21 results about "Capacitive accelerometer" patented technology

The utility model discloses a non-linear test tool for an MEMS capacitive accelerometer, relates to the technical field of accelerometer test, and aims to provide a non-linear test tool which is simple in structure, low in cost and capable of measuring triaxial acceleration of an accelerometer, and comprises a rotary table and a bearing piece, the bearing piece comprises a transverse bearing table and a longitudinal bearing table, the accelerometers can be installed on the transverse bearing table and the longitudinal bearing table, the surface normal of the surface, used for installing the accelerometers, of the longitudinal bearing table is in the same direction as the radial direction of the rotary table, when the rotary table rotates, the accelerometers can measure the centripetal acceleration at the moment, and the accelerometers are installed on the transverse bearing table and the longitudinal bearing table respectively. And the acceleration values of the accelerometer in three axial directions are measured respectively.

The application discloses a high-precision capacitive acceleration sensor based on a high-order non-Hermite circuit and belongs to the technical field of electronic sensors. The high-precision capacitive acceleration sensor comprises a capacitive accelerometer CO, a high-speed same-direction amplifier LM6171 and passive elements, the passive elements comprise a left LC resonator and a right LC resonator, the capacitive accelerometer is connected between the left LC resonator and the right LC resonator, the left LC resonator and the right LC resonator are respectively connected with a positive resistor R, a voltage source V g , a voltage source internal resistance Z0, a resistor R0 and a resistor R f containing an equivalent circuit of the high-speed same-direction amplifier LM6171 in parallel. The high-precision capacitive acceleration sensor based on the high-order non-Hermite circuit has the advantages of high sensing precision, strong structural stability, simple manufacturing process, low cost, good comprehensive performance, fast response, high sensitivity and suitability for actual use. Moreover, the non-Hermite circuit has the advantages of high efficiency, high flexibility, high degree of freedom, high adjustability, high circuit resonance frequency shift and high sensitivity.

The application belongs to the technical field of sensors, and particularly relates to a TSV-based MEMS capacitive accelerometer wafer-level packaging structure and a packaging method. The technology of gold-silicon bonding combined with TSV is adopted, the gold layer is used as a bonding medium and a sensor capacitor plate, the integrated problem of the plate structure and signal extraction in the MEMS sensor is solved, the design of a separate electrode layer or an additional plate in the traditional packaging is avoided, and the complexity of the packaging is reduced. Meanwhile, the gold layer has low resistance and good electrical conductivity, compared with the traditional electrode material, the signal can be better transmitted, and the electrical performance of the MEMS sensor is improved. After the TSV technology is combined, short-path signal extraction can be realized in the wafer, signal attenuation and interference are reduced, and signal integrity and precision are improved.

The application provides a capacitive MEMS accelerometer, which comprises: a MEMS device comprising a first differential capacitor, a first pad, a second differential capacitor, a second pad, a second end of the first differential capacitor and a second end of the second differential capacitor being coupled to a first node to which a first alternating current signal is applied; a processing circuit comprising a third pad, a third pad isolation component, a fourth pad, a fourth pad isolation component, a first compensation capacitor coupled to the third pad, a second compensation capacitor coupled to the fourth pad, a detection circuit coupled to the third pad and the fourth pad, wherein the first pad is coupled to the third pad, the second pad is coupled to the fourth pad, the second end of the third pad isolation component, the second end of the fourth pad isolation component, the second end of the first compensation capacitor and the second end of the second compensation capacitor are coupled to a second node to which a second alternating current signal is applied, the second alternating current signal being the same frequency and opposite phase to the first alternating current signal. In this way, the parasitic capacitance of the input end of the detection circuit is reduced, thereby improving the sensitivity of the accelerometer.

The utility model relates to the technical field of accelerometers, and discloses a triaxial capacitive accelerometer, which comprises an anchor point, and further comprises a first acceleration detection assembly, a second acceleration detection assembly, a third acceleration detection assembly, a fourth acceleration detection assembly, a fifth acceleration detection assembly and a sixth acceleration detection assembly which are sequentially arranged from outside to inside, the second acceleration detection assembly comprises a second mass block and a second detection electrode, and the second mass block and the first mass block are elastically connected in the second direction; the third acceleration detection assembly comprises a third mass block and a third detection electrode, the third mass block and the second mass block are elastically connected in the third direction, and the third detection electrode is a third direction differential capacitor. The triaxial capacitive accelerometer disclosed by the utility model has the advantages of simple structure and few anchor points, is suitable for an application scene of long-time stable work, prolongs the service life of the accelerometer, and improves the reliability of the accelerometer.

The invention discloses a three-axis capacitive accelerometer based on a staggered double-seesaw structure, and belongs to the field of micro-electro-mechanical systems. The accelerometer is structurally characterized by comprising a mass block (1), a snakelike elastic beam (2), a movable comb tooth electrode (3) and a fixed comb tooth electrode (4) which are used for detecting the acceleration of an X axis, a movable comb tooth electrode (5) and a fixed comb tooth electrode (6) which are used for detecting the acceleration of a Y axis, a movable comb tooth electrode (7) and a fixed comb tooth electrode (8) which are used for detecting the acceleration of a Z axis, a staggered double-seesaw (9) and a torsion beam (10). And the staggered double-seesaw (9) drives the movable comb-tooth electrode (7) to generate angular displacement relative to the fixed comb-tooth electrode (8) under Z-axis acceleration, so that the opposite area and capacitance between the movable comb-tooth electrode (7) and the fixed comb-tooth electrode (8) are changed. And the high-sensitivity detection of the Z-axis acceleration is realized by detecting the change of the capacitance. According to the staggered double-seesaw (9) structure, the symmetry of the mass block (1) is improved, and the interference of cross shafts is reduced.

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 invention discloses a capacitance accelerometer structure resistance error compensation method based on alternating constant current driving, which is characterized in that the separation of a structure capacitance component and a structure resistance component is realized through a capacitance accelerometer compensation circuit. The system establishes a reference channel and a detection channel under the excitation of a constant current source, the detection channel outputs a comprehensive response containing capacitance and resistance, two paths of signals are input into a digital processing unit through a compensation circuit and an analog-to-digital conversion module, and in-phase and orthogonal components are obtained through orthogonal demodulation. Through channel cooperative processing, capacitive components (real acceleration signals) and resistive components (loss and error sources) can be effectively distinguished, and errors introduced by the resistive components are filtered out. According to the method, the influence of resistance components on the capacitance detection precision is avoided, and high-precision capture of micro capacitance change is realized under a fixed amplitude condition, so that the sensitivity, the stability and the signal-to-noise ratio of the capacitance accelerometer are remarkably improved.

A method, system and sensor apparatus for estimating RPM of rotating machinery, can involve acquiring vibration data from an accelerometer sensor mounted on the rotating machinery and detecting vibration signals from the acquired vibration data. A Fast Fourier Transform (FFT) can be performed on the detected vibration signals for conversion of the detected vibration signals from a time domain to a frequency domain. An RPM of the rotating machinery can be estimated from the frequency domain, and fault frequences can be calculated using the estimated RPM and a bearing configuration provided by a user. A health diagnosis of the rotating machinery can be based on the calculated fault frequencies and an analysis of the detected vibration signals. In an embodiment, accelerometer sensor can be implemented as a MEMS capacitive accelerometer sensor.

The invention relates to the technical field of deep learning, and discloses a method and system for realizing sensitivity analysis of a capacitive accelerometer based on deep learning, and the method comprises the steps: calculating the capacitance sensitivity of the capacitive accelerometer; calculating an equivalent stiffness coefficient corresponding to a U-shaped beam in the capacitive accelerometer and the mass of an inertial component so as to calculate a capacitance inherent frequency corresponding to the capacitive accelerometer; outputting a high-dimensional representation feature corresponding to the capacitive accelerometer; calculating the prediction sensitivity corresponding to the capacitive accelerometer by using a sensitivity regression layer in the optimization analysis network; and calculating a difference degree between the prediction sensitivity and the capacitance sensitivity, and when the difference degree is greater than a preset difference degree, performing sensitivity analysis on the capacitive accelerometer to obtain an analysis result. The accuracy of sensitivity analysis of the capacitive accelerometer can be improved.

The application discloses a MEMS capacitive accelerometer, which comprises a cover plate, a structure layer and a substrate, the structure layer comprises a fixed frame and a mass block, an acceleration release groove one is arranged in the middle of the fixed frame, the mass block can be displaced along the X axis and the Y axis in the acceleration release groove one, the fixed frame is arranged between the cover plate and the substrate through four-edge clamping packaging, the mass block comprises a detection unit one, a detection unit two, a detection unit three and a detection unit four which are arranged in sequence in a counterclockwise method from the left lower corner and correspond to four corners, the detection unit one and the detection unit two and the detection unit three and the detection unit four are respectively symmetrically arranged along the Y axis to form an X axis acceleration detection differential structure, and the detection unit one and the detection unit four and the detection unit two and the detection unit three are respectively symmetrically arranged along the X axis to form a Y axis acceleration detection differential structure. The application designs a differential fixed-tooth bias detection structure, improves linearity and sensitivity, eliminates interference caused by a non-sensitive axis and reduces cross-coupling degree.

The application relates to the technical field of micro-electro-mechanical system accelerometers. In particular, the application relates to a structure and a preparation method of a dual-axis capacitive accelerometer chip. The structure of the chip comprises a substrate layer and a sensitive structure layer which are arranged in a stack; the sensitive structure layer comprises a main beam, a sensitive mass block and a plurality of movable electrodes located around the sensitive mass block; the sensitive mass block is arranged around the main beam, the side of the main beam is provided with an L-shaped folding beam which elastically connects the sensitive mass block; the movable electrodes are fixedly connected with the sensitive mass block; the movable electrodes and fixed electrodes located around the sensitive mass block form a differential capacitor structure; wherein the projection of the main beam on the substrate layer is a right-angle cross shape; the center of the cross of the main beam is fixedly connected with the substrate layer through a center anchor point, and the four square ends are respectively fixedly connected with the substrate layer through side end anchor points. The structure can reduce the problems of sensitivity reduction and mutual interference of dual-axis detection, and the problems of easy deformation and failure of the elastic structure.

The invention belongs to the technical field of MEMS capacitance accelerometers, and discloses a time division multiplexing charge balance bridge type capacitance readout circuit for suppressing parasitic capacitance, which comprises a front-end detection unit, a sampling and holding module and a fully differential amplification module which are connected in sequence, the front-end detection unit comprises a feedback driving module, a parasitic capacitance counteracting module and a level shifting module; the input end of the feedback driving module and the input end of the parasitic capacitance counteracting module are both externally connected with the output end of the MEMS capacitive accelerometer; the input end of the parasitic capacitance counteracting module is connected between one output end of the MEMS capacitive accelerometer and one input end of the feedback driving module; the output end of the feedback driving module is electrically connected with the input end of the level shifting module; and the output end of the level shift module is electrically connected with the fully differential amplification module through the sampling and holding module.

The application discloses a kind of double-axis impact-resistant capacitive accelerometer sensors based on embedded prong stop and anti-collision platform, and it is related to micro-electro-mechanical system manufacturing technical field.The movable mass block, first structural unit, second structural unit and anti-overload fixed anchor point area are included, the movable mass block is the whole block structure, and the anti-overload fixed anchor point area is located between the first structural unit and the second structural unit.The movable mass block is divided into upper, middle and lower three parts according to the position of the first structural unit, the anti-overload fixed anchor point area and the second structural unit, and the upper and lower parts of the movable mass block are the same and symmetrical.The first structural unit and the second structural unit both include a plurality of drive comb tooth anchor point areas, and each drive comb tooth anchor point area is provided with an anti-collision area and a comb tooth connection area at the part connected with the movable mass block, and the comb tooth connection area forms a corresponding variable gap sensitive differential capacitor.The part connected with the movable mass block of the anti-overload fixed anchor point area forms a plurality of anti-biaxial overload embedded prong stop areas.

This application belongs to the field of inertial sensor technology, specifically disclosing a low-parasitic capacitance MEMS accelerometer and its fabrication method. This application utilizes a hollowed-out region formed on the back of the pickup electrode, directly opposite the substrate, reducing the facing area between the pickup electrode and the upper cover silicon substrate, thus lowering parasitic capacitance. Furthermore, a grounding plate is placed between the pickup electrodes, shielding the relative movement between the excitation electrode and the upper cover silicon substrate, further reducing the influence of parasitic capacitance between the excitation electrode and the silicon substrate. Through a thin-film support structure combined with plasma dry etching, a hollowed-out region is formed on the back of the MEMS accelerometer pickup electrode. This fabrication method is simple, applicable to various capacitive MEMS accelerometers or gravimeters, and has good compatibility and practicality.

The invention discloses a vehicle gauge-level triaxial MEMS capacitive accelerometer, which comprises a cap layer, a device layer and a substrate layer, and is characterized in that the device layer is arranged between the cap layer and the substrate layer; the device layer comprises a detection area used for arranging sensitive units and an outer frame surrounding the outer side of the sensitive area, a Z-axis sensitive unit, an X-axis sensitive unit and a Y-axis sensitive unit are arranged in the detection area, and the X-axis sensitive unit and the Y-axis sensitive unit are arranged side by side in the X-axis direction to form an X-Y detection unit; and the Z-axis sensing unit is arranged on one side of the X-Y detection unit along the Y-axis direction. In the Z-axis sensing unit, a mass imbalance structure is realized by etching a groove in a single-side mass block, and a traditional unequal-length mass block scheme is replaced. According to the design, the effective mass is locally reduced, so that the torsion beam generates controllable torsion displacement under the action of external acceleration, and meanwhile, the initial capacitance difference caused by asymmetric structures is avoided.

The invention relates to a high-sensitivity MEMS capacitive accelerometer based on a novel folding beam structure and a preparation method thereof, and relates to the technical field of MEMS capacitive accelerometers, and the accelerometer comprises an upper cover which is provided with an upper fixed capacitor plate; a lower fixed capacitor plate is arranged on the lower cover; the sensitive silicon structure is arranged between the upper fixed capacitance plate and the lower fixed capacitance plate and comprises a fixed frame, a sensitive mass block located in the middle of the fixed frame and a folding beam used for connecting the sensitive mass block and the matching beam, and the folding beam is a snake-shaped beam and is of a variable cross-section structure; the width of the section is gradually reduced from the end connected with the matching beam to the end connected with the sensitive mass block. By adopting the variable cross-section snake-shaped beam structure, the wide part of the connecting end can bear large acceleration, and the structural stability is guaranteed; the rigidity of the narrower end is low, the sensitive mass block is easier to displace under the action of external acceleration, the capacitance change is more obvious, the detection sensitivity is improved, and the two aspects of requirements are considered.

The invention provides an acceleration sensor structure and an acceleration measuring method.The acceleration sensor structure comprises a first inductance coil structure and a second inductance coil structure, the first inductance coil structure is located on the surface of a movable mass block, and the second inductance coil structure is located on the surface of a second substrate; the vertical projection of the second inductance coil structure is at least partially overlapped with the first inductance coil structure, so that the acceleration sensor can obtain the acceleration value of the acceleration sensor through the change of the mutual inductance coefficient between the two inductance coil structures in a high-temperature environment. Furthermore, a movable electrode positioned on the side wall surface of the movable mass block is inserted between two adjacent fixed electrodes positioned on the side wall surface of the fixed mass block, so that the adjacent movable electrodes and the fixed electrodes on the two sides form a capacitive accelerometer structure. The displacement direction of the acceleration sensor in a high-temperature environment and the acceleration of the acceleration sensor at normal temperature can be obtained according to the capacitance change between the movable electrode and the fixed electrode.

This application discloses a real-time self-testing method and system for a capacitive accelerometer, relating to the field of accelerometers. The method includes: applying a fixed-phase excitation signal to an upper fixed electrode; applying an excitation signal that switches back and forth between a first phase state and a second phase state to a lower fixed electrode; wherein, in the first phase state, the excitation signal of the lower fixed electrode is in phase with the excitation signal of the upper fixed electrode, and in the second phase state, the excitation signal of the lower fixed electrode is out of phase with the excitation signal of the upper fixed electrode; in the first phase state, acquiring a first current signal output by a movable sensitive mass; in the second phase state, acquiring a second current signal output by the movable sensitive mass; and performing a self-test on the accelerometer based on the first and second current signals. Real-time self-testing of the accelerometer is achieved through phase transformation.

The utility model provides a comb tooth type capacitive acceleration sensor, which belongs to the technical field of acceleration sensors and comprises a substrate, a pole piece I, a pole piece II, a cantilever beam and a mass block. Cantilever beams are arranged at the two ends of the mass block, the two ends of the mass block are slidably connected with the corresponding cantilever beams in an inserted mode, and the two ends of the mass block are provided with abutting ends abutting against the corresponding cantilever beams. When the acceleration does not occur, the abutting ends at the two ends of the mass block abut against the corresponding cantilever beams at the same time. When acceleration occurs, the abutting end at one end of the mass block extrudes the corresponding cantilever beam and drives the cantilever beam to be bent, and the abutting end at the other end of the mass block is slidably separated from the corresponding cantilever beam, so that only the cantilever beam at one end is stressed and bent when the acceleration is generated, the number of the cantilever beams which are stressed and bent at the same time is reduced; and the sensitivity of the sensor is improved. Meanwhile, the cantilever beams at the two ends have a supporting effect on the mass block and are not completely separated, so that the stability of the direction of the mass block is ensured, and nonlinear errors are reduced.