Optical phase detecting high precision silicon microelectromechanical gyroscope

Abstract

The invention relates to a high precision silicon micro electronmechanical gyroscope of optical phase detection. Tail optical fiber of a light source and entering fiber of a photoelectric detector are respectively in heat sealing with one optical fiber of a Y-shaped optical coupler. A micro mirror is made on a vibration beam to be used for reflecting transmitted light passing through the tail optical fiber of the Y-shaped optical coupler. The photoelectric detector detects interference fringe formed by the confluence of the reflected light on the micromirror and the reflected light on the end face of the tail optical fiber of the Y-shaped optical coupler by the Y-shaped optical coupler. The photoelectric detector is connected with a detection and control system. The invention adopts optical interference principle and uses an optical phase measurement method to measure the infinitesimal displacement of a vibration mass block, thus improving the detection sensitivity and reading accuracy of the gyroscope. The gyroscope is characterized by small volume, light weight, high resolution, low drift, short response time and high reading accuracy, improves dynamic response range and detection accuracy, is beneficial to the implementation of digital filter and signal transmission processing simultaneously and improves the anti-interference capacity of the system.

Description

technical field [0001] The invention relates to a device for measuring rotational angular velocity, in particular to a high-precision silicon micro-electromechanical gyroscope using optical phase detection, which combines optical fiber Michelson interference technology on the basis of traditional silicon micro-electromechanical gyroscopes, and integrates optical and micro-electromechanical systems ( MEMS), precision machinery and electronic technology in one sensor, can upgrade the medium and low precision MEMS gyroscope to medium and high precision MEMS gyroscope. Background technique [0002] The principle of the gyroscope is: the direction pointed by the rotation axis of a rotating object will not change when it is not affected by external forces, and then read the direction indicated by the axis in a variety of ways, which is to maintain relative tracking in dynamic State of the precision angle, angular velocity sensor. Because the gyroscope can carry out independent me...

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Problems solved by technology

[0005] However, the capacitive detection method usually adopted by MEMS gyroscopes has a very small capacitance change of up to 10 -18 F, so the accuracy and sensitivity are difficult to improve, and the accuracy is far inferior to laser and fiber optic gyroscopes, so it can only be applied to low-end angle measurement systems

At the same time, due to the existence of parasitic capacitance, the noise of the output signal of the MEMS gyro is relatively large, and the drift stability is poor.

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