电容式微机械陀螺双环路闭环驱动电路研究

为了提高微机械陀螺系统的检测灵敏度,对微机械陀螺系统的驱动电路进行了研究.分析了微陀螺闭环驱动系统理论,基于此提出一种双环路闭环驱动方法,并且利用数学工具simulink建立系统模型,验证此方法的可行性,最后设计完成相应电路.此方法引入锁相环实现闭环驱动电路的稳频控制;采用自动增益控制器(AGC)实现恒幅控制.利用Hspice完成电路级仿真.结果表明,微机械陀螺双环路闭环驱动电路建立稳定振荡的时间为45 ms,稳定振荡频率为2.7553 KHz,频率偏差为0.1 z,频率抖动为0.056563 Hz.相对于传统的AGC闭环驱动电路,此闭环驱动电路建立稳定振荡时间缩短了30.77%,频率稳定性是传统AGC闭环驱动电路的32.72%.微机械陀螺环路闭环驱动电路提高驱动信号性能,对于微机械陀螺检测灵敏度的提高有着重要意义.

The Research on the Dual Closed-Loop Driving Circuits for Micro-machined Gyroscope

In order to improvement the detection sensitivity for micro-machined gyroscope,Studying on the driving circuits of the micro-machined gyroscope the dual closed-loop driving scheme for micro-machined gyroscope is proposed based on the analysis of the phase theory and amplitude theory, and the scheme is verified using simulink model. the related circuits have also been implemented. Considering the characteristics of Phase-Locked Loop (PLL), PLL is applied to adjust the frequency of driving signal in accordance with the resonant frequency in the driving mode; the amplitude control includes peak detector, DC comparator and Variable Gain Amplifier (VGA) to achieve the constant amplitude. The simulation results show that, setting time of stable oscillation is at 45ms and the stable oscillation frequency is 2.7553 KHz. The frequency difference between driving frequency and resonant frequency is only 0.1Hz. Frequency jitter is 0.056563Hz. Compared with the traditional closed-loop driving circuits, setting time of the dual closed-loop driving circuits shorten 30.77%. The frequency jitter is 32.72% of the AGC closed-loop driving circuits for micro-machined gyroscope the dual closed-loop driving circuits for micro-machined gyroscope improved the quality of the driving signal So it is significative for the improvement of the detection sensitivity for micro-machined gyroscope.