摘要
传统MEMS(Micro-Electro-Mechanical System)陀螺的相干检测基于驱动位移和科氏位移的相位关系,依赖于陀螺的工作模式,解调载波相位抖动大,不易相位对准.为解决此问题,本文提出了一种基于正交误差对准的不依赖陀螺工作模式的相干解调系统.解调载波取自驱动电路的PLL(Phase-Locked Loop)输出,相位抖动小,仅作载波使用,不代表驱动位移信息.检测通路插入移相器,使正交误差相位滞后解调载波90°,则科氏位移信号与解调载波同相,完成检测.为验证该方法,本文研究了陀螺器件与接口电路之间的信号传递特性并进行建模,设计了锁相环、C/V(Capacitance/Voltage)转换、移相器等核心电路,实现了一款完整的MEMS陀螺测控电路.测试结果表明:陀螺驱动正常,检测正确,刻度因数为1.415mV/(°.s),零偏不稳定度为108°/h.结果验证了该检测方法的有效性,并为后续进一步提升性能提供了基础.该检测方法也适用于其他振动式MEMS陀螺的测控系统.
Traditional synchronous demodulation of MEMS （Micro-Electro-Mechanical System） gyroscope is based on phase relationship of drive and sense positions. This relationship depends on the work mode of gyro. Moreover, the phase jitter of drive displacement is large, which makes the phase alignment of demodulator hard. To solve these problems,a new demodulation method based on quadrature error alignment was proposed, which is independent on work mode of gyro. Demodulator reference was extracted from PLL （Phase-locked loop） output,which has low jitter. Phase shifter of sense channel was used to delay quadrature error by 90°, compared with the reference signal. Therefore, Coriolis signal and the reference were automatically in-phase,and successful demodulation was achieved. To demonstrate this method, drive mode and sense-mode circuits were elaborately implemented, and several critical blocks were care fully de signed. The demodulation of MEMS gyro shows that the vibration oscillation is stable and the operation of sense channel is correct. The scale factor is 1.415 mV/（°· s） ,and the bias instability is 108°/h. Moreover, the measurement results verify the validity of the demodulation method, providing solid foundation for fur ther research. The method is also applicable to other vibratory MEMS gyroscopes.
出处
《湖南大学学报（自然科学版）》
EI
CAS
CSCD
北大核心
2017年第10期109-116,共8页
Journal of Hunan University:Natural Sciences
基金
国家自然科学基金资助项目(61501453)~~
关键词
相干检测
正交误差
读出系统
陀螺
MEMS传感器
coherent demodulation
quadrature error
readout systems
gyroseopes
MEMS sensors
作者简介
陈华（1984-），男，湖北浠水人，中科院微电子所博士研究生.
通信联系人，E-mail；guoguiliang@ime．ac．cn
