45 results about "Differential capacitance" patented technology

The application discloses a kind of foundation pit retaining pile construction casing precision control device and its construction method, device includes casing cylinder, pre-tightening connecting piece, insulating kettle, capacitive differential solution unit and opposite electrode array;Pre-tightening connecting piece is provided with closed interface cavity;Insulating kettle is contained in interface cavity, dielectric cavity is provided in insulating kettle, and filled with dielectric liquid insulation medium;Capacitive differential solution unit is sealed in interface cavity with insulating kettle;Opposite electrode array is attached to the inner wall of dielectric cavity, including at least two pairs of measuring electrodes being two by two oppositely arranged along the circumference of dielectric cavity.The capacitive differential sensing scheme of opposite electrode array and dielectric liquid insulation medium is used in the application, complementary differential capacitance signals are generated by the circumferential asymmetric change of dielectric free interface, so as to solve the deflection direction and inclination of casing, and the correction parameter set containing target adjustment direction and compensation amount can be directly generated to support directional correction operation.

The present invention relates to an accelerometer, which comprises a substrate and detecting devices. The substrate is provided with supporting anchor points and electrode fixing anchor points; the detecting device comprises two detecting plates and corresponding detecting electrodes, and the detecting electrodes are connected to the electrode fixing anchor points through connecting arms; the detecting plate is elastically connected to the supporting anchor point, the two detecting plates are asymmetrically arranged with respect to axes of the supporting anchor points, and the two detecting plates are parallel to each other and in opposite directions; and the detecting electrodes and the detecting plates are arranged at intervals to form a detecting capacitor. The wiring of in-plane detecting electrodes of different detecting devices can be separated, and wire crossing can be avoided to reduce the influence of parasitic capacitance caused by complex wiring, thus improving the detection accuracy of the accelerometer.

The invention relates to a fisheye terminal crystal slag prevention precision stamping machining control method. The method comprises the steps that a friction volt potential standard response is established based on a mold of a pre-machined micro-nano structure; a transient friction volt potential is collected in real time by using a suspension ground potential technology; a dynamic differential capacitance spectrum of the lubricating oil film is collected, and the molecular orientation order degree is analyzed; performing time sequence correlation analysis on the potential variation characteristic and the dispersion characteristic, and judging that the phase is a microscopic nucleation stage of the crystal slag when the polarity is detected to be overturned and the order degree is dropped; and the electrostatic minimal quantity lubrication system is triggered, and the charged oil mist is driven by a high-gradient electrostatic field induced by the micro-nano structure to be adsorbed to the friction hot spots in a targeted mode. The method has the advantages that the microcosmic early warning of crystal slag nucleation is realized, and self-aligned targeted lubrication is achieved.

The invention relates to the technical field of earthquake monitoring, in particular to a novel broadband geophone suitable for severe use environments, and is characterized in that a lower support piece is arranged on a lower fixed pole plate in a penetrating manner, a movable pole plate is arranged at the upper end of the lower fixed pole plate, a mass block is connected to the upper end of the movable pole plate, and two ends of the mass block are in contact with the upper support piece and the lower support piece respectively; a first capacitor is formed between the upper fixed plate and the upper side surface of the movable plate; and a second capacitor is formed between the lower fixed plate and the lower side surface of the movable plate. A first capacitor is formed between the upper fixed pole plate and the upper side face of the movable pole plate, a second capacitor is formed between the lower fixed pole plate and the lower side face of the movable pole plate, and when external vibration exists, the mass block drives the movable pole plate to move, so that the difference value of the first capacitor and the second capacitor is changed; the differential capacitor design can symmetrically counteract zero drift caused by temperature, full temperature range stability is achieved, temperature interference is reduced, and detection accuracy is improved.

A differential capacitance sensor signal detection device comprises: a first metal plate and a second metal plate arranged in parallel and oppositely, an intermediate capacitor arranged in parallel between the first metal plate and the second metal plate; an upper capacitor formed between the first metal plate and an upper plate of the intermediate capacitor; a lower capacitor formed between the second metal plate and a lower plate of the intermediate capacitor; the first metal plate and the second metal plate connected to a sinusoidal wave signal source; the intermediate capacitor connected in parallel to an external capacitor; the electric signals outputted by the upper plate and the lower plate of the intermediate capacitor connected to a phase-sensitive detector as measured signals via a superposition amplification circuit and a first coupling circuit; the electric signals outputted by the upper plate and the lower plate of the intermediate capacitor connected to the phase-sensitive detector as reference signals via a second coupling circuit and a comparison circuit; the output of the phase-sensitive detector connected to an output amplifier, and a signal related to the position of the intermediate capacitor is obtained. Accordingly, the reference signal and the measured signal in the phase-sensitive detection are the same frequency and the same phase.

The embodiment of the invention provides a differential capacitance displacement transducer. The differential capacitance displacement transducer comprises a sinusoidal oscillation circuit, a capacitor bank, an addition amplification circuit, a differential comparison circuit and a demodulation filtering amplification circuit, the sinusoidal oscillation circuit is used for generating a differential sinusoidal oscillation signal of which the peak-to-peak value is a positive and negative first voltage value and applying the differential sinusoidal oscillation signal to a first movable pole plate and a second movable pole plate of the capacitor bank; the addition amplification circuit is used for carrying out addition calculation on the differential sinusoidal signals output by the fixed pole plate of the capacitor bank and outputting sinusoidal signals; the differential comparison circuit is used for carrying out comparison calculation on the differential sinusoidal signal and outputting a square wave signal with the same phase as the differential sinusoidal signal; and the demodulation filtering and amplifying circuit is used for rectifying the sinusoidal signal by using the square signal, filtering and amplifying the rectified sinusoidal signal, and outputting a detected vibration voltage signal. According to the differential capacitance displacement transducer, detection of tiny vibration signals can be achieved, noise interference is reduced, and the detection precision is improved.

This invention discloses a method for identifying coal and coal gangue based on capacitance tomography. It utilizes a differential capacitance tomography electrode sensor to collect capacitance measurement data of coal, coal gangue, or mixtures thereof within the measured area. Direct coupling capacitance between electrodes is canceled by applying an inverse excitation signal. The raw data is preprocessed, and stable and valid capacitance measurements are selected to form a data vector. A regularized iterative algorithm is used to solve for the dielectric constant distribution, combining a preset sensitivity distribution function. An initial solution is obtained through regularization, and then iteratively updated until convergence. Image reconstruction is performed based on the dielectric constant distribution. After normalization and edge detection, a capacitance tomography image representing the location, size, and dielectric differences of the materials is generated. The image grayscale values ​​are analyzed, and coal and coal gangue regions are automatically identified and marked according to a preset dielectric constant threshold range. Simultaneously, their centroid coordinates and equivalent areas are calculated, achieving non-destructive and accurate identification of the mixture components.

A method for detecting and adaptively compensating for ultra-low frequency weak vibrations in a MEMS accelerometer includes: a multi-channel parallel coherent modulation and demodulation module acquiring differential capacitance signals of the sensitive units in the MEMS accelerometer through n parallel coherent detection links, and then synchronously modulating and coherently demodulating the differential capacitance signals to obtain n baseband signals; an adaptive weighted fusion module evaluating the signal-to-noise ratio (SNR) of each baseband signal, and then weighting and fusing the n baseband signals using the square of the SNR as a weighting coefficient to obtain a fused signal; a dynamic temperature drift compensation module performing temperature drift compensation on the fused signal to obtain a compensated signal; and a variational mode decomposition adaptive filtering module performing adaptive filtering on the compensated signal to output the final acceleration signal. The effect is to improve the detection of ultra-low frequency weak vibrations in a MEMS accelerometer and enhance the accuracy of wide-temperature-range dynamic temperature drift compensation.

The application relates to the technical field of aluminum alloy stamping die detection, and specifically discloses a fatigue test device and a test process for an aluminum alloy stamping die. The device comprises multiple sets of elastic supporting assemblies and multiple sets of elastic pressing assemblies which are distributed below the die and above the die. The elastic supporting assemblies and the elastic pressing assemblies realize stress-free, self-adaptive and stable clamping of the complex stamping die. Meanwhile, the orthogonal three-axis guide rail drives the detection probe to realize programmed precise movement in the three-dimensional space, so that the detection probe can reach every concave-convex area of the die surface without dead angle to perform scanning, thereby providing a stable workpiece posture and an accurate probe path for high-precision detection from the physical level, and overcoming the bottleneck that large special-shaped workpieces are difficult to be stably clamped and comprehensively detected. The device also integrates a double-physical-field sensing mechanism of eddy current and differential capacitance, and synchronously analyzes the eddy current impedance signal and the differential capacitance signal, so that the detection equipment has the ability to distinguish the base crack and the surface aluminum adhesion.

Provided in the present invention are a differential capacitance diaphragm vacuum gauge and a production device therefor. The vacuum gauge comprises a housing, a fixed electrode plate and a diaphragm, wherein the housing is provided with a gas intake pipe and a gas filling pipe; the fixed electrode plate is arranged inside the housing; the diaphragm is arranged inside the housing, and divides the interior of the housing into an upper chamber and a lower chamber; the fixed electrode plate is located in the upper chamber, and a preset distance is provided between the fixed electrode plate and the diaphragm; the lower chamber is in communication with the gas intake pipe and forms an open measurement chamber; the gas filling pipe is in communication with the upper chamber and forms a closed reference chamber; and a preset volume of gas filled by means of the gas filling pipe is provided in the closed reference chamber, so that the closed reference chamber is in a preset positive high-pressure state. The closed reference chamber is filled with gas to a certain pressure by means of the gas filling pipe, so that the reference chamber is in a constant high-pressure state, thereby achieving a simple structure and the effect of easy manufacturing.

The invention discloses a design method of a differential compensation electromagnetic metamaterial array, and belongs to the technical field of artificial electromagnetic materials. Firstly, basic structure parameters of the electromagnetic metamaterial are calculated according to a selected structure and resonance frequency, element simulation is carried out in Maxwell to obtain self-inductance of the electromagnetic metamaterial, and differential capacitance compensation is carried out according to the electromagnetic effect of elements. According to the invention, the low-frequency electromagnetic metamaterial is introduced into the magnetic coupling resonant wireless power transmission system, and through a differential compensation strategy, the overall resonant frequency deviation of the array is effectively suppressed, so that the system stably works at a target frequency and shows a stable negative magnetic conductivity characteristic; the problems of low transmission efficiency and poor stability under low frequency caused by coupling change between coils are solved.

The invention provides a capacitive pressure sensor and a preparation method thereof, and belongs to the technical field of pressure detection, the capacitive pressure sensor comprises a vertical differential capacitance structure, the vertical differential capacitance structure comprises a reference pole plate, a middle pole plate and a pressure sensing film, and the middle pole plate is located between the reference pole plate and the pressure sensing film; the metal supporting structure is used for supporting the vertical differential capacitor structure; the middle pole plate is directly bonded with the reference pole plate and the pressure sensing film through laser, and the metal supporting structure is directly bonded with the vertical differential capacitor structure through laser. Through a vertical differential capacitor structure and a laser direct bonding process, the defects that structural errors cannot be eliminated and polar plate gaps are uncertain due to warping of a diaphragm are overcome, original errors caused by the structure are reduced, sealing materials are omitted, and the control precision of the distance between polar plates of the capacitive pressure sensor is improved.

The invention belongs to the technical field of accelerometers, and particularly relates to a reading circuit for an accelerometer and an accelerometer module. In the reading circuit, a temperature compensation module outputs a temperature compensation signal according to the temperature change of a target accelerometer; the controller outputs a first driving signal and a second driving signal for voltage amplitude adjustment according to the first driving signal and the second driving signal; the front-end chopping switch performs chopping modulation on the first driving signal and the second driving signal and outputs a first driving square wave and a second driving square wave to the target accelerometer; the CV module converts a differential capacitance change signal output by the target accelerometer based on the first driving square wave and the second driving square wave into a differential voltage change signal; the rear-end chopping switch is used for carrying out chopping demodulation on the differential voltage change signal and outputting a differential demodulated voltage signal; and the filtering module carries out filtering processing on the differential de-modulated voltage signal and outputs a differential pole plate voltage signal, so that an accelerometer signal output scheme with high precision, low noise and low total temperature zero offset is realized.

The invention discloses a capacitance floating unit shear stress chip with acceleration detection and compensation functions, and relates to a shear stress measurement chip. According to the chip, the displacement response of the floating unit under the action of incoming flow shear stress is detected by using the differential capacitor comb teeth, and then the shear stress is calculated. The chip comprises a capacitance sensitive layer, a shielding layer and a shear stress sensitive layer from top to bottom. The chip is provided with two groups of floating units, one group of floating units senses the shear stress, and the other group of floating units senses the acceleration, so that the synchronous detection and compensation function of the shear stress and the acceleration in a single chip can be realized. And the influence of the external environment on the comb tooth structure of the differential capacitor is avoided through the buried design, and the range is widened and the detection stability is improved through the closed-loop electrostatic driving force. The chip has the characteristics of high-precision shear stress detection, internal acceleration detection and decoupling.

The invention relates to the field of accelerometers, in particular to a vertical variable-area differential capacitive accelerometer, which comprises an external frame, a flexible support beam assembly, a sensitive mass block and an interdigital capacitor electrode, the sensitive mass block and the external frame form a symmetrical suspension type rigid connection structure through a flexible supporting beam assembly, and the upper side and the lower side of the symmetrical suspension type rigid connection structure are respectively provided with interdigital capacitance electrodes; the interdigital capacitor electrode comprises a plurality of movable electrode plates which synchronously move along with the sensitive mass block, and a plurality of fixed electrode plates which are fixed on the external frame and are arranged with the plurality of movable electrode plates in a penetrating manner; when the sensitive mass block generates displacement under the action of acceleration in the z-axis direction, the sensitive mass block drives the movable electrode plates on the upper side and the lower side of the sensitive mass block to move relative to the corresponding fixed electrode plates, so that the lateral effective overlapping areas of the interdigital capacitor electrodes on the upper side and the lower side of the sensitive mass block respectively generate linear changes in opposite directions; therefore, a differential capacitance signal in a linear relation with the displacement of the sensitive mass block is output.

The embodiment of the invention provides a signal processing method and system for a capacitive accelerometer of a micro electro mechanical system, and the method comprises the steps: detecting a capacitance change caused by acceleration through a differential capacitance structure, and obtaining a differential capacitance variation; inputting the differential capacitance variable quantity into a trans-impedance amplifier, converting the differential capacitance variable quantity into voltage change data, and superposing the voltage change data with a direct current bias voltage to generate a baseband modulation signal; a square wave carrier generation unit generates a square wave carrier signal, and modulates the baseband modulation signal and the square wave carrier signal to generate a modulation signal; synchronously demodulating the modulation signal through an annular diode demodulation circuit and outputting two paths of signals; performing low-pass filtering on the two paths of signals to filter out high-frequency carrier components and reserve low-frequency acceleration signals; and carrying out differential operation on the two paths of filtered signals, outputting a target voltage signal which is in a linear relation with the acceleration, and carrying out constant gain conversion by maintaining the signal processing link.

The application provides a differential capacitance data reading circuit and a MEMS capacitance data reading method, and relates to the technical field of electronic circuits, in which a differential capacitance input interface is directly connected with a MEMS sensor to receive two-way differential capacitance input signals provided by the MEMS sensor; an excitation signal control module is coupled to the differential capacitance input interface to generate two-way excitation control signals corresponding to the differential capacitance input signals based on external enable signals generated by the MEMS sensor; a differential capacitance current conversion module is coupled to the differential capacitance input interface to convert the differential capacitance input signals into differential current signals based on the excitation control signals; and a differential current output interface is coupled to the differential capacitance current conversion module to output the differential current signals, so as to determine the differential capacitance value of the MEMS sensor. The circuit and the method provided by the application can effectively realize low-noise and high-precision measurement of the output capacitance signals of the MEMS sensor.

The invention relates to the technical field of semiconductor device photoelectric performance testing, and discloses a high-sensitivity heterojunction spectrum detection system and a data acquisition method thereof, and the system comprises a bias voltage control unit, a signal acquisition unit, a digital processing unit and an upper computer processing unit. The digital processing unit adopts a trapezoidal hysteresis scanning strategy, and utilizes a transient shielding window and asymmetric residence time to induce charge hysteresis; and performing synchronous demodulation on the current response through a parallel channel, extracting differential conductance, differential capacitance and second harmonic components, and correcting a system phase error by using a rotation matrix. The upper computer processing unit constructs an augmented matrix based on multi-dimensional physical parameters, combines a physical kernel function, and utilizes a mixed regularization algorithm with smooth and sparse constraints to invert and calculate an interface state density distribution spectrum. According to the method, the problems of large signal scanning interference and inversion ill-conditioned conditions in general detection are solved, and high-precision quantitative characterization of interface state defects is realized.

This application relates to the field of battery technology, specifically to a positive electrode active material, a secondary battery, and an electrical device. In the discharge differential capacitance curve of the positive electrode active material of this application, the ratio of the dQ / dV values ​​of the peak P1 between 3.5 and 3.6V and the peak P2 between 3.6 and 3.9V meets a certain range. This allows the positive electrode active material to have lower impedance while maintaining higher capacity, reduces heat generation during fast charging, improves battery safety performance, and the lower impedance can also slow down battery capacity decay and improve battery cycle life.

The application provides a kind of micro-mechanical acceleration detection structure for automobile safety air bag, belongs to acceleration detection technical field, including substrate, movable mass block frame and cover plate, movable mass block frame is horizontally arranged between substrate and cover plate;Movable mass block frame is provided with four quadrant frames, movable mass block anchor point is arranged in the length direction in the quadrant frame, movable mass block anchor point is provided with support part connected with the quadrant frame, the lower end of movable mass block anchor point is fixed on the substrate;The middle part of movable mass block frame inside is provided with a plurality of movable combs, fixed detection comb is arranged between adjacent movable combs, fixed detection comb is provided with fixed comb anchor point, the lower end of fixed comb anchor point is fixed on the substrate, and the differential capacitance detection gap is formed between fixed detection comb and movable comb.The micro-mechanical acceleration detection structure for automobile safety air bag provided by the application adopts a brand-new frame structure and layout form, which greatly improves the reliability of the accelerometer.

The application discloses a wide-range electric field measurement method, device, equipment and medium of a liquid metal probe, and relates to the technical field of electric field measurement. The method comprises the following steps: acquiring a real-time differential capacitance signal output by a differential capacitance detection electrode; obtaining a real-time displacement and an offset direction of a liquid metal droplet relative to an initial equilibrium position according to a pre-labeled capacitance-displacement corresponding relationship; combining the real-time displacement obtained through continuous sampling to obtain a real-time displacement change rate along the current offset direction; when the absolute value of the real-time displacement reaches a preset displacement threshold value or the predicted wall-touching time is not greater than a preset time threshold value, determining an application mode of a compensation electrode and a direct-current control bias voltage according to a bias compensation relationship; applying the voltage and acquiring a controlled residual differential capacitance; and finally calculating an electric field intensity measurement value in the sensitive axis direction. The application can inhibit the saturation of the liquid metal droplet touching the wall under a strong electric field and realize wide-range electric field measurement without increasing the size of the elastic cavity of the liquid metal probe.

The application discloses a modeling method for optimizing electric field coupling noise of a quartz flexible accelerometer, and comprises the following steps: constructing a closed loop system of a quartz flexible accelerometer table head, including a quartz pendulum piece assembly, a variable-pole-distance differential capacitor sensor, a differential capacitor detection circuit, a torque motor control system and a torque motor; the closed loop system comprises an electric field coupling system, including internal distribution capacitance between a torque motor coil and the differential capacitor sensor, the variable-pole-distance differential capacitor sensor, the differential capacitor detection circuit and the torque motor control system, and a model of the internal distribution capacitance is constructed; the internal distribution capacitance is considered, a transfer function of the electric field coupling system is calculated when a torque motor driving signal is regarded as a noise source; and then a transfer function of the accelerometer closed loop system considering the electric field coupling noise is solved. The modeling method considers the electric field coupling noise inside the accelerometer table head, reduces measurement error and improves the performance of an inertial navigation system.

The present application belongs to the field of instruments and internet of things monitoring technology, and particularly relates to a wireless liquid level remote monitoring liquid level meter and a monitoring system, aiming to solve the problems of insufficient temperature resistance, hanging material interference, low precision and poor stability caused by lack of automatic calibration in high-temperature molten salt liquid level measurement. The system comprises a 1000 DEG C-resistant double-layer coaxial capacitance sensing probe, an adaptive signal conditioning module, a wireless transmission unit, a remote monitoring terminal and a dynamic calibration engine. The signal precision is improved by suppressing hanging material through a porous ceramic electrode, differential capacitance and temperature compensation. Based on the dielectric properties of molten salt, online calibration without manual intervention is realized. Remote visualization and intelligent alarm are supported, and the system is suitable for extreme working conditions such as solar thermal power generation.

This invention discloses a digital closed-loop control and measurement circuit for a quartz flexible accelerometer. It includes a differential capacitor carrier demodulation and detection circuit, a low-pass filter amplifier circuit, a first A / D converter, an FPGA, a D / A converter, and a power amplifier circuit connected in sequence to achieve low-noise digital closed-loop control. The set value of the D / A converter reflects the current acceleration measurement. It also includes a sampling resistor, a zero-drift amplifier circuit, a second A / D converter, and an FPGA connected in sequence to form a zero-drift current measurement circuit driving the meter's torque coil. The measurement value of the second A / D converter also reflects the current acceleration measurement. The FPGA simultaneously obtains the set value of the D / A converter and the measurement value of the second A / D converter, digitally outputting a low-noise, zero-drift acceleration characterization value. This invention effectively solves the problems of poor temperature drift characteristics, large zero-point error, and large scale factor error in ordinary digital closed-loop quartz accelerometers, significantly improving the accuracy of digital quartz accelerometers.

The application discloses a MEMS sound wave sensor with scalar and vector composite sensing and a manufacturing method thereof, and belongs to the technical field of micro-electro-mechanical systems. The piezoelectric film, the scalar lower lead wire area and the scalar upper lead wire area constitute a piezoelectric MEMS sensor for sensing scalar sound wave information; the upper plate vector lead wire area, the upper plate, the upper plate lower insulating layer, the upper plate limiting concave frame, the upper plate anti-collision convex point, the back-shaped upper cantilever beam group, the vector lead wire area, the back-shaped lower cantilever beam group, the mass block, the support frame, the lower plate upper insulating layer, the lower plate limiting concave frame, the lower plate anti-collision convex point, the lower plate, the lower plate vector lead wire area constitute a sandwich type differential capacitance MEMS sensor for sensing vector sound wave information. The application has the advantages of scalar and vector composite sensing, small volume, large range, high sensitivity, high reliability, high integration, low cost, low noise, stable performance and the like.

The embodiment of the invention discloses a capacitance type ship cylinder sleeve abrasion monitoring device and method, differential capacitance is obtained through two movable pole plates and a fixed pole plate which are arranged in a sealing box, the differential capacitance is converted into a digital signal through a capacitance-digital converter, and the inner diameter of a cylinder sleeve is obtained through a signal processing and control unit. Abrasion monitoring of the cylinder sleeve of the large two-stroke diesel engine for the ship is achieved in an auxiliary mode. According to the invention, measurement can be completed by using the existing scavenging port and piston movement under the condition of no cylinder hanging, the ceramic ball is abutted against and separated from the inner wall of the cylinder sleeve by using the tensioning mechanism, the ceramic ball can be prevented from scratching the inner wall of the cylinder sleeve, and the whole device is adjusted through inclination and rotation two degrees of freedom through the inclination auxiliary device and the slewing bearing, so that the measurement precision is improved. And the monitoring accuracy can be improved by accurate leveling. By adopting capacitive differential measurement, submicron resolution can be realized, the device is not influenced by oil film and material magnetism, and compared with a traditional mechanical measuring instrument, the device is high in precision and quick in response, and does not need an additional calibration medium.

The application provides a quartz tuning fork gyroscope, comprising a tuning fork structure, a first cover plate and a second cover plate; the tuning fork structure is clamped between the first cover plate and the second cover plate, and the tuning fork structure comprises a tuning fork body and an outer frame, and the tuning fork body is built in the outer frame; the tuning fork body comprises a pair of driving parts, a pair of detecting parts, a connecting beam and a coupling beam, one end of the coupling beam is connected with the pair of driving parts, the other end is connected with the pair of detecting parts, and the tuning fork body is connected with the outer frame through the connecting beam; the detecting part comprises a detecting fork finger and a detecting hammer head connected with the detecting fork finger; the detecting fork finger has opposite first opposite surfaces, the first opposite surfaces are provided with first detecting electrodes, the detecting hammer head has opposite second opposite surfaces, and the second opposite surfaces are provided with second detecting electrodes; one side of the first cover plate facing the tuning fork structure is provided with third detecting electrodes, and one side of the second cover plate facing the tuning fork structure is provided with fourth detecting electrodes, so that differential capacitance type detection is realized, and the detection precision of the quartz tuning fork gyroscope is improved.

The application provides a capacitive micromachined accelerometer. The capacitive micromachined accelerometer comprises a substrate with anchor points, at least one detection structure pair arranged on one side of the substrate and elastically connected to the anchor points, and a detection electrode arranged in parallel with the detection structure pair, wherein the detection structure pair comprises two seesaw structures respectively elastically connected to the substrate, the seesaw structures are asymmetric with respect to the rotation axes of the anchor points, and the asymmetric parts of the two seesaw structures are opposite and parallel; when a detection mode is detected, the sizes of the intervals formed by the two seesaw structures and the detection electrode change in opposite directions. When the accelerometer is affected by rotational angular acceleration noise, the two seesaw structures will rotate and tilt in the same direction with the corresponding anchor points as the rotation axes, which will cause common-mode changes of the differential capacitance and offset the influence, thereby reducing the influence of external rotational angular acceleration noise or external factors such as stress on the detection of the accelerometer and improving the detection precision.

The application discloses a 24-spring three-dimensional equal-force scanning probe, which comprises a probe mounting base, a circuit processing module, a signal amplification module, a probe body, a balance spring, a trigger switch, a probe seat, a probe connector, a probe, a probe ball, a magnetic attraction structure, an x-direction guiding mechanism, a y-direction guiding mechanism and a z-direction guiding mechanism. In the application, 24 elastic springs are used in the three guiding mechanisms. Except that the two groups of elastic springs in the z-direction guiding mechanism are of the same size, the two groups of elastic springs in the x-direction guiding mechanism and the y-direction guiding mechanism are of different sizes. Through stress analysis and optimization design, three-dimensional equal-force measurement of the three-dimensional scanning probe can be realized. In the application, the three guiding mechanisms are all provided with differential capacitance sensors and two groups of unequal-area plate capacitance sensors arranged in quadrature, so that redundant measurement of six degrees of freedom of the guiding mechanisms can be realized. The device has wide application, and is especially suitable for high-precision scanning probes.

The application discloses a kind of battery differential capacitance calculation methods, the method comprises: based on the frequency interval of pre-set electrochemical impedance spectrum test is carried out to battery, obtain the original impedance spectrum data of the battery under the frequency interval, screen out inductance data to obtain test impedance spectrum data in the original impedance spectrum data;Based on the test impedance spectrum data obtains the test capacitive reactance spectrum data under the frequency interval;Based on the regularization method, the theoretical capacitive reactance spectrum data of the battery under different relaxation time is calculated, based on the test capacitive reactance spectrum data, the theoretical capacitive reactance spectrum data and the minimum target method calculates the differential capacitance data of the battery under different relaxation time.The technical scheme provided in the application can solve the technical problems that the differential capacitance data is difficult to be accurately obtained when the battery is in different relaxation time in the prior art electrochemical impedance spectrum test.