Accelerometer

Abstract

The invention discloses an accelerometer which comprises a substrate and an accelerometer body fixed to the substrate. The accelerometer body comprises a plurality of parallel-connection sensing units, wherein each sensing unit comprises a mass block, a first fixed base and a tooth set, two longitudinal ends of the mass blocks are fixedly connected with the substrate through elastic pieces, the elastic pieces are arranged at two longitudinal ends of the mass blocks, the first ends of the mass blocks are fixedly connected with the substrate, the first fixed bases are arranged on transverse side faces of the mass blocks and are fixedly connected with the substrate, the tooth sets are arranged between the first fixed bases and the mass blocks, and each tooth set comprises a plurality of fixed teeth which are fixed to the first fixed bases, extend in the transverse direction and are spaced from one another in the longitudinal direction, and a plurality of movable teeth which are staggered between the fixed teeth and fixed to the mass blocks. Through the parallel connection of the sensing units, the sensitivity and resolution are improved, and the nonlinearity of acceleration full range is improved through capacitance changes of a variable area.

Description

technical field [0001] The invention relates to the technical field of micromechanical inertial instruments, in particular to an accelerometer. Background technique [0002] High-range micromachined accelerometers are widely used in fields such as explosion and shock testing. In these applications, the magnitude of the instantaneous shock acceleration may exceed 100,000g, and the shock duration is very short (usually within a few hundred microseconds), so the accelerometer has a high range and resonant frequency. [0003] The capacitive silicon micromachined accelerometer has unique advantages such as mature technology, high frequency response, low power consumption, small temperature drift and strong overload resistance. It can meet the requirements of high range and high resonance frequency. Large high-g accelerometer type. [0004] At present, there are two main structural forms of capacitive high-range silicon micromachined accelerometers: the torsional structure of th...

AI Technical Summary

Problems solved by technology

However, these two accelerometers are out-of-plane sensitive forms with variable gaps, and their anti-overload capability cannot meet some special requirements.

[0005] Existing high-range micromachined accelerometers generally work in an open-loop state. When high-amplitude acceleration is input, the deformation of the sensor’s sensitive mass is large. The variable-gap capacitance sensing method of the above two accelerometers will cause the full-scale linearity to deteriorate.

Existing high-range micromachined accelerometers have low sensitivity due to limitations in range and resonant frequency

These problems have restricted the further improvement of the performance of capacitive high-range micro-machined accelerometers

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