基于FPGA的硅微机械谐振式陀螺仪数据采集系统设计

Design of Data Acquisition System for Micromachined Silicon Resonant Gyroscope Based on FPGA

介绍了一种硅微机械谐振式陀螺仪的结构,给出了调制系数或最大频偏与输入角速度成正比的关系.通过对陀螺仪敏感质量块静电驱动力和双端音叉谐振器输出信号的分析,得出了双端音叉谐振器输出信号的相位差与调制系数之间的关系.提出了一种调频信号最大频偏的检测方法,通过此相位差的计算得出调制系数或最大频差,进而计算出输入角速度的值.设计了一种基于FPGA的数字化解调方案,给出了基于FPGA的数字化最大频差测量电路的测试结果.结果表明测量电路对最大频偏有很好的测量效果.

The structure of the micromachined silicon resonant gyroscope was introduced and the relationship between the maximum frequency shift or modulation index and input angular velocity signal was presented.According to the analysis of the electrostatic comb-finger driving-force of the sensitive proof mass and the output signal of double-ended tuning fork（DETF） resonator,the relationship between phase difference of output signal of DETF and modulation index was obtained.A detection method for maximum frequency shift was proposed,in which phase difference was calculated for computation of modulation index or the maximum frequency shift so that the input angular velocity could be obtained.Based on this method,a digital demodulation scheme using field programmable gate array（FPGA） was designed and experiments were carried out on the maximum frequency shift detecting circuit based on FPGA.The experimental results show that the circuit is feasible to measure the maximum frequency shift and has excellent measurement effect.