Analysis and Design of a 3rd Order Velocity-Controlled Closed-Loop for MEMS Vibratory Gyroscopes

Sensors

Huan-ming Wu¹  Hai-gang Yang¹  Tao Yin¹ 

[1] Institute of Electronics, Chinese Academy of Sciences, Beijing 100190, China; E-Mails:

关键词: MEMS vibratory gyroscopes;    velocity-controlled closed-loop;    3rd order;    linear model;    optimization methodology;   

DOI  :  10.3390/s130912564

来源: mdpi

【 摘 要 】

The time-average method currently available is limited to analyzing the specific performance of the automatic gain control-proportional and integral (AGC-PI) based velocity-controlled closed-loop in a micro-electro-mechanical systems (MEMS) vibratory gyroscope, since it is hard to solve nonlinear functions in the time domain when the control loop reaches to 3rd order. In this paper, we propose a linearization design approach to overcome this limitation by establishing a 3rd order linear model of the control loop and transferring the analysis to the frequency domain. Order reduction is applied on the built linear model's transfer function by constructing a zero-pole doublet, and therefore mathematical expression of each control loop's performance specification is obtained. Then an optimization methodology is summarized, which reveals that a robust, stable and swift control loop can be achieved by carefully selecting the system parameters following a priority order. Closed-loop drive circuits are designed and implemented using 0.35 μm complementary metal oxide semiconductor (CMOS) process, and experiments carried out on a gyroscope prototype verify the optimization methodology that an optimized stability of the control loop can be achieved by constructing the zero-pole doublet, and disturbance rejection capability (D.R.C) of the control loop can be improved by increasing the integral term.

【 授权许可】

CC BY   
© 2013 by the authors; licensee MDPI, Basel, Switzerland.