Bias warm-up time is the time required for MEMS gyroscopes to reach a relatively stable state with specified performance after the power supply is turned on, is a critical factor for short time-of-flight navigation applications. This paper demonstrates an effective method to improve the bias warm-up time of a custom-designed MEMS gyroscope operating in split-mode based on open-loop readout scheme with active suppression of the coupling stiffness (ASCS). A semi-quantitative mathematical model for the temperature sensitivity of the bias is established that indicates the resonant frequency of the primary mode, the frequency difference and the coupling stiffness between the primary and sense modes together with the demodulation phase error, and these are the main factors that affect bias warm-up time. Of all these parameters, the stiffness coupling variation contributes the most to the start-up warm-up time, followed by the phase error drift. The experimental result shows that the bias warm-up time decreases from 2000 to 2 s under the condition that the bias stability (1σ) falls into about 10 deg/h within an hour of testing time using closed-loop control for the coupling stiffness, resulting in a reduction of three orders of magnitude. In addition, the bias instability of the gyroscope is improved two-fold from 4 to 2 deg/h with ASCS.

偏置预热时间是MEMS陀螺仪在接通电源后达到具有规定性能的相对稳定状态所需的时间，是短时间飞行导航应用的关键因素。本文展示了一种有效的方法来改善定制设计的 MEMS 陀螺仪的偏置预热时间，该陀螺仪基于开环读出方案以主动抑制耦合刚度 (ASCS) 的方式在分离模式下运行。建立了偏置温度敏感性的半定量数学模型，该模型指示了主模的谐振频率、主模与感测模之间的频率差和耦合刚度以及解调相位误差，这些是主要的影响偏置预热时间的因素。在所有这些参数中，刚度耦合变化对启动预热时间的贡献最大，其次是相位误差漂移。实验结果表明，在偏置稳定(1σ ) 在一个小时的测试时间内下降到大约 10 度/小时，使用闭环控制耦合刚度，导致三个数量级的降低。此外，陀螺仪的偏置不稳定性通过 ASCS 提高了两倍，从 4 度/小时到 2 度/小时。