Sensitive structure of electrostatic negative stiffness resonant accelerometer and application method thereof

Abstract

The invention discloses a sensitive structure of an electrostatic negative stiffness resonant accelerometer and an application method thereof. The sensitive structure of the electrostatic negative stiffness resonant accelerometer comprises a first mass and a second mass which are arranged adjacent to each other, a first electrostatic driving portion, a first detecting portion, a first sensitive portion, a second electrostatic driving portion, a second detecting portion, a second sensitive portion, first to eighth fixed bases, first to eighth elastic connecting beams and mass elastic connectors. The application method comprises the following steps: firstly, driving the two masses to a driving mode; applying an initial voltage on the sensitive portion, the sensitive portion generating an electrostatic force, and calculating an initial electrostatic stiffness; and at this time, d1, d2 have changed relative to the starting positions, the positions of the masses change when an accelerationis applied to the masses, causing d1, d2 to change again, which leads to changes of the electrostatic stiffness and the resonance frequency, so that the purpose of adopting the resonant frequency to sensitive the acceleration is achieved.

Description

technical field [0001] The invention belongs to the technical field of inertial sensors, and in particular relates to a sensitive structure of an electrostatic negative stiffness resonant accelerometer and a using method thereof. Background technique [0002] Silicon micro-resonant accelerometer is a new type of micro-inertial device based on MEMS technology. Its basic working principle is to use the force-frequency characteristics of the vibrating beam to obtain the input acceleration by detecting the change of the resonant frequency. The basic mechanism of the silicon microresonant accelerometer consists of a sensitive mass and two resonators symmetrically distributed. When an external acceleration acts on the accelerometer, the inertial force on the sensitive mass will act on the two resonators. When one of the resonators is tensioned, the resonant frequency increases; while the other resonator is compressed, the resonant frequency decreases. The difference between the t...

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Problems solved by technology

[0003] At present, most of the research on silicon microresonant accelerometers is sensitive to acceleration through the force-frequency characteristics of the resonant beam. Acceleration is added to the resonant beam in the form of inertial force, causing the resonant frequency of the resonant beam to change, but at the same time it brings temperature. The frequency of the resonant beam has a great influence. When the accelerometer is first powered on, the temperature changes relatively large, and the change of temperature will also affect the change of the resonant frequency, which leads to the temperature performance of the accelerometer is not good enough.

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