[0001] The embodiments of the present application relate to the technical field of seismic observation, and particularly to a zero-adjusting device for a force-balanced accelerometer and a force-balanced accelerometer. Background Art

[0002] A force-balanced accelerometer is a high-precision sensor used to sense the acceleration of ground motion and is widely used in strong earthquake observation. Affected by environmental factors such as temperature and air pressure, the force-balanced accelerometer will have zero-point drift. To ensure its normal working state, zero adjustment needs to be carried out regularly. Currently, there are mainly two zero-adjusting methods. One is mechanical zero adjustment. A zero-adjusting port is reserved on the instrument, and the zero-adjusting rotating shaft is manually rotated to achieve zero adjustment. The assembly cost is high, the zero adjustment is difficult and the maintenance cost is high in special installation environments, and the instrument is prone to moisture and malfunction due to inability to be sealed. The other is current zero adjustment. A direct current is generated and acts on the feedback coil to form a reaction force to achieve zero adjustment. Since there is noise in the generated direct current, the accuracy of the accelerometer is affected. Summary of the Invention

[0003] In view of this, the purpose of the embodiments of the present application is to propose a zero-adjusting device for a force-balanced accelerometer and a force-balanced accelerometer to solve the zero-adjusting problem of the force-balanced accelerometer.

[0004] Based on the above purpose, the embodiments of the present application provide a zero-adjusting device for a force-balanced accelerometer, including:

[0005] A zero-adjusting mechanism, including a driving unit and a transmission unit. The driving unit is connected to one end of a spring through the transmission unit, and the other end of the spring is connected to a moving plate.

[0006] A control unit is connected to the control end of the driving unit and the control end of a switch used to control the on-off of the feedback circuit. When it is detected that the zero-point voltage of the force-balanced accelerometer is not within the preset zero-point voltage standard range, the control unit controls the switch to disconnect the feedback circuit, calculates the coarse adjustment parameters according to the zero-point voltage, the distance between the moving plate and the fixed plate, the voltage applied to the moving plate, the amplification factor of the feedback circuit, and the environmental temperature, controls the driving unit to act according to the coarse adjustment parameters, drives the spring to act through the transmission unit, adjusts the position of the moving plate, and then controls the switch to connect the feedback circuit after the adjustment.

[0007] Optionally, the driving unit includes a stepping motor and a reducer; calculating the coarse adjustment parameters according to the zero-point voltage, the distance between the moving plate and the fixed plate, the voltage applied to the moving plate, the amplification factor of the feedback circuit, and the environmental temperature, the method is:

[0008]

[0009] Wherein, is the coarse adjustment angle, U O is the zero-point voltage, D is the distance between the moving plate and the fixed plate, U M is the peak-to-peak value of the sine wave voltage applied to the moving plate, G is the amplification factor of the feedback circuit, d is the stroke of the moving plate when the stepping motor rotates one degree, T is the ambient temperature, and β is the influence coefficient of temperature on the plate.

[0010] Optionally, after adjusting the position of the moving plate according to the coarse adjustment parameter, when the control unit detects that the zero-point voltage of the force balance accelerometer is not within the zero-point voltage standard range, it determines the fine adjustment parameter according to the voltage amount adjusted by the stepping motor rotating one degree and the preset number of rotations, and controls the driving unit to act according to the fine adjustment parameter.

[0011] Optionally, the method for determining the fine adjustment parameter according to the voltage amount adjusted by the stepping motor rotating one degree and the preset number of rotations is as follows:

[0012]

[0013] wherein, is the fine adjustment angle, U i is the zero-point voltage detected after the i-th rotation of the stepping motor, U i-1 is the zero-point voltage detected after the (i - 1)-th rotation of the stepping motor, U n is the zero-point voltage detected after the n-th rotation of the stepping motor.

[0014] Optionally, the preset number of rotations is determined according to the zero adjustment time and the zero adjustment accuracy.

[0015] Optionally, after adjusting the position of the moving plate according to the fine adjustment parameter, when the control unit detects that the zero-point voltage of the force balance accelerometer is not within the zero-point voltage standard range, it repeats the process of determining the fine adjustment parameter to finely adjust the position of the moving plate until the detected zero-point voltage is within the zero-point voltage standard range.

[0016] Optionally, when receiving the zero adjustment instruction, the control unit detects the zero-point voltage of the force balance accelerometer.

[0017] Optionally, the transmission unit includes a turbine and a worm. One end of the worm is connected to one end of the spring. The stepping motor and the reducer act, and the spring is driven to expand and contract through the turbine and the worm to adjust the position of the moving plate.

[0018] The embodiment of the present application further provides a force balance accelerometer, including the zero adjustment device as described above.

[0019] As can be seen from the above, the zero-adjusting device and the force balance accelerometer provided by the embodiments of the present application adopt a zero-adjusting mechanism with a stepping motor, a speed reducer, and a worm and worm gear structure, which can reduce the zero-adjusting torque, the difficulty and cost of zero adjustment. According to the installation environment of the instrument, remote zero adjustment can be realized to reduce the maintenance difficulty and zero-adjusting time. During zero adjustment, a non-feedback method of rough adjustment first and then fine adjustment is adopted, which can achieve precise zero adjustment in a harsh environment, improve the adaptability of the instrument, and ensure the measurement accuracy of the instrument. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the following will briefly introduce the drawings required for the description of the embodiments or the prior art. Obviously, the drawings in the following description are only the embodiments of the present application. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0021] Figure 1 Schematic diagram of the principle of the force balance accelerometer for some embodiments;

[0022] Figure 2 Schematic diagram of the principle of mechanical zero adjustment for some embodiments;

[0023] Figure 3 Block diagram of the structure of the zero-adjusting device according to the embodiment of the present application;

[0024] Figure 4 Schematic diagram of the structure of the zero-adjusting mechanism according to the embodiment of the present application;

[0025] Figure 5 Schematic diagram of the flow of the zero-adjusting method according to the embodiment of the present application;

[0026] Figure 6 Schematic diagram of a partial structure of the force balance accelerometer according to the embodiment of the present application;

[0027] Figure 7 Schematic diagram of a partial structure of the force balance accelerometer according to another embodiment of the present application. DETAILED DESCRIPTION OF THE EMBODIMENTS

[0028] To make the objectives, technical solutions, and advantages of the present disclosure clearer, the following further describes the present disclosure in detail with reference to specific embodiments and the accompanying drawings.

[0029] It should be noted that, unless otherwise defined, the technical terms or scientific terms used in the embodiments of this application should have the ordinary meanings understood by those of ordinary skill in the art to which this disclosure belongs. The "first", "second" and similar terms used in the embodiments of this application do not indicate any order, quantity or importance, but are only used to distinguish different components. Words such as "including" or "comprising" mean that the elements or objects appearing before this word cover the elements or objects listed after this word and their equivalents, without excluding other elements or objects. Words such as "connected" or "coupled" are not limited to physical or mechanical connections, but may include electrical connections, whether direct or indirect. "Upper", "lower", "left", "right", etc. are only used to indicate relative positional relationships, and when the absolute position of the object being described changes, the relative positional relationship may also change accordingly.

[0030] As Figure 1 shown, in the related art, a force balance accelerometer includes a mass block, capacitor plates, a demodulation circuit, a feedback circuit, a proportional derivative circuit, etc. The capacitor plates include a movable plate and a fixed plate. The movable plate includes an upper plate and a lower plate. The fixed plate is located between the upper plate and the lower plate. The mass block is connected to the upper and lower plates by springs. A sine wave voltage with the same amplitude and opposite directions is applied to the upper and lower plates. When the fixed plate is at the middle position between the upper and lower plates, the output voltage is 0. When the ground vibrates, the position of the mass block changes, driving the upper and lower plates to move relative to each other through the springs. The voltage output by the fixed plate is amplified and demodulated by the demodulation circuit and then an output voltage proportional to the acceleration is output; on the one hand, the output voltage generates a feedback force opposite to the vibration direction of the movable plate through the feedback coil to hinder the vibration of the movable plate, and on the other hand, it is output after passing through a proportional derivative circuit composed of a proportional resistor and a differential capacitor. Among them, the transfer function of the force balance accelerometer can be expressed as:

[0031]

[0032] Among them, Gd is the electromechanical constant, which is determined by the sine wave voltage, the plate spacing, and the amplification factor of the amplifier; D is the mechanical pendulum damping, ω m is the natural vibration angular frequency of the mechanical pendulum, E is the electromagnetic constant, C is the differential capacitor, M is the mass of the mechanical pendulum, and R is the proportional resistor.

[0033] Before the force balance accelerometer works for the first time, zero adjustment is required to ensure a normal working state. During use, affected by environmental factors such as temperature and air pressure, the force balance accelerometer will exhibit a zero drift phenomenon, and it is difficult for its fixed plate to always be in the middle position between the upper and lower plates, that is, it is difficult to always be in the zero position state. Therefore, it is necessary to perform zero adjustment on it regularly to ensure the measurement accuracy of the instrument.

[0034] As Figure 2 shown, mechanical zero adjustment uses the lever principle to adjust the zero point. The first rigid body 20 is connected to the moving plate through a spring 25, the second rigid body 21 is connected to the fixed plate, and the first rigid body 20 and the second rigid body 21 are connected through an adjusting rod 22 and an elastic telescopic piece 23. By rotating the adjusting screw 24, the length of the elastic telescopic piece 23 can be changed. The slender adjusting rod 22 can deform with the deformation of the elastic telescopic piece 23, thereby changing the relative height of the first rigid body and the second rigid body, achieving the purpose of adjusting the positions of the upper and lower plates and realizing zero adjustment. In order to reduce the influence of the deformation of the material itself and factors such as temperature and air pressure, the hardness of the adjusting rod is very high, and the zero adjustment torque needs to reach more than 8 times the full scale of the accelerometer measurement, that is, more than 16G to achieve zero adjustment, which is difficult.

[0035] Current zero adjustment requires generating a DC voltage through a digital-to-analog converter, obtaining the required DC current through resistor voltage division and acting on the feedback coil to form a reaction force on the plate to achieve zero adjustment. Even with a high-precision digital-to-analog converter, the generated DC voltage still has noise, and the noise acting on the coil greatly increases the noise of the accelerometer and reduces the measurement accuracy of the instrument.

[0036] In view of this, the present application provides a zero adjustment device for a force balance accelerometer, including a zero adjustment mechanism and a control unit. The zero adjustment mechanism adopts a stepping motor, a reducer and a worm and worm gear structure, which can reduce the adjustment torque and the difficulty of zero adjustment. The control unit controls the zero adjustment mechanism to perform rough adjustment and fine adjustment on the plate position in sequence, so as to accurately adjust it to the zero position, without introducing additional noise, and can ensure the measurement accuracy of the force balance accelerometer.

[0037] Hereinafter, the technical solution of the present application will be further described in detail through specific embodiments.

[0038] As Figure 3 、 4 shown, the present application provides a zero adjustment device for a force balance accelerometer, including:

[0039] A zero adjustment mechanism, including a driving unit and a transmission unit. The driving unit is connected to one end of the spring through the transmission unit, and the other end of the spring is connected to the moving plate;

[0040] A control unit, connected to the control end of the driving unit and the control end of a switch for controlling the on / off of the feedback circuit; when it is detected that the zero voltage of the force balance accelerometer is not within the preset zero voltage standard range, the control switch disconnects the feedback circuit, calculates the rough adjustment parameters according to the zero voltage, the distance between the moving plate and the fixed plate, the voltage applied to the moving plate, the amplification factor of the feedback circuit and the ambient temperature, controls the driving unit to act according to the rough adjustment parameters, drives the spring to act through the transmission unit, adjusts the position of the moving plate, and after adjustment, controls the switch to connect the feedback circuit.

[0041] The zero adjustment device provided in this embodiment includes a control unit and a zero adjustment mechanism installed on a force balance accelerometer. The zero adjustment mechanism includes a driving unit and a transmission unit. The rigid body 36 of the force balance accelerometer is fixedly connected to the driving unit. The driving end of the driving unit is connected to one end of a spring 34 through the transmission unit, and the other end of the spring 34 is connected to a moving electrode plate 35. The control signal output end of the control unit is connected to the control end of the driving unit. The control unit can control the driving unit to act, drive the spring to act through the transmission unit, and then drive the moving electrode plate to act, so as to achieve the zero adjustment purpose by adjusting the position of the moving electrode plate.

[0042] In some embodiments, in order to achieve the miniaturized design of the force balance accelerometer and at the same time achieve an accurate zero adjustment function, a zero adjustment structure combination of a small stepping motor, a reducer, and a worm and worm gear is selected. The driving unit includes a stepping motor 30 and a reducer 31, and the transmission unit includes a worm wheel 32 and a worm 33. Using the driving unit and the transmission unit of this structure can effectively reduce the torque, reduce the difficulty of zero adjustment, and also reduce the cost.

[0043] Since the zero adjustment torque is reduced and the force balance accelerometer is a deep negative feedback system, under the action of the feedback force, the spring 34 will rotate with the worm 33, resulting in the rotation stroke of the moving electrode plate 35 not being equal to the rotation stroke of the worm 33, which affects the zero adjustment accuracy. To solve this problem, this embodiment adopts a non-feedback zero adjustment method. During zero adjustment, the control unit controls the switch on the feedback circuit path to be disconnected to cut off the feedback circuit, so that the spring is in a free expansion and contraction state during zero adjustment, ensuring that the stroke of the moving electrode plate is equal to the rotation stroke of the worm, and then accurately adjusting the position of the moving electrode plate by driving the worm to act. After zero adjustment, the control unit controls the switch to connect the feedback circuit to ensure the normal function of the accelerometer.

[0044] In some embodiments, according to relevant regulations, the standard range of the zero-point voltage should be less than 10 mV, that is, the zero-point voltage needs to be adjusted within the standard range of the zero-point voltage. To achieve accurate zero adjustment, this embodiment adopts a method of coarse adjustment first and then fine adjustment. That is, during zero adjustment, coarse adjustment is carried out first. If the zero-point voltage is still not within the standard range of the zero-point voltage after coarse adjustment, fine adjustment is continued, and the zero-point voltage is adjusted within the standard range of the zero-point voltage after one or several fine adjustments.

[0045] Specifically, during coarse tuning, the control unit uses the voltage acquisition circuit to collect the zero-point voltage output by the accelerometer. If the zero-point voltage is not within the standard range of the zero-point voltage, the control switch disconnects the feedback circuit. According to the zero-point voltage, the distance between the moving plate and the fixed plate, the voltage applied to the moving plate, the amplification factor of the feedback circuit, and the ambient temperature, the coarse tuning parameters are calculated. The driving unit is controlled to act according to the coarse tuning parameters, and the spring is driven to act through the transmission unit to adjust the position of the moving plate. After adjustment, the control switch connects the feedback circuit. That is, during coarse tuning, the feedback circuit is first disconnected to ensure that the spring is in a free expansion and contraction state during the zero adjustment process. Then, according to the calculated coarse tuning parameters, the driving unit is controlled to act, driving the transmission unit to act, and the position of the moving plate is adjusted. After coarse tuning, the feedback circuit is connected.

[0046] In some ways, according to the zero-point voltage, the distance between the moving plate and the fixed plate, the voltage applied to the moving plate, the amplification factor of the feedback circuit, and the ambient temperature, the coarse tuning parameters are calculated. The method is as follows:

[0047]

[0048] Among them, is the coarse tuning angle, U O is the zero-point voltage, D is the distance between the moving plate and the fixed plate, and the value can be 0.3 mm. U M is the peak-to-peak value of the sine wave voltage applied to the moving plate, G is the amplification factor of the feedback circuit, d is the stroke of the moving plate when the stepping motor rotates one degree, T is the ambient temperature, and β is the influence coefficient of temperature on the plate.

[0049] In some embodiments, the control unit is further configured to, after adjusting the position of the moving plate according to the coarse tuning parameters, when it is detected that the zero-point voltage of the force balance accelerometer is not within the standard range of the zero-point voltage, determine the fine tuning parameters according to the voltage amount adjusted by the stepping motor when it rotates one degree and the preset number of rotations, and control the driving unit to act according to the fine tuning parameters.

[0050] In this embodiment, after coarse tuning, the control unit uses the voltage acquisition circuit to collect the zero-point voltage output by the accelerometer. If the zero-point voltage is still not within the standard range of the zero-point voltage, the control switch disconnects the feedback circuit. According to the voltage amount adjusted by the stepping motor when it rotates one degree and the preset number of rotations, the fine tuning parameters are determined. The driving unit is controlled to act according to the fine tuning parameters, and the position of the moving plate is continuously adjusted through the transmission of the transmission unit. After adjustment, the control switch connects the feedback circuit.

[0051] In some ways, according to the voltage amount adjusted by the stepping motor when it rotates one degree and the preset number of rotations, the fine tuning parameters are determined. The method is as follows:

[0052]

[0053] Among them, For fine - tuning the angle, U i is the zero - point voltage detected after the i - th rotation of the stepper motor, U i-1 is the zero - point voltage detected after the (i - 1)-th rotation of the stepper motor, U n is the zero - point voltage detected after the n - th rotation of the stepper motor. n is the number of rotations, which can be determined according to the zero - adjustment time and zero - adjustment accuracy. The more the number of rotations, the higher the zero - adjustment accuracy, and the longer the required zero - adjustment time. Conversely, the fewer the number of rotations, the lower the zero - adjustment accuracy, and the shorter the required zero - adjustment time. In practical applications, an appropriate number of rotations can be selected by balancing the zero - adjustment time and zero - adjustment accuracy.

[0054] The fine - tuning method is to control the stepper motor to rotate in a short - distance and small - stroke manner for a predetermined number of rotations. After each rotation, the corresponding zero - point voltage is obtained. The change value of the zero - point voltage per degree of rotation of the stepper motor is calculated by summing and averaging, and then the fine - tuning angle is obtained. Optionally, the stepper motor is controlled to rotate one degree every 500 ms. Considering the zero - adjustment time and accuracy comprehensively, the number of rotations can be set to 30 times, and 30 zero - point voltages can be obtained. According to the 30 zero - point voltage values, the fine - tuning angle is calculated according to formula 3, and the zero - adjustment time required to adjust to the zero - position state is less than 30 seconds.

[0055] In some embodiments, after the control unit adjusts the position of the moving plate according to the fine - tuning parameters, when the zero - point voltage of the force - balance accelerometer detected is not within the zero - point voltage standard range, the process of repeatedly determining the fine - tuning parameters to finely adjust the position of the moving plate is performed until the detected zero - point voltage is within the zero - point voltage standard range.

[0056] In this embodiment, after the first fine - tuning, the control unit uses the voltage acquisition circuit to collect the zero - point voltage output by the accelerometer. If the zero - point voltage is still not within the zero - point voltage standard range, the control switch disconnects the feedback circuit, determines the fine - tuning parameters, controls the driving unit to act according to the fine - tuning parameters, and continues to adjust the position of the moving plate through the transmission of the transmission unit. After the adjustment, the control switch connects the feedback circuit. That is, if the first fine - tuning does not achieve the zero - adjustment purpose, the fine - tuning process can be repeated multiple times until the zero - position state is adjusted.

[0057] Among them, the first rough - tuning realizes rapid zero - adjustment without considering external interference. If the accelerometer is in a stable environment, zero - adjustment can generally be completed. If it is in an interference environment such as rain, strong wind, strong magnetic field, or a vehicle passing by nearby, these interference factors will be transmitted to the accelerometer through the ground, causing small movements of the accelerometer. At this time, a second fine - tuning is required, and even multiple fine - tunings may be required until the zero - position state is reached (generally, the zero - position state can be reached after one fine - tuning).

[0058] Such as Figure 5As shown in the figure, the process of zero adjustment using the zero adjustment device of the present application includes: The control unit receives a zero adjustment instruction, uses the voltage acquisition circuit to collect the zero voltage output by the accelerometer, and determines whether the zero voltage is within the zero voltage standard range. If it is, the zero adjustment ends; if not, the feedback circuit is disconnected, the coarse adjustment parameter is calculated, the driving unit is controlled to act according to the coarse adjustment parameter, and the moving plate is driven by the transmission unit to adjust towards the zero position. After the adjustment, the feedback circuit is connected. After the coarse adjustment, the voltage acquisition circuit is used to collect the zero voltage output by the accelerometer, and it is determined whether the zero voltage is within the zero voltage standard range. If it is, the zero adjustment ends; if not, the feedback circuit is disconnected, the fine adjustment parameter is calculated, the driving unit is controlled to act according to the fine adjustment parameter, and the moving plate is driven by the transmission unit to adjust towards the zero position. After the adjustment, the feedback circuit is connected. After the first fine adjustment, the zero voltage output by the accelerometer is collected, and it is determined whether the zero voltage is within the zero voltage standard range. If not, the feedback circuit is disconnected, the fine adjustment parameter is calculated, the driving unit is controlled to act according to the fine adjustment parameter, and the moving plate is driven by the transmission unit to adjust towards the zero position. After the adjustment, the feedback circuit is connected. The fine adjustment process is repeated multiple times until the zero voltage is within the zero voltage standard range, and the zero adjustment ends.

[0059] In some embodiments, when zero adjustment is required, the seismic data collector is used to send a zero adjustment instruction to the control unit. According to the application scenario of the instrument, the zero adjustment instruction can be sent wirelessly (for example, sending the zero adjustment instruction for a certain period of time), or sent through the serial port. Achieving zero adjustment remotely reduces the difficulty of zero adjustment and improves maintainability. The voltage acquisition circuit can use a high-precision resistor voltage division network and a high-precision analog-to-digital converter to collect the zero voltage of the accelerometer. In some cases, the output voltage range of the accelerometer is ±5V. The output voltage is stepped down to within the reference voltage range of a 24-bit high-precision analog-to-digital converter (such as 0 - 2.5V) through a high-precision, low-temperature drift resistor voltage division network. After the 24-bit high-precision analog-to-digital converter collects the voltage value, it sends it to the control unit. The control unit performs median filtering on the voltage values received multiple times to obtain the zero voltage.

[0060] The zero adjustment device of the force balance accelerometer provided by the embodiments of the present application adopts a zero adjustment mechanism with a stepper motor, a reducer, and a worm and worm gear structure, which can reduce the zero adjustment torque, the difficulty and cost of zero adjustment; according to the installation environment of the instrument, remote zero adjustment can be achieved to reduce the maintenance difficulty; during zero adjustment, a non-feedback type of coarse adjustment first and then fine adjustment method is adopted, which can achieve precise zero adjustment in a harsh environment, improve the adaptability of the instrument, and ensure the measurement accuracy of the instrument.

[0061] Such as Figure 6 、 7As shown, in some embodiments, the force balance accelerometer includes a base 4. A plurality of hexagon socket head cap screws 1 are installed on the base 4 for horizontal adjustment, and a horizontal bubble 10 is installed on the top plate for observing the horizontal state of the instrument. The base 4 is connected to the top plate through a tripod 11 arranged at 120 degrees. Three mechanical pendulums arranged at 120 degrees are installed on the base 4. Each mechanical pendulum is configured with a corresponding zero adjustment device. The rigid body of the mechanical pendulum is fixedly connected to a stepper motor 14, a speed reducer 13, a turbine 5, and a worm 6. The worm 6 is connected to a plate 15 through a spring 3. The output end of the fixed plate of the mechanical pendulum is connected to a feedback circuit, which is implemented based on a control circuit board 2. After the feedback circuit amplifies and demodulates the output voltage of the mechanical pendulum, it is input into a feedback coil 12 through the output end of an operational amplifier to form a feedback force. At the same time, the voltage output from the output end of the operational amplifier forms an output signal after passing through a proportional derivative circuit and is uploaded to a host computer through a aviation plug 9. A control unit 7 is used to implement functions such as zero voltage detection and zero adjustment, and a control circuit 8 is used to implement functions such as power conversion, serial communication, and uploading the collected vibration signals to the host computer through the aviation plug 9.

[0062] In some embodiments, to reduce costs and meet the requirements of miniaturized applications, the size of the stepper motor is 39mm×29mm, and a small stepper motor with a torque of 0.24N and a step angle of 0.9 degrees is selected. The size of the speed reducer is 40mm×50mm, and the reduction ratio is 1:100. The power supply circuit of the force balance accelerometer can provide power supply voltages of ±12V, ±6V, 3.3V, and 2.5V for each module to work normally.

[0063] Those of ordinary skill in the art should understand that: the discussion of any of the above embodiments is only exemplary, and is not intended to imply that the scope of the present disclosure (including the claims) is limited to these examples; under the concept of the present disclosure, the technical features in the above embodiments or different embodiments can also be combined, the steps can be implemented in any order, and there are many other variations in different aspects of the embodiments of the present application as described above, which are not provided in detail for the sake of brevity.

[0064] In addition, for simplicity of explanation and discussion, and in order not to make the embodiments of the present application difficult to understand, well-known power / ground connections to integrated circuit (IC) chips and other components may or may not be shown in the provided drawings. Further, the devices may be shown in block diagram form in order to avoid making the embodiments of the present application difficult to understand, and this also takes into account the fact that details of the implementation of these block diagram devices are highly dependent on the platform on which the embodiments of the present application are to be implemented (i.e., these details should be fully within the understanding of those skilled in the art). In cases where specific details (e.g., circuits) are set forth to describe exemplary embodiments of the present disclosure, it will be apparent to those skilled in the art that the embodiments of the present application may be practiced without these specific details or with variations of these specific details. Accordingly, these descriptions should be considered illustrative rather than restrictive.

[0065] Although the present disclosure has been described in connection with specific embodiments thereof, many alternatives, modifications, and variations of these embodiments will be apparent to those of ordinary skill in the art based on the foregoing description. For example, other memory architectures (e.g., dynamic RAM (DRAM)) may be used with the embodiments discussed.

[0066] Embodiments of the present application are intended to cover all such alternatives, modifications, and variations that fall within the broad scope of the appended claims. Therefore, any omissions, modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of the embodiments of the present application shall be included within the protection scope of the present disclosure.

Claims

1. A zero-adjusting device for a force-balanced accelerometer, characterized in that, Comprising: A zero-adjusting mechanism, including a driving unit and a transmission unit, wherein the driving unit is connected to one end of a spring through the transmission unit, and the other end of the spring is connected to a movable electrode plate; A control unit, connected to the control end of the driving unit and the control end of a switch for controlling the on / off of a feedback circuit; when it is detected that the zero-point voltage of the force balance accelerometer is not within the preset zero-point voltage standard range, the control unit controls the switch to disconnect the feedback circuit, calculates a coarse adjustment parameter according to the zero-point voltage, the distance between the movable electrode plate and the fixed electrode plate, the voltage applied to the movable electrode plate, the amplification factor of the feedback circuit, and the ambient temperature, controls the driving unit to act according to the coarse adjustment parameter, drives the spring to act through the transmission unit, adjusts the position of the movable electrode plate, and after adjustment, controls the switch to connect the feedback circuit.

2. The zero-adjusting device of the force balance accelerometer according to claim 1, characterized in that, The driving unit includes a stepping motor and a speed reducer; calculating a coarse adjustment parameter according to the zero-point voltage, the distance between the movable electrode plate and the fixed electrode plate, the voltage applied to the movable electrode plate, the amplification factor of the feedback circuit, and the ambient temperature, the method is: Among them, is the coarse adjustment angle, U O is the zero-point voltage, D is the distance between the moving plate and the fixed plate, U M is the peak-to-peak value of the sine wave voltage applied to the moving plate, G is the amplification factor of the feedback circuit, d is the stroke of the moving plate when the stepping motor rotates one degree, T is the ambient temperature, and β is the temperature influence coefficient on the plate.

3. The zero-adjusting device of the force balance accelerometer according to claim 2, characterized in that After the control unit adjusts the position of the movable electrode plate according to the coarse adjustment parameter, when it is detected that the zero-point voltage of the force balance accelerometer is not within the zero-point voltage standard range, the control unit determines a fine adjustment parameter according to the voltage amount adjusted by the stepping motor rotating one degree and the preset number of rotations, and controls the driving unit to act according to the fine adjustment parameter.

4. The zero-adjusting device of the force balance accelerometer according to claim 3, characterized in that, The method for determining the fine adjustment parameter according to the voltage amount adjusted by the stepping motor rotating one degree and the preset number of rotations is: Among them, is the fine-tuning angle, U i is the zero-point voltage detected after the i-th rotation of the stepper motor, U i-1 is the zero-point voltage detected after the (i - 1)-th rotation of the stepper motor, U n is the zero-point voltage detected after the n-th rotation of the stepper motor.

5. The zeroing device of the force balance accelerometer according to claim 3 or 4, characterized in that, The preset number of rotations is determined according to the zero-adjusting time and the zero-adjusting accuracy.

6. The zero-adjusting device of the force balance accelerometer according to claim 3 or 4, characterized in that After the control unit adjusts the position of the movable electrode plate according to the fine adjustment parameter, when it is detected that the zero-point voltage of the force balance accelerometer is not within the zero-point voltage standard range, the control unit repeats the process of determining the fine adjustment parameter to finely adjust the position of the movable electrode plate until the detected zero-point voltage is within the zero-point voltage standard range.

7. The zero-adjusting device of the force balance accelerometer according to claim 1, characterized in that The control unit is used to detect the zero-point voltage of the force balance accelerometer when receiving a zero-adjusting instruction.

8. The zero-adjusting device of the force balance accelerometer according to claim 2, characterized in that, The transmission unit includes a turbine and a worm, one end of the worm is connected to one end of the spring, the stepping motor and the speed reducer act, and drive the spring to expand and contract through the turbine and the worm to adjust the position of the movable electrode plate.

9. A force balance accelerometer, characterized in that, Comprising the zero-adjusting device of the force balance accelerometer according to any one of claims 1-8.

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