基于数字锁相环控制的硅微陀螺仪驱动模态分析与实验

Analysis and experiment of drive mode of silicon micro-gyroscope based on digital phased-locked loop control

为了有效控制硅微陀螺仪的驱动模态,采用基于数字锁相环的相位控制方案对驱动信号振动频率进行跟踪控制.首先,分析了硅微陀螺仪驱动模态的特点,提出了一种数字锁相环控制驱动信号频率的方法;其次,阐述了基于锁相环的硅微陀螺仪驱动模态闭环控制原理,并分析了锁相环频率控制的稳定性;然后,对锁相环控制的驱动模态频率变化和跟踪情况进行了仿真,验证了驱动频率动态跟踪特性;最后,设计了一种基于锁相环的FPGA数字电路控制方案,并制作成实际电路,同时,对硅微陀螺仪驱动模态的开环谐振频率驱动和闭环频率驱动进行了对比实验.结果表明,当温度在-40～60℃内变化时,该控制方案能够保证驱动频率时刻跟踪驱动模态谐振频率的变化,且跟踪相对误差为2.5×10-5.

In order to control the drive mode of a silicon micro-gyroscope effectively,a phase control scheme based on the digital phase-locked loop（PLL） control is put forw ard to trace and control the vibration frequency of the drive signal.First,the drive mode characteristics of the silicon microgyroscope are analyzed,and a digital PLL method for controlling the frequency of the drive signal is proposed.Secondly,the theory of the silicon micro-gyroscope closed-loop control based on the PLL is elaborated,and the stability of the PLL frequency control is analyzed.Then,the frequency changing and tracing characteristics based on PLL control in the drive mode are simulated,and the drive frequency dynamic tracing characteristic are verified.Finally,a digital circuit scheme w ith field programming gate array（FPGA） based on the PLL control is designed and the real circuit is manufactured.Besides,the open loop resonant frequency and the closed loop tracing frequency to drive the silicon micro-gyroscope are compared by experiments.The results demonstrate that w hen the temperature is betw een-40 and 60 ℃,the proposed control scheme can ensure that the drive frequency traces the resonant frequency change constantly,and the relative error is 2.5 × 10^-5.