爆炸冲击环境下MEMS加速度传感器的零漂分析

本文以石油行业中的爆炸冲击为研究背景,研究了MEMS加速度传感器在爆炸冲击环境下测量时存在的零漂问题的原因及解决方案.采用和MEMS加速度传感器电气模型等效的电阻式应变电桥,通过大量试验,排除了电路串扰、应变片自生信号等可能的原因,确定了电缆内由于摩擦生电效应产生的干扰信号是形成零漂的重要原因.在此基础上,选择不同类型的电缆进行了对比试验.试验结果表明:电缆的大柔性和低机械阻抗能够减少物理运动和应力波耦合的影响,石墨填充剂可将摩擦生电效应产生的电荷引入电气地,从而可有效改善MEMS加速度传感器在爆炸冲击环境下测量时存在的零漂问题.

Analysis of Zero Shift in MEMS Accelerometers Signals Under Pyroshock Environment

In this paper,the cause and solution of zero shift in MEMS accelerometers signals were researched under the background of the pyroshock in the oil industry.The paper adopts a resistive strain gage bridge equivalent to electrical model of MEMS acceleration sensor.With extensive tests,it disproves that the signal conditioning electronics cross talk and the strain gages themselves are sources of signal noise generation.It shows that the interference signal generated by the triboelectric effect in the cable was determined to be an important reason for the formation of zero drift.On this basis,comparative tests were then carried out with different cables.The results show that cables with increased flexibility and much lower mechanical impedance make them more impervious to physical movement and stress wave coupling.A static dissipative material such as graphite in the cable will allow the transfer of charge buildup due to triboelectric effects to electrical ground.By these means,the zero shift in MEMS accelerometers signals under pyroshock environment can be greatly reduced.