驱动方式对微流体陀螺仪输出信号的影响

Influence of drive modes on output signals of micro-fluidic gyroscope

研究了不同驱动方式下微流体陀螺仪敏感信号的检测方法及其特性。介绍了陀螺仪的工作原理,给出了两种驱动方式下的信号检测方案。直流电压驱动时,敏感到直流流速,经过差动电桥放大后,可得输出电压。交流电压驱动时,敏感到交流流速,用相干检测方法提取有用信号,通过低通滤波、放大,最终得到正比于外界输入角速度的直流电压。实验数据分析可得:交流电压驱动时,输出信号的标度因数为17.05μV/(°)s-1,标度因数非线性为5.725%,标度因数对称性为4.52%,零偏及零偏稳定性为1 066°/s和14.3°/s;直流驱动时指标分别为400.8μV/(°)s-1、12.129%、15.29%、4 803°/s和43.5°/s。结果表明:从综合指标方面看交流电压驱动方式和相关检测方案下测量效果最佳。

The operational principles of micro-fluidic gyros were introduced. Two kinds of drive modes for micro-fluidic gyroscope,DC drive and AC drive, were presented, the influence of the drive modes on the performance of output signals was analyzed. While the DC actuated, the Coriolis acceleration induced by an external angular velocity could cause the deflections of fluid velocity to cool the thermo- couples oppositely, then, the temperature disturbances of thermocouples were converted to a DC differential output voltage proportional to the angular velocity. On the other hand, while the AC ap- plied, the required signals included in sine wave velocity could be selected out with the use of the Phase Sensitively Demodulation （PSD）, low-pass filters and the amplifiers and the DC voltage proportional to the external angular velocity was obtained. The experimental results indicate that the scale factor and its nonlinearity and the symmetry are 17.05μV/（°）s^-1, 5. 725% and 4.52%, and the zero drift and the stability of output signals are 1 066 °/s and 14.3 °/s by AC drive, while the correspond- ing results are 400.8μV/（°）s 1, 12.129°, 15.29°, 4 803 °/sand43.5 °/sbyDCdrive. It comes to the conclusion that the micro-fluidic gyroscope has better performance by the AC drive and correlation detection.