基于相位控制的硅微机械陀螺驱动控制技术

全面分析、研究并实现了一种基于相位控制的硅微机械陀螺(Silicon micromechanical gyroscope, SMG)驱动控制技术. 分析了硅微陀螺驱动模态的动力学特性,阐述了相位控制方案的基本原理; 在此基础上建立了控制环路,采用自激振荡理论分析了其稳定性; 建立了环路的相位模型,引入特异因子实现相位控制误差到频率差 (工作频率与驱动模态谐振频率之差)的转换; 建立了对应于相位控制环路的频率模型,当环路滤波器为一阶模型时, 与传递函数为二阶的信号跟踪锁相环(Phase locked loop, PLL)不同,总的闭环模型仅为一阶; 最后基于FPGA平台,采用线性鉴相方式设计了数字化相位控制环路, 并结合幅值控制实现了双闭环驱动控制电路.测试结果表明, 该方案可实现硅微陀螺驱动端的高精度控制.

A Drive Control Scheme Based on Phase-control for Silicon Micromechanical Gyroscopes

A drive control scheme based on phase-control for silicon micromechanical gyroscopes (SMG) is studied and implemented. By analyzing the dynamical characteristics of the drive mode, the elementary principle of phase control scheme upon which the control loop is built is described and the stability of the loop is presented using the theory of self-sustained oscillation. The phase model of the loop is modeled where a special factor is introduced to realize the conversion from phase-error to frequency-error which is the difference between current working frequency and the resonance-frequency of the drive mode. By building the frequency closed-loop corresponding to the phase-control loop, we find that the order of the loop-filter is just one when considering loop-filter as a first-order-model, which is different from the general phase locked loop (PLL) that is second-order. Elaborate design of the digital phase-control circuit is carried out based on the FPGA platform where a linear phase-detector is applied. Aided by an amplitude control loop, a double-closed-loop drive control circuit is realized. Results show that the drive control loops work precisely.