耐高冲击过载电容式微加速度计设计

针对近年来常规弹药制导化改造对经历高动态环境的加速度传感器的迫切需求,该文设计了一种抗高过载、低量程的微机电系统(MEMS)电容式加速度传感器。该加速度传感器使用4组折叠梁组对可动结构进行支撑,并带动其在敏感方向移动,同时敏感结构采用差分式电容检测结构和叉齿止档限位结构方案,降低了结构受冲击时的区域应力,提高了输出信号增益及传感器灵敏度。理论计算和有限元分析结果表明,传感器轴向灵敏度为0.22 pF/g(g=9.8 m/s²),可承受轴向幅值为3×10⁴g、脉宽约8 ms的加速度冲击。

Design of a Resistant High ShockOverload Capacitive MEMS Accelerometer

Aiming to developing efficient accelerometers for the guidance of conventional ammunition with high dynamic property, a MEMS capacitive acceleration sensor with high overload resistance and low range is designed, where four groups folding beams were used to support the movable structure and drive it to move along the sensitive direction.The differential capacitance detection structure and the interdigital stop limiting structure were employed to reduce the stress concentration in the process of impactand improve the sensitivity significantly. Theoretical calculation and finite element analysis show that the axial sensitivity of the sensor is 0.22 pF/g(g=9.8 m/s²), and the proposed sensor has the ability to resist an axial acceleration shocks of 3×10⁴g with a pulse width of 8 ms.