Search

CN-119619549-B - Micromechanical accelerometer

CN119619549BCN 119619549 BCN119619549 BCN 119619549BCN-119619549-B

Abstract

The invention provides a micromechanical accelerometer, which comprises at least four fixed anchor points, an inertial mass module, a plurality of elastic connection modules and a plurality of detection capacitor modules, wherein the fixed anchor points are integrally formed into a rectangle and are positioned at four vertexes of the rectangle, the inertial mass module is positioned in the middle of the rectangle and is respectively connected with all the fixed anchor points, the elastic connection modules are respectively connected between the inertial mass module and the fixed anchor points, the detection capacitor modules are arranged on the inertial mass module and are used for detecting displacement of the inertial mass module, two fixed anchor points positioned on the same side are connected with positive voltages, two fixed anchor points positioned on the other side are connected with negative voltages, or one group of fixed anchor points positioned on a diagonal position are connected with positive voltages, the other group of fixed anchor points positioned on the diagonal position are connected with negative voltages, the positive voltages and the negative voltages are equal in amplitude, and the fixed anchor points, the elastic connection modules and the inertial mass module form a passage. The invention has compact structure and can obviously improve the sensitivity of the capacitive micromechanical accelerometer.

Inventors

  • WU TAO
  • Xiong Ruihong

Assignees

  • 上海科技大学

Dates

Publication Date
20260508
Application Date
20241203

Claims (5)

  1. 1. A micro-mechanical accelerometer, comprising a micro-mechanical accelerometer, characterized by comprising the following steps: at least four fixed anchor points, wherein the fixed anchor points integrally form a rectangle and are positioned at four vertexes of the rectangle; the inertial mass module is positioned in the middle of the rectangle and is respectively connected with all the fixed anchor points; The elastic connection modules are respectively connected between the inertial mass module and the fixed anchor point, and comprise: one end of the linear folding beam is connected to the inertial mass module, and the other end of the linear folding beam is connected to the fixed anchor point; the device comprises two straight beams and a semicircular beam, wherein one straight beam is connected between one end of the semicircular beam and the inertial mass module, and the other straight beam is connected between the other end of the semicircular beam and the fixed anchor point; a nonlinear curved beam with one end connected to the inertial mass module and the other end connected to the fixed anchor point, the nonlinear curved beam having a fixed width and a side shape satisfying a cosine function curve shape, and The detection capacitor modules are arranged on the inertial mass modules and are used for detecting displacement of the inertial mass modules; the displacement direction of the inertial mass module is set to be a first direction, the surface of the inertial mass module is set to be a second direction perpendicular to the first direction, and a plurality of detection capacitor modules are arranged on the inertial mass module along the second direction; Along the second direction, two fixed anchors positioned on the same side are connected with a positive voltage, two fixed anchors positioned on the other side are connected with a negative voltage, or one group of fixed anchors positioned on a diagonal position are connected with a positive voltage, the other group of fixed anchors positioned on the diagonal position are connected with a negative voltage, and the magnitudes of the positive voltage and the negative voltage are equal; The fixed anchor point, the elastic connection module and the inertial mass module form a passage, after being electrified and heated, the linear folding beam generates a positive stiffness coefficient, the nonlinear bending beam generates a negative stiffness coefficient, and an equivalent stiffness coefficient formed by overlapping the positive stiffness coefficient and the negative stiffness coefficient is zero; the micromechanical accelerometer further comprises a plurality of feedback capacitance modules, and the feedback capacitance modules are arranged on the inertial mass module along the first direction; a plurality of detection anchor points arranged on two sides of the inertial mass module along the second direction, and The feedback anchor points are arranged on two sides of the inertial mass module along the first direction.
  2. 2. The micromechanical accelerometer of claim 1, wherein the detection capacitance module comprises: A movable detection comb connected to the inertial mass module, and The fixed detection comb teeth are connected to the detection anchor points; The movable detection comb teeth and the fixed detection comb teeth form a detection capacitor correspondingly, and the capacitance change value of the detection capacitor corresponds to the displacement of the inertial mass module.
  3. 3. The micromechanical accelerometer of claim 2, wherein the movable detection comb and the fixed detection comb each comprise a plurality of comb cantilevers, each comb cantilever having a comb array thereon, the plurality of comb cantilevers of the movable detection comb and the plurality of comb cantilevers of the fixed detection comb forming a plurality of pairs of parallel plates.
  4. 4. The micromechanical accelerometer of claim 1, wherein a plurality of detection capacitance modules are symmetrically distributed about a centerline of the inertial mass module parallel to the first direction and symmetrically distributed about a centerline of the inertial mass module parallel to the second direction.
  5. 5. The micromechanical accelerometer of claim 1, wherein the elastic connection module has an equivalent stiffness coefficient of 0.1N/m or less after being electrically heated.

Description

Micromechanical accelerometer Technical Field The invention relates to the technical field of micro-electromechanical systems, in particular to a micro-mechanical accelerometer. Background As a typical inertial device in a microelectromechanical system (MEMS), a micromechanical accelerometer has a wide application prospect in various fields such as aerospace, automotive industry, consumer electronics, etc., due to its characteristics of small size, light weight, low cost, high reliability, and suitability for mass production. The high-resolution capacitive accelerometer is widely used in the high-precision measurement fields of inertial navigation, seismic detection and the like. The structural sensitivity of the micromechanical accelerometer is directly influenced by the stiffness coefficient of the elastic structure, and the lower the stiffness is, the higher the sensitivity is. In the prior art, the micro-mechanical anti-spring accelerometer biases the elastic structure at a low-stiffness position through the gravity of the inertial mass block, so that the quasi-zero stiffness coefficient is realized. However, such designs typically require large biasing forces and biasing displacements, resulting in such accelerometers that achieve a quasi-zero stiffness coefficient while being difficult to further miniaturize. Therefore, there is a need for improvement. Disclosure of Invention In view of the above-mentioned drawbacks of the prior art, an object of the present invention is to provide a micromechanical accelerometer, which is used for solving the technical problem that the micromechanical counter spring accelerometer in the prior art needs a large biasing force and a large biasing displacement, so that it is difficult to further miniaturize while achieving quasi-zero stiffness. To achieve the above and other related objects, the present invention provides a micromechanical accelerometer, comprising: at least four fixed anchor points, wherein the fixed anchor points integrally form a rectangle and are positioned at four vertexes of the rectangle; the inertial mass module is positioned in the middle of the rectangle and is respectively connected with all the fixed anchor points; A plurality of elastic connection modules respectively connected between the inertial mass module and the fixed anchor point, and The detection capacitor modules are arranged on the inertial mass modules and are used for detecting displacement of the inertial mass modules; the displacement direction of the inertial mass module is set to be a first direction, the surface of the inertial mass module is set to be a second direction perpendicular to the first direction, and a plurality of detection capacitor modules are arranged on the inertial mass module along the second direction; Along the second direction, two fixed anchors positioned on the same side are connected with a positive voltage, two fixed anchors positioned on the other side are connected with a negative voltage, or one group of fixed anchors positioned on a diagonal position are connected with a positive voltage, the other group of fixed anchors positioned on the diagonal position are connected with a negative voltage, and the magnitudes of the positive voltage and the negative voltage are equal; the fixed anchor point, the elastic connection module and the inertial mass module form a passage. In an embodiment of the invention, the elastic connection module includes: one end of the linear folding beam is connected to the inertial mass module, and the other end of the linear folding beam is connected to the fixed anchor point; the device comprises two straight beams and a semicircular beam, wherein one straight beam is connected between one end of the semicircular beam and the inertial mass module, and the other straight beam is connected between the other end of the semicircular beam and the fixed anchor point; And one end of the nonlinear curved beam is connected to the inertial mass module, and the other end of the nonlinear curved beam is connected to the fixed anchor point. In an embodiment of the present invention, the linear folding beam includes two straight beams and one semicircular beam, wherein one straight beam is connected between one end of the semicircular beam and the inertial mass module, and the other straight beam is connected between the other end of the semicircular beam and the fixed anchor point. In an embodiment of the present invention, the width of the nonlinear curved beam is a fixed value, and the shape of the side edge thereof satisfies the cosine function curve shape. In an embodiment of the invention, the micromechanical accelerometer further includes a plurality of feedback capacitance modules disposed on the inertial mass module along the first direction. In an embodiment of the invention, the micromechanical accelerometer further comprises: a plurality of detection anchor points arranged on two sides of the inertial mass module along t