Closed-loop control type accelerometer

Abstract

The invention discloses a closed-loop control type accelerometer. The closed-loop control type accelerometer comprises a quartz vibrating-beam acceleration sensitive element and an actuator. The surface of a mass block of the quartz vibrating-beam acceleration sensitive element is opposite to the actuator and provided with an actuating electrode couple. The actuating electrode couple is used for changing the position of the mass block through adjusting the voltage which is applied between the actuating electrode couple. The actuator comprises a clamping beam, a board-shaped block, a supporting beam which connects the clamping beam and the board-shaped block, and an actuating electrode which is coated on the board-shaped block to produce actuating acting force. When acceleration is input, the mass block deviates from an equilibrium position and cause a change of vibrating frequency of a vibrating beam, the change is detected and the voltage between the corresponding actuating electrode couple is adjusted , and the mass block is enabled to go back to the equilibrium position again. The closed-loop control type accelerometer achieves closed-loop control of the accelerometer, improves measuring range and linearity and meanwhile keeps the detection accuracy of the accelerometer, and overcomes the disadvantage that the linearity and the range is reduced because of the improving of sensitivity of a quartz vibrating-beam accelerometer.

Description

technical field [0001] The invention relates to the fields of resonance frequency identification and closed-loop controllable acceleration detection, in particular to a closed-loop control accelerometer. Background technique [0002] With the maturity of navigation algorithms and navigation computers, the accuracy of inertial navigation systems such as navigation and guidance is increasingly restricted by the performance of accelerometers and gyroscopes. Quartz vibrating beam accelerometer is a commonly used high-precision accelerometer at present. It uses the change of resonant frequency when the vibrating beam is subjected to axial stress to detect the input acceleration. [0003] At present, the quartz vibration beam accelerometer has two structures: double vibration beam and single vibration beam, and the representative companies are Honeywell in the United States and Onera in France. Honeywell uses a double beam structure, and other auxiliary structures such as vibrati...

AI Technical Summary

Problems solved by technology

[0004] However, due to the flexible structure of the quartz beam accelerometer of Onera, France, in order to obtain higher sensitivity, the sensor can only maintain excellent linearity in a small range, and the range and sensitivity have become performance parameters that restrict each other.

In the existing quartz beam accelerometer structure, the sensitivity is often increased by increasing the quality of the mass block or reducing the bending stiffness of the vibration beam and the flexible bridge, resulting in a decrease in the linearity and range of the sensor; and in order to obtain a larger The measurement range needs to be realized by reducing the mass of the mass block or increasing the bending stiffness of the vibrating beam and the flexible beam, which objectively sacrifices the sensitivity performance

[0005] In order to eliminate the above disadvantages, on the basis of the existing vibrating beam structure, France Onera proposed a new vibrating beam structure with a narrow middle and wide ends, which improved the sensitivity slightly without changing the bending stiffness of the flexible beam, but this This new structure has a very limited improvement in sensitivity, and puts forward higher requirements for the manufacturing process of the device, which makes the manufacturing of the device more difficult, and may lead to a decrease in the yield of the device.

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