CN111811385B - Double-axis capacitance displacement detection device and method based on double modulation method - Google Patents

Abstract

Translated fromChinese

本发明属于位移测量领域，公开了一种基于双调制法的双轴电容位移检测装置和方法。包括定极板；动极板；第一驱动电压模块，产生用于调制水平位移变化的正负驱动载波，加载于定极板上；第二驱动电压模块，产生用于调制间距变化方向的单路驱动载波，加载于定极板上，以频分复用方式与第一驱动电压模块一起工作；电荷放大器，与动极板相连，用于将水平位移及间距变化引起的差分电容信号转化为电压；第一同步解调模块和第二同步解调模块，用于对电压信号进行解调，分别得到含有水平位移变化和间距变化的直流信号。本发明同时实现了水平和竖直方向电容位移检测，相对于单轴电容位移检测，可检测非敏感轴方向的电容变化量，提高电容位移检测精度。

The invention belongs to the field of displacement measurement, and discloses a dual-axis capacitance displacement detection device and method based on a dual modulation method. It includes a fixed pole plate; a moving pole plate; a first driving voltage module, which generates positive and negative driving carrier waves for modulating horizontal displacement changes, and loads them on the fixed pole plate; a second driving voltage module, which generates a single driving voltage module for modulating the direction of spacing change. It is loaded on the fixed pole plate and works together with the first driving voltage module in a frequency division multiplexing manner; the charge amplifier is connected to the moving pole plate, and is used to convert the differential capacitance signal caused by the horizontal displacement and spacing change into voltage; the first synchronous demodulation module and the second synchronous demodulation module are used to demodulate the voltage signal to obtain the DC signal containing the horizontal displacement change and the spacing change respectively. The invention simultaneously realizes the detection of capacitance displacement in the horizontal and vertical directions. Compared with the single-axis capacitance displacement detection, the capacitance variation in the non-sensitive axis direction can be detected, and the detection accuracy of capacitance displacement can be improved.

Description

Double-axis capacitance displacement detection device and method based on double modulation method

Technical Field

The invention belongs to the field of displacement measurement, and particularly relates to a double-axis capacitance displacement detection device and method based on a double modulation method.

Background

Capacitance displacement detection is a common mode of displacement measurement, and the variation of the relative position of two objects can be obtained by detecting the capacitance variation between the two objects. Since the variation of the capacitance is detected, the capacitance formula is used

It can be seen that the amount of change in capacitance C caused by the dielectric constant ε of the medium between the two measuring objects, the facing area A between the two measuring objects and the two measurementsMeasuring the spacing d between the objects. In general, the detection device is placed in a fixed environment, and therefore the dielectric constant ∈ is a certain value and is not to be measured. Therefore, the position relationship between the two objects can be reflected by detecting the capacitance change caused by the change of the relative area A and the change of the relative distance d of the two objects, namely the area-variable capacitance displacement detection and the distance-variable capacitance displacement detection.

For the area-variable capacitance displacement detection mode, displacement is mainly detected by detecting the size of differential capacitance caused by the change of the dead areas of the two capacitance plates, the capacitance plates can be made very small so as to increase the number, the more the capacitance plates are arranged, the larger the signal of the differential capacitance is, the signal detection is facilitated, and therefore, the area-variable capacitance displacement detection mode is mainly used in a micro-mechanical structure; for the variable-pitch capacitance displacement detection mode, the capacitance change caused by the change of the pitch of the capacitance plates is mainly detected, the pitch cannot be overlarge, otherwise, the nonlinear influence is introduced, the measurement error is caused, and therefore high-precision assembly is needed.

The area-variable capacitance displacement detection mainly detects the capacitance variation caused by the change of the opposite area between the movable and fixed polar plates. As shown in fig. 1, when the displacement or acceleration in the detection direction causes a relative displacement Δ x between the movable plate and the fixed plate, the area of the capacitor opposite to the movable plate and the fixed plate is changed. The expression of the two capacitances generated by the area change in this process can be expressed as

And

the magnitude of the differential capacitance at this time can be expressed as:

wherein epsilon is the dielectric constant of the medium between the polar plates, a is the width of the movable polar plate and the fixed polar plate, and b is the distance between the two fixed polar plates. The voltage output expression after passing through the charge amplifier is as follows:

and a reference signal V_P1sin(ω₁t) the voltage signal obtained after synchronous demodulation is:

the variable-pitch capacitance displacement detection mainly detects capacitance variation caused by the change of the pitch of the movable and fixed polar plates. As shown in fig. 2, when the distance between the movable plate and the fixed plate changes by Δ d, the capacitance between the fixed plate and the fixed plate is changed, and the capacitance change expression at this time is:

when Δ d < d,

wherein epsilon is the dielectric constant of the medium between the polar plates, l is the length of the part of the positive area of the movable and fixed polar plates, w is the width of the part of the positive area of the movable and fixed polar plates, and d is the distance between the movable and fixed polar plates. The voltage after conversion by the charge amplifier is expressed as:

and a reference signal V_P2 sin(ω₂t) the voltage signal obtained after synchronous demodulation is:

from the voltage output formula V_o1And V_o2It can be seen that both the displacement variation Δ x in the horizontal direction and the pitch variation Δ d in the vertical direction are converted into voltage variations, but both detection methods can only detect one of the variables, i.e., a single-direction variable.

Disclosure of Invention

The invention aims to provide a double-axis capacitance displacement detection device and method based on a double modulation method, aiming at solving the problem that the existing capacitance displacement detection device can only obtain single direction variable information.

In order to achieve the above object, an aspect of the present invention provides a dual-axis capacitance displacement detection apparatus based on a dual modulation method, including: the device comprises a fixed polar plate, a movable polar plate, a first driving voltage module, a second driving voltage module, a charge amplifier, a first synchronous demodulation module and a second synchronous demodulation module;

the first driving voltage module generates positive and negative driving carriers for modulating displacement change in the horizontal direction and loads the positive and negative driving carriers on the fixed polar plate;

the second driving voltage module generates a single-path driving carrier wave for modulating the change direction of the spacing, is also loaded on the fixed polar plate and works together with the first driving voltage module in a frequency division multiplexing mode;

the charge amplifier is connected with the movable polar plate and used for converting differential capacitance signals caused by horizontal displacement and distance change into voltage signals;

the first synchronous demodulation module and the second synchronous demodulation module are used for synchronously demodulating the voltage signals obtained by conversion to respectively obtain direct current signals containing horizontal direction displacement variation and space variation.

Furthermore, the movable polar plate and the fixed polar plate are arranged in a facing manner to form a differential capacitor.

Further, the fixed polar plate comprises a positive fixed polar plate and a negative fixed polar plate; the positive fixed polar plates and the negative fixed polar plates are arranged in a parallel and staggered equal-interval array form.

Further, the positive and negative driving carrier generated by the first driving voltage module is ± V_p1sin(ω₁t) in the normal phase + V_p1sin(ω₁t) negative carrier-V loaded on the positive fixed plate_p1sin(ω₁t) is loaded on the negative stator plate, wherein V_p1Is the amplitude, omega, of the positive and negative drive carriers₁The frequencies of the positive and negative drive carriers.

Further, the first synchronous demodulation module is represented by V_p1sin(ω₁And t) synchronously demodulating the obtained voltage signal by using the reference signal to obtain a direct current signal containing the displacement variation in the horizontal direction.

Further, the second synchronous demodulation module synchronously demodulates the obtained voltage signal by using the single-path driving carrier as a reference signal, so as to obtain a direct current signal containing a distance variation.

Further, the first synchronous demodulation module and the second synchronous demodulation module respectively comprise a band-pass filter, a multiplier and a low-pass filter which are connected in sequence.

Further, the charge amplifier comprises an operational amplifier, a feedback capacitor and a feedback resistor.

The invention also provides a double-axis capacitance displacement detection method based on a double modulation method, which comprises the following steps:

loading positive and negative driving carriers for modulating displacement change in the horizontal direction on a fixed polar plate of the capacitor;

loading a single-path driving carrier wave for modulating the direction of the change of the spacing on the fixed polar plate, and working together with the positive and negative driving carrier waves in a frequency division multiplexing mode;

converting differential capacitance signals caused by horizontal displacement and interval change into voltage signals;

and synchronously demodulating the voltage signals obtained by conversion to respectively obtain direct current signals containing displacement variation and space variation in the horizontal direction.

Go toStep, the form of the positive and negative driving carrier waves is +/-V_p1sin(ω₁t) in which V_p1Is the amplitude, omega, of the positive and negative drive carriers₁The frequency of the positive and negative drive carriers;

while performing said synchronous demodulation, with V_p1sin(ω₁t) synchronously demodulating the obtained voltage signal by using a reference signal to obtain a direct current signal containing displacement variation in the horizontal direction; and synchronously demodulating the obtained voltage signal by taking the single-path driving carrier as a reference signal to obtain a direct current signal containing the distance variation.

Through the technical scheme, compared with the prior art, the area-variable capacitance displacement detection and the distance-variable capacitance displacement detection are combined, and positive and negative driving carriers +/-V are added on the original positive and negative fixed polar plates_p1sin(ω₁t) and a carrier V_p2sin(ω₂t), two kinds of modulation exist in the structure, wherein the positive and negative driving carriers are used for adjusting the capacitance variation of the displacement of the brake polar plate relative to the horizontal direction of the fixed polar plate, and the added single-path carrier adjusts the capacitance variation of the distance between the brake polar plate and the vertical direction of the fixed polar plate in a frequency division multiplexing mode, so that the purpose of capacitance displacement detection in the horizontal direction and the vertical direction is achieved simultaneously in the mode. Compared with a single-axis capacitance displacement detection mode, the capacitance displacement detection method can detect the capacitance variation caused by the non-sensitive axis direction, and therefore the capacitance displacement detection precision is improved.

Drawings

FIG. 1 is a schematic diagram of a variable area capacitance displacement sensor;

FIG. 2 is a schematic diagram of a variable pitch capacitive displacement sensor;

FIG. 3 is a schematic diagram of the dual-axis capacitance displacement detection based on the dual modulation method according to the present invention;

reference numerals: 101 is a positive fixed plate, 102 is a negative fixed plate, 1 is a fixed plate, 2 is a movable plate, 3 is a first driving voltage module, 4 is a charge amplifier, 5 is a second driving voltage module, 6 is a first synchronous demodulation module, 601 is a first band-pass filter, 602 is a first multiplier, 603 is a first low-pass filter, 7 is a second synchronous demodulation module, 701 is a second band-pass filter, 702 is a second multiplier, and 703 is a second low-pass filter.

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. In addition, the technical features involved in the embodiments of the present invention described below may be combined with each other as long as they do not conflict with each other.

In the present invention, the term "horizontal direction" and "vertical direction" refer to the direction parallel to the movable and fixed plates of the capacitor, and the term "vertical direction" refers to the direction perpendicular to the plane of the movable and fixed plates.

Aiming at the defects of the prior art, the invention combines two modes, and the change of the distance is detected by adding one more modulation mode on the fixed polar plate, so that two kinds of change information of the movable polar plate relative to the fixed polar plate in the horizontal direction and the vertical direction can be obtained, and the purpose of double-axis capacitance displacement detection is achieved.

The embodiment of the invention discloses a double-axis capacitance displacement detection device based on a double modulation method, which comprises a fixedpolar plate 1, a positive fixedpolar plate 101, a negative fixedpolar plate 102, a movablepolar plate 2, a first driving voltage module 3, a seconddriving voltage module 5, a charge amplifier 4, a first synchronous demodulation module 6 and a second synchronous demodulation module 7, as shown in fig. 3. In the figure, the x axis is the horizontal detection direction, the y axis represents the horizontal swing axis direction, and the Z axis represents the vertical horizontal plane direction.

The positive fixedpole plate 101 and the negative fixedpole plate 102 are fixed on the outer frame in a parallel and staggered manner and are fixedly connected with the outer frame.

The movablepolar plate 2 can move in the horizontal and vertical directions, is arranged in a positive way with the fixedpolar plate 1, and forms a differential capacitor with the positive fixedpolar plate 101 and the negative fixedpolar plate 102; when the fixed polar plate and the movable polar plate are subjected to relative displacement in the horizontal direction or change of the distance in the vertical direction, a differential capacitance signal is generated. Thedynamic plate 2 connects the modulated capacitance signal to the charge amplifier 4.

The first driving voltage module 3 generates positive and negative driving carrier waves + V for adjusting the displacement variation of the brake polar plate relative to the fixed polar plate in the horizontal direction_p1sin(ω₁t) respectively loaded on the positive and negativefixed plates 101 and 102, wherein V_p1Is the amplitude, omega, of the positive and negative drive carriers₁The frequencies of the positive and negative drive carriers.

The seconddriving voltage module 5 generates a single-path driving carrier V for adjusting the distance variation of the brake polar plate relative to the vertical direction of the fixed polar plate_p2sin(ω₂t) is also loaded on said positive andnegative stator plates 101, 102, wherein V_p2Is the amplitude, ω, of the single drive carrier₂The frequency of the single drive carrier.

The charge amplifier 4 is connected with themovable electrode plate 2, and converts the modulated capacitance change signal into a voltage signal, so that subsequent demodulation and processing are facilitated.

The first synchronous demodulation module 6 is connected with V_P1sin(ω₁And t) is a reference signal, and the voltage signal after passing through the charge amplifier is demodulated to obtain a Direct Current (DC) quantity containing the displacement variation of the movable polar plate relative to the fixed polar plate in the horizontal direction.

Second synchronous demodulation module 7 with V_P2sin(ω₂And t) is a reference signal, and the voltage signal after passing through the charge amplifier is demodulated to obtain Direct Current (DC) containing the variable quantity of the vertical distance between the movable polar plate and the fixed polar plate.

Preferably, the first synchronous demodulation module 6 includes a first band-pass filter 601, afirst multiplier 602 and a first low-pass filter 603 which are connected in sequence, and the second synchronous demodulation module 7 includes a second band-pass filter 701, asecond multiplier 702 and a second low-pass filter 703 which are connected in sequence.

Preferably, the charge amplifier 4 comprises an operational amplifier, a feedback capacitor C_fAnd a feedback resistor R_f。

Preferably, the fixedpolar plate 1 and the movablepolar plate 2 are formed by sputtering deposition or machining; the differential capacitance signal can be amplified by a single or a plurality of arrayed arrangements.

Furthermore, themovable pole plate 2 can be connected with the outer frame through a spring, a sliding rod and the like, when the movable pole plate is displaced in the horizontal direction and the distance between the movable pole plate and the positive and negative fixed pole plates is changed in the vertical direction, the change of capacitance between the fixed pole plates is started, and the capacitance change is detected respectively, so that the change of displacement in the horizontal direction and the change of distance between the movable pole plate and the positive and negative fixed pole plates in the vertical direction can be obtained.

In the embodiment of the invention, two types of carrier waves +/-V are loaded on the positive fixedpolar plate 101 and the negative fixedpolar plate 102_p1sin(ω₁t) and V_p2sin(ω₂t) for modulating capacitance variation caused by displacement variation in the horizontal direction and capacitance variation caused by distance variation in the vertical direction between the movable and fixed plates, respectively, converting the differential capacitance signal into a voltage signal by the charge amplifier, and applying V to the voltage signal_p1sin(ω₁t) and V_p2sin(ω₂t) demodulating the reference signal and carrying out correlation processing to obtain the horizontal displacement variation and the vertical distance variation between the movable and fixed polar plates, thereby achieving the purpose of double-shaft capacitance displacement detection.

On the basis of the detection device, the embodiment of the invention also provides a double-axis capacitance displacement detection method based on a double modulation method, which comprises the following steps:

loading positive and negative driving carriers for modulating displacement change in the horizontal direction on a fixed polar plate of the capacitor;

loading a single-path driving carrier wave for modulating the direction of the change of the spacing on the fixed polar plate, and working together with the positive and negative driving carrier waves in a frequency division multiplexing mode;

converting differential capacitance signals caused by horizontal displacement and interval change into voltage signals;

and synchronously demodulating the voltage signals obtained by conversion to respectively obtain direct current signals containing displacement variation and space variation in the horizontal direction.

Further, the form of the positive and negative driving carriersIs +/-V_p1sin(ω₁t) in which V_p1Is the amplitude, omega, of the positive and negative drive carriers₁The frequency of the positive and negative drive carriers;

while performing said synchronous demodulation, with V_p1sin(ω₁t) synchronously demodulating the obtained voltage signal by using a reference signal to obtain a direct current signal containing displacement variation in the horizontal direction; and synchronously demodulating the obtained voltage signal by taking the single-path driving carrier as a reference signal to obtain a direct current signal containing the distance variation.

The basic principle of the present invention is briefly described below. The invention combines two detection modes, adds one path of single carrier modulation on positive and negative fixed polar plates, detects the change information of vertical spacing by frequency division multiplexing mode, and then changes the voltage output expression after passing through a charge amplifier into one

The voltage output expression obtained after the voltage signal converted by the charge amplifier passes through the first synchronous demodulation module is

The voltage output expression obtained after the voltage signal converted by the charge amplifier passes through the second synchronous demodulation module is

Through V₂The distance variation delta d of the movable polar plate relative to the vertical direction of the fixed polar plate can be directly obtained. At a voltage V₁And V₂The displacement change of the movable polar plate relative to the fixed polar plate in the horizontal direction can be obtained after the divisionMeasurement of

Generally speaking, the technical scheme of the invention combines two displacement detection modes, one modulation is added on the fixed polar plate loaded with positive and negative carriers, and the displacement variation of the movable polar plate relative to the fixed polar plate in the horizontal direction and the distance variation in the vertical direction can be obtained after subsequent demodulation and data processing are carried out on two signals. Compared with two original displacement detection modes, the method achieves the purpose of double-shaft capacitance displacement detection, and for single-shaft capacitance displacement detection, the method can obtain the influence brought by the direction of a non-sensitive shaft, so that the detection precision is improved.

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.

Claims (8)

Translated fromChinese

1.一种基于双调制法的双轴电容位移检测装置，其特征在于，包括：定极板、动极板、第一驱动电压模块、第二驱动电压模块、电荷放大器、第一同步解调模块和第二同步解调模块；1. a dual-axis capacitance displacement detection device based on dual modulation method, is characterized in that, comprises: fixed pole plate, moving pole plate, the first driving voltage module, the second driving voltage module, the charge amplifier, the first synchronous demodulation module and a second synchronous demodulation module;所述第一驱动电压模块产生用于调制水平方向位移变化的正负驱动载波，加载于所述定极板上；The first driving voltage module generates positive and negative driving carriers for modulating the displacement change in the horizontal direction, and loads them on the stator plate;所述第二驱动电压模块产生用于调制间距变化方向的单路驱动载波，也加载于所述定极板上，以频分复用的方式与所述第一驱动电压模块一起工作；The second driving voltage module generates a single-channel driving carrier wave for modulating the direction of pitch change, and is also loaded on the stator plate, and works together with the first driving voltage module in a frequency division multiplexing manner;所述电荷放大器与所述动极板相连，用于将水平方向位移及间距变化引起的差分电容信号转化为电压信号；The charge amplifier is connected with the moving plate, and is used for converting the differential capacitance signal caused by the horizontal displacement and the spacing change into a voltage signal;所述第一同步解调模块和所述第二同步解调模块用于对转化得到的所述电压信号进行同步解调，分别得到含有水平方向位移变化量和间距变化量的直流信号；The first synchronous demodulation module and the second synchronous demodulation module are used to perform synchronous demodulation on the voltage signal obtained by conversion, respectively, to obtain a DC signal containing a horizontal displacement variation and a spacing variation;所述定极板包括正定极板和负定极板；所述正定极板和负定极板以平行且交错的等间距阵列形式排布；The fixed pole plate includes a positive fixed pole plate and a negative fixed pole plate; the positive fixed pole plate and the negative fixed pole plate are arranged in a parallel and staggered equidistant array;所述第一驱动电压模块产生的所述正负驱动载波±V_p1sin(ω₁t)中，正相载波+V_p1sin(ω₁t)加载于所述正定极板上，负相载波-V_p1sin(ω₁t)加载于所述负定极板上，其中V_p1为所述正负驱动载波的幅值，ω₁为所述正负驱动载波的频率；In the positive and negative driving carriers ±V_p1 sin(ω₁ t) generated by the first driving voltage module, the positive-phase carrier +V_p1 sin(ω₁ t) is loaded on the positive fixed plate, and the negative-phase carrier -V_p1 sin(ω₁ t) is loaded on the negative stator plate, wherein V_p1 is the amplitude of the positive and negative driving carriers, and ω₁ is the frequency of the positive and negative driving carriers;所述第二驱动电压模块产生的所述单路驱动载波V_p2sin(ω₂t)，同样加载在所述正定极板和负定极板上，其中V_p2为所述单路驱动载波的幅值，ω₂为所述单路驱动载波的频率。The single-channel driving carrier V_p2 sin(ω₂ t) generated by the second driving voltage module is also loaded on the positive and negative stator plates, where V_p2 is the value of the single-channel driving carrier. Amplitude, ω₂ is the frequency of the single-channel drive carrier.2.如权利要求1所述的双轴电容位移检测装置，其特征在于，所述动极板与所述定极板呈正对状排布，组成差分电容。2 . The biaxial capacitance displacement detection device according to claim 1 , wherein the moving pole plate and the fixed pole plate are arranged in a face-to-face shape to form a differential capacitor. 3 .3.如权利要求1所述的双轴电容位移检测装置，其特征在于，所述第一同步解调模块以V_p1sin(ω₁t)为参考信号对所得的电压信号进行同步解调，从而得到含有水平方向位移变化量的直流信号。3. The biaxial capacitance displacement detection device according to claim 1, wherein the first synchronous demodulation module uses V_p1 sin(ω₁ t) as a reference signal to perform synchronous demodulation on the obtained voltage signal, Thereby, a DC signal containing the displacement variation in the horizontal direction is obtained.4.如权利要求1所述的双轴电容位移检测装置，其特征在于，所述第二同步解调模块以所述单路驱动载波为参考信号对所得的电压信号进行同步解调，从而得到含有间距变化量的直流信号。4. The biaxial capacitance displacement detection device according to claim 1, wherein the second synchronous demodulation module performs synchronous demodulation on the obtained voltage signal with the single-channel drive carrier as a reference signal, thereby obtaining A DC signal containing a pitch change.5.如权利要求1-4任一项所述的双轴电容位移检测装置，其特征在于，所述第一同步解调模块和所述第二同步解调模块均包括依次连接的带通滤波器、乘法器和低通滤波器。5. The biaxial capacitance displacement detection device according to any one of claims 1-4, wherein the first synchronous demodulation module and the second synchronous demodulation module both comprise band-pass filters connected in sequence multipliers, multipliers, and low-pass filters.6.如权利要求1-4任一项所述的双轴电容位移检测装置，其特征在于，所述电荷放大器包括运算放大器、反馈电容和反馈电阻。6 . The dual-axis capacitance displacement detection device according to claim 1 , wherein the charge amplifier comprises an operational amplifier, a feedback capacitor and a feedback resistor. 7 .7.一种基于双调制法的双轴电容位移检测方法，应用于如权利要求1-6任一项所述的双轴电容位移检测装置，其特征在于，包括以下步骤：7. A biaxial capacitance displacement detection method based on dual modulation method, applied to the biaxial capacitance displacement detection device as claimed in any one of claims 1-6, is characterized in that, comprises the following steps:在电容的定极板上加载用于调制水平方向位移变化的正负驱动载波；A positive and negative driving carrier for modulating the displacement change in the horizontal direction is loaded on the fixed plate of the capacitor;将用于调制间距变化方向的单路驱动载波，也加载于所述定极板上，以频分复用的方式与所述正负驱动载波一起工作；Loading the single-channel driving carrier used for modulating the direction of pitch change on the fixed pole plate, and working together with the positive and negative driving carriers in a frequency-division multiplexing manner;将水平方向位移及间距变化引起的差分电容信号转化为电压信号；Convert the differential capacitance signal caused by horizontal displacement and spacing change into a voltage signal;对转化得到的所述电压信号进行同步解调，分别得到含有水平方向位移变化量和间距变化量的直流信号。The converted voltage signal is synchronously demodulated to obtain a DC signal containing the displacement variation in the horizontal direction and the spacing variation respectively.8.如权利要求7所述的双轴电容位移检测方法，其特征在于，进行所述同步解调时，以V_p1sin(ω₁t)为参考信号对所得的电压信号进行同步解调，得到含有水平方向位移变化量的直流信号；以所述单路驱动载波为参考信号对所得的电压信号进行同步解调，得到含有间距变化量的直流信号。8 . The biaxial capacitance displacement detection method according to claim 7 , wherein when performing the synchronous demodulation, the voltage signal obtained is synchronously demodulated with V_p1 sin(ω₁ t) as a reference signal, 9 . A DC signal containing the displacement variation in the horizontal direction is obtained; and the obtained voltage signal is synchronously demodulated with the single-channel driving carrier as a reference signal to obtain a DC signal containing the spacing variation.

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