Weakly Coupled Resonant Microaccelerometer with Adjustable Sensitivity

Abstract

A weakly coupled resonant micro accelerometer with adjustable sensitivity, comprising: a first mass structure, a second mass structure and a resonant structure, the resonant structure is respectively connected to the first mass structure and the second mass structure; the The resonant structure includes: a first sensitive resonator with the same voltage, a second sensitive resonator and a coupling resonator, and a sensitivity adjustment resonator. The first quality block structure includes: a first mass block, a first fixed anchor point and a first elastic beam; the second mass block structure includes: a second mass block, a second fixed anchor point and a second elastic beam. The present invention greatly improves the ultimate sensitivity of the accelerometer through the three-degree-of-freedom weak-coupling structure design and the modal localization principle of measuring the amplitude ratio, and additionally adds a resonator on the basis, by adjusting the resonator and the other two The sensitivity of the accelerometer is adjusted by the negative stiffness of the electrostatic coupling between the resonators, which expands the measuring range by more than 50 times, so that the present invention can be applied to the working scene with a large acceleration variation range.

Description

technical field [0001] The invention relates to a technology in the field of microelectromechanical systems (MEMS), in particular to a weakly coupled resonant micro accelerometer with adjustable sensitivity. Background technique [0002] In recent years, a new type of MEMS resonant accelerometer has been reported in foreign journals and domestic patents. It is based on the modal localization mechanism that won the Nobel Prize in Physics in 1977. By measuring two weakly coupled resonator The amplitude ratio of is used as output. Compared with the traditional frequency output resonant accelerometer, the sensitivity of the resonant accelerometer adopting the sensitive mechanism is improved by more than two orders of magnitude. However, the weakly coupled resonant accelerometer based on the mode localization mechanism still has many problems before it can be used in practice, the most prominent one of which is its limited range. When measuring a large acceleration, the amplitu...

AI Technical Summary

Problems solved by technology

When measuring a large acceleration, the amplitude difference between the two resonators is very large. When calculating the amplitude ratio, there will be a large number divided by a small number, resulting in a sharp increase in the error of the accelerometer output.

In the inertial navigation system, the range of acceleration changes is often very large, which leads to the inability of the accelerometer with this sensitive mechanism to take into account both high sensitivity and large range, which greatly limits its practical application.

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