Weak coupling resonance type micro-accelerometer with adjustable sensitivity

Abstract

The invention relates to a weak coupling resonance type micro-accelerometer with adjustable sensitivity. The weak coupling resonance type micro-accelerometer comprises a first mass block structure, asecond mass block structure and a resonance structure. The resonance structure is connected with the first mass block structure and the second mass block structure. The resonance structure includes afirst sensitive resonator, a second sensitive resonator, a coupling resonator and a sensitivity adjusting resonator, wherein the first sensitive resonator, the second sensitive resonator, and the coupling resonator have the same voltages. The first mass 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. According to the invention, the limit sensitivity of the accelerometer is substantially improved through a three-degree-of-freedomweak coupling structure design and a modal localization principle for measuring an amplitude ratio; a resonator is additionally added based on the original design and the sensitivity of the accelerometer is adjusted by adjusting the electrostatic coupling negative stiffness between the resonator and the other two resonators, so that the measuring range is expanded by more than 50 times. Therefore,the weak coupling resonance type micro-accelerometer is suitable for a working scene with a very large acceleration change 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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