72 results about "Differential capacitance" patented technology

The invention discloses a variable-area capacitive sensor displacement measurement method for suppressing interference, and relates to the technical field of precision displacement detection, and the method comprises the steps: S1, obtaining a differential capacitor array through a variable-area capacitive sensor; s2, acquiring a capacitance change signal by using the differential capacitor array; and S3, performing differential processing on the capacitance change signal to obtain a displacement measurement result of the variable-area capacitive sensor. According to the invention, a plurality of groups of differential capacitor pairs are arranged in the same direction, and differential output is carried out after odd-even grouping parallel connection, so that the output signal of the sensor is linearly increased along with the increase of the number of the differential capacitor pairs, and the measurement sensitivity is effectively improved. The structure not only can make quick and accurate response to infinitesimal displacement change, but also can realize higher-precision detection capability on the premise of not obviously increasing system complexity.

The invention discloses a pilot protection method and device based on instantaneous power total and incremental waveform similarity, and belongs to the technical field of power systems. According to the method, fault detection is started through voltage or current abrupt change, differential capacitance current compensation is carried out based on a full current sampling value, and a compensated voltage value is calculated by combining an electromagnetic wave transmission equation and a line Bergeron model so as to eliminate the influence of line parameters; and judging a passive load branch fault through a current amplitude and an integral value, otherwise, synchronously adopting an instantaneous power full-quantity waveform cosine similarity longitudinal main protection criterion and an instantaneous power increment waveform cosine similarity criterion to identify an internal fault, and overcoming a reliability'dead zone 'defect caused by near-zone fault voltage drop. The method does not need to depend on power frequency phasor calculation, and can improve the sensitivity and reliability of protection in scenes of a high-proportion new energy power grid, a micro-grid and the like.

The application discloses a variable-area capacitive sensor displacement measurement method for interference suppression and relates to the technical field of precise displacement detection, and comprises the following steps: S1, acquiring a differential capacitance array by using a variable-area capacitive sensor; S2, acquiring a capacitance change signal by using the differential capacitance array; and S3, performing differential processing on the capacitance change signal to acquire a variable-area capacitive sensor displacement measurement result. The application arranges multiple groups of differential capacitance pairs in the same direction, adopts a processing mode of odd-even grouping and parallel connection and then differential output, so that the output signal of the sensor linearly increases with the increase of the number of differential capacitance pairs, and the sensitivity of measurement is effectively improved. The structure can not only quickly and accurately respond to slight displacement changes, but also realize higher-precision detection capability without significantly increasing the complexity of the system.

The utility model relates to the technical field of mother and baby products, in particular to a breast pump. The breast pump comprises a milk storage container and three differential capacitance sensor assemblies. In the rising direction of the liquid level of milk in the milk storage container, the first detection electrode assembly of the first differential capacitance sensor assembly is arranged in the top area; a second detection electrode assembly of the second differential capacitance sensor assembly is arranged in the bottom area; the height of the top of a third detection electrode assembly of the third differential capacitance sensor assembly is lower than that of the first detection electrode assembly, and the height of the bottom of the third detection electrode assembly is higher than that of the second detection electrode assembly. According to the breast pump, the milk storage container is detected through the three differential capacitance sensor assemblies, the state of the milk storage container can be comprehensively determined in detail, the intelligent degree of the breast pump can be improved, interference can be effectively resisted through the differential capacitance sensor assemblies, and the detection accuracy is guaranteed.

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 invention discloses a mesothermodynamic model-based electrode electrolyte interface property prediction method. The method comprises the following steps of S1, establishing a mesothermodynamic model of an electrode electrolyte interface; step S2, constructing a DeepMT model based on a DeepONet framework; step S3, generating a training data set through the mesothermodynamic model, and training DeepONet by using an Adamax optimizer; s4, obtaining ion density distribution based on the trained DeepMT model, and calculating the interfacial adsorption capacity, the surface charge and the differential capacitance; and S5, combining the ion density distribution prediction phase diagram and the electrolyte shielding effect, and analyzing the interface behavior in the complex electrochemical environment. According to the method, the calculation efficiency of the mesothermodynamic model is improved by 2-4 orders of magnitude, and a theoretical tool is provided for optimization design of a supercapacitor, a battery and an electro-catalysis interface.

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 invention discloses a wafer surface film thickness on-line detection method and device, and the method comprises the steps: transmitting a grating signal to a wafer through a grating device, receiving a reflection signal outputted by the reflection of the grating signal on the surface of the wafer, and judging whether the wafer is in a horizontal state or not; if yes, when the wafer is driven to rotate for spin coating treatment, alternately applying excitation signals to the first capacitive sensor and the second capacitive sensor; acquiring a differential capacitance value between the first capacitive sensor and the second capacitive sensor in real time, and synchronously acquiring dynamic gaps between the wafer and the first capacitive sensor and between the wafer and the second capacitive sensor; and according to the differential capacitance value, the dynamic gap and the dielectric constant of the film layer material coated on the surface of the wafer, the thickness distribution of the film layer on the surface of the wafer is analyzed and calculated through impedance spectroscopy. According to the invention, the precision of wafer surface film thickness detection can be effectively improved, and the problem that the precision is not high when a capacitance sensor is adopted to carry out capacitance detection on the wafer surface film in the prior art is solved.

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 present invention relates to a capacitance measurement device and method for a capacitor array in a chip. By optimizing the design of a traditional capacitance measurement circuit and adopting a differential capacitance measurement technology based on the mutual capacitance of vertical and horizontal lines, the tolerance between each two mutual capacitances is processed and analyzed to improve the ability to capture tiny capacitance changes. By applying excitations of opposite phases to adjacent transmitting electrodes, the capacitance difference is extracted using the current cancellation principle, effectively eliminating the influence of circuit device process deviations and ambient temperature drift. A differential capacitance measurement module is used to convert nA-level composite current signals into voltages, and high-pass and low-pass filtering are combined to eliminate DC offsets and ensure signal stability under high gain. A frequency domain signal processing module is used to extract the amplitude and phase of the excitation, convert the analog signal into a digital signal, minimize the noise impact, and generate a high-entropy key. The measurement results are highly robust and accurate, and have strong anti-interference capabilities.

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 present application relates to a kind of micromechanical capacitance compensation structure and its preparation method, the capacitance compensation structure is in the shape of cylinder, cone, platform or inverted crater, be arranged in capacitor plate inside, for changing capacitance.When being arranged below the plate, recess is formed by depositing sacrificial layer and patterning on the lower plate structure layer;Depositing thin film material, etching to remove the surface medium thin film material of sacrificial layer, retaining the medium material in recess;Depositing capacitor upper plate structure layer thin film material, and patterning is formed release hole;After releasing the sacrificial layer through release hole, the compensation capacitance structure is obtained.When being arranged above the plate, convex structure is formed by etching to form thin film material on the lower plate structure layer of capacitor;Depositing and planarizing sacrificial layer;Depositing capacitor upper plate and patterning is formed release hole;After releasing the sacrificial layer through release hole, the compensation capacitance structure is obtained.The present application realizes capacitance matching and compensation, especially for differential capacitance structure, reaches the effect of upper and lower symmetrical capacitance structure.

The invention provides an MEMS pressure sensor, a manufacturing method thereof and an electronic device, and the method comprises the steps: providing a first substrate, forming at least one first pressure structure on the surface of the first substrate, and enabling the first pressure structure to comprise a first electrode layer and a first sacrificial layer from bottom to top, and a first cavity which penetrates through the first sacrificial layer and exposes the first electrode layer; a second substrate is provided, second pressure structures corresponding to the first pressure structures in number are formed on the surface of the second substrate, and each second pressure structure comprises a second electrode layer, a second sacrificial layer and a third electrode layer from bottom to top; bonding the first sacrificial layer and the third electrode layer, and removing the second substrate to expose the second electrode layer; a plurality of first release holes penetrating through the second electrode layer and a second cavity penetrating through the second sacrificial layer and arranged corresponding to the first cavity are formed, the first release holes are exposed out of the second cavity, the first electrode layer and the third electrode layer form a first variable capacitance structure, and the second electrode layer and the third electrode layer form a second variable capacitance structure. According to the scheme, the first pressure structure and the second pressure structure are bonded to form the differential capacitance type pressure sensor, namely, the first variable capacitance structure and the second variable capacitance structure are formed, pressure is measured through differential output of the first variable capacitance structure and the second variable capacitance structure, the measurement precision is higher, and the measurement precision is higher. And thus, the performance of the MEMS pressure sensor can be improved.

The utility model relates to the technical field of mother and baby products, in particular to a breast pump. The breast pump comprises a milk storage container and three differential capacitance sensor assemblies. The first differential capacitance sensor assembly comprises a first detection electrode assembly, and the first detection electrode assembly is arranged at the bottom in the rising direction of the milk liquid level; the second differential capacitance sensor assembly comprises a second detection electrode assembly, and the second detection electrode assembly is arranged at the top in the rising direction of the milk liquid level; the third differential capacitance sensor assembly comprises a third detection electrode assembly, and the third detection electrode assembly is arranged between the first detection electrode assembly and the second detection electrode assembly in the milk liquid level rising direction. According to the breast pump, the milk storage container is detected through the three differential capacitance sensor assemblies, the state of the milk storage container can be comprehensively determined in detail, the intelligent degree of the breast pump can be improved, interference can be effectively resisted through the differential capacitance sensor assemblies, and the detection accuracy is guaranteed.

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.

An MEMS capacitive planar micro-force sensor based on a bistable mechanical structure comprises a bottom silicon layer, a middle oxidation insulating layer and a top silicon structure layer, a sensor sensitive structure is arranged in the top silicon structure layer and comprises a probe structure, the rear end of the probe structure is connected with an internal mass block, the internal mass block is connected with an internal supporting beam, and the internal supporting beam is connected with an external supporting beam. The internal supporting beam is connected with the external mass block, the external mass block is connected with the external supporting beam, and the probe structure, the internal mass block, the internal supporting beam and the external mass block form a sensor movable structure; the external supporting beam is connected with the supporting beam frame; the two sides of the probe structure are differential capacitance comb tooth arrays at the front part of the sensor, the two sides of the internal supporting beam are differential capacitance comb tooth arrays at the middle part of the sensor, the outer side of the external mass block is a differential capacitance comb tooth array at the rear part of the sensor, and the fixed comb tooth array is connected with a comb tooth cantilever frame; according to the invention, precise detection of planar biaxial sub-nN magnitude micro force can be realized at the same time.

The present application relates to a capacitance mismatch detection circuit, method and detection device. The capacitance mismatch detection circuit is connected to the differential capacitance structure of the accelerometer, and the capacitance mismatch detection circuit includes an input circuit and a controller; the input circuit is respectively connected to the upper plate of the differential capacitance structure and the lower plate of the differential capacitance structure, the output end of the controller is connected to the input circuit, and the input end of the controller is connected to the middle plate of the differential capacitance structure; the input circuit is used to obtain an input signal and apply a voltage to the upper and lower plates of the differential capacitance structure according to the input signal; the controller is used to obtain the output signal of the middle plate of the differential capacitance structure, and when the output signal meets a preset condition, the capacitance mismatch quantization value of the differential capacitance structure is determined according to the input signal. The use of the capacitance mismatch detection circuit can realize the detection of the intrinsic capacitance mismatch value of the capacitive MEMS accelerometer.

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 present invention belongs to the technical field of ring-type micromechanical gyroscopes and discloses a control structure and method for frequency tuning of a ring-type mechanical gyroscope. The structure comprises: a first adder, a mechanical transfer function unit, a detection mode differential capacitance detection unit, a second adder, a detection mode circuit gain module, a multiplier, a tuning channel controller, a tuning channel circuit gain module, a third adder, and a detection mode closed-loop controller. The first adder, the mechanical transfer function unit, the detection mode differential capacitance detection unit, the second adder, the detection mode circuit gain module, the multiplier, and the tuning channel controller are connected in sequence. The detection mode closed-loop controller is connected between the output end of the detection mode circuit gain module and the first adder. The tuning channel circuit gain module is connected between the tuning channel controller and the third adder. The third adder is connected to the mechanical transfer function unit. The structure has the advantages of simple circuit structure, high precision, strong anti-interference capability, and high reliability.

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 present invention discloses a glass lifting system and method based on a touch pressure-sensitive key, comprising: a pressure-sensitive sensor, which receives key displacement and outputs a differential capacitance; a conversion circuit, which is electrically connected to the pressure-sensitive sensor, and receives the differential capacitance and converts it into an initial voltage; a central controller, which is electrically connected to the conversion circuit, and receives the initial voltage and outputs an adjustment frequency based on the initial voltage; a pulse modulation circuit, which is electrically connected to the central controller and receives the adjustment frequency, and outputs a modulation voltage based on the adjustment frequency; and a motor, which is electrically connected to the pulse modulation circuit and receives the modulation voltage, and the modulation voltage is used to adjust the motor speed and rotation direction.

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.