硅微z轴谐振陀螺仪负电刚度效应分析及实验验证

The Negative Electrostatic Spring Effect Analysis and Experimental Validation of Silicon Micromechanical Vibrating z-axis Gyroscope

介绍了在开环工作状态下硅微z轴谐振陀螺仪由于加工工艺缺陷所导致的误差机理。为减小陀螺仪初始电容差和抑制正交耦合误差,提出了一种闭环控制检测策略。重点分析了其力矩反馈器的电刚度效应并给出其线性数学模型表示式。通过对硅微z轴陀螺仪敏感模态的反馈力与谐振频率的关系分析,间接得出了在敏感方向上电负刚度与力矩器所施电压的内在联系,并在实验上进一步验证电刚度效应。这将为下一步闭环控制方案的设计奠定重要基础。

The error principle caused by structural process imperfection of silicon micromechanical z-axis gyroscope in open mode is introduced firstly. A new closed-loop control detection strategy is presented, which would has advantage of minimizing the initial capacitance difference and restraining the cross-talk coupling errors. The negative electrostatic spring effect of feedback force generator is analyzed in focus, and its linear mathematics module is calculated out. By computing the relation between the resonant frequency and feedback force added on the sense mode of MEMS z-axis gyroscope, the inner relation between the negative electrostatic spring coefficient in sense axis and the voltage on the feedback force generator is deduced indirectly. The theory has been testified by experiment, which will lay foundation for the next design of closed-loop scheme.