改善MEMS陀螺误差温度稳定性的驱动力补偿方法

Driving-force compensation to improve the bias thermal stability of MEMS gyroscopes

由于微机电系统(MEMS)陀螺通常采用微加工工艺生产制造,因此总是受微加工过程带来的的各种精度缺陷影响。对于MEMS陀螺,其零位输出误差因受环境因素影响而无法保持稳定,随时间表现出漂移特性,这种特性严重限制了MEMS陀螺在更高精度应用中的可用性。该文研究了一种改善MEMS陀螺零位误差温度稳定性的方法。通过分析陀螺运动特性及主要误差源,阐明陀螺驱动力对检测方向的耦合作用是零偏误差同相分量产生并随温度漂移的主要原因之一。为抑制陀螺驱动力耦合作用,提出对陀螺检测轴施加补偿静电力的方法。温度试验结果表明:施加补偿作用后,陀螺零偏误差同相分量的温度稳定性在12～60℃范围内提高了3倍以上。

Micro electro-mechanical system （MEMS） gyroscopes can be manufactured using micro machining procedures, but they are all subjecl to unavoidable defects related to the fabrication processes. The zero-rate output （ZRO） of a MEMS gyroscope is known to vary with the environment which severely restricts high-precision applications. This paper presents a method to improve MEMS gyroscope lhermal stability during temperature variations. Analysis of the gyro＇s error sources and fundamental dynamics show that the coupling of driving forces has a crucial effect on the in phase ZRO and also contributes to the instabilities of the gyro＇s bias. The coupling of the gyro driving forces can be suppressed by electrostatic force compensalion applied to the sensing axis with temperature tests showing thai the gyro bias is three times more stable after compensation for temperatures of 12 - 60℃.