9 results about "Capacitive accelerometer" patented technology

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 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 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 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 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 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.