基于FPGA的硅微机械陀螺特性曲线可重构测试

Reconfigurable testing system for silicon micromechanical gyroscope characteristic curve based on FPGA

设计了一套基于FPGA(Field Programmable Gate Array)的硅微机械陀螺特性曲线可重构测试系统,能够同时测试出硅微机械陀螺的驱动频率特性以及驱动模态到敏感模态的正交耦合特性。基于SOPC(System On a Programmable Chip)嵌入式软件编写程序,采用扫频方法从驱动激励端输入一系列由低频到高频的正弦激励信号,在驱动检测端输出,可以扫描出驱动模态的频率特性曲线,同时在敏感检测端输出,可以扫描出驱动模态到敏感模态的正交耦合特性曲线。根据驱动模态的频率特性曲线,能够测量出驱动模态在谐振频率点的相位特性(代表了整个环路的真实相移),据此能够使闭环控制回路精确工作在谐振频率点。此外,改变SOPC嵌入式软件程序,也可以直接实现闭环驱动控制与敏感解调输出,而不需要额外的硬件开销。

A reconfigurable testing system for silicon micromechanical gyroscope characteristic curve was designed based on FPGA（Field Programmable Gate Array） to test the drive frequency characteristic and the quadrature coupling characteristic from drive mode to sense mode. Based on SOPC（System on a Programmable Chip） embedded software, a series of sine actuating signals from low frequency to high frequency is inputted, which adopts frequency sweep method on drive excitation end. By processing output signal from drive mode detection capacitance and sense mode detection capacitance, the frequency characteristic curves of drive mode and quadrature coupling characteristic curve from drive mode to sense mode can be derived respectively. Based on the frequency characteristic curve of the drive mode, the phase characteristic about resonance frequency（that represents true phase shift of the whole loop ） of drive mode can be measured to precisely /]x the closed-loop drive circuit to resonance frequency. In addition, By improving the programme based on SOPC embedded software, the closed-loop drive control and sense demodulation output can be realized without extra hardware.