针对某些高过载应用场合对微机械加速度计抗冲击能力的要求, 设计了一种三轴向抗冲击的梳齿电容式闭环微机械加速度计。通过分析带止档的闭环加速度计冲击响应过程, 提出在敏感方向使用悬臂梳齿结构作为柔性缓冲止档可以缓冲冲击过程中微结构间的接触碰撞; 在非敏感方向采用结构模态和阻尼分离的设计可减小冲击变形, 耗散冲击能量。马歇特锤冲击实验表明, 该加速度计能够分别承受3个轴向幅值为13 200g, 脉宽约102 μs的的加速度冲击, 冲击前后偏置漂移在5 mV以内。该闭环加速度计在±10g的非线性优于500×10-6, 1.5 h偏置稳定性为0.27 mg。设计的样机基本满足高过载环境下惯性测量的要求。

In consideration of the requirements of micro-machined accelerometers for enduring shock pulses in some special high-overload applications, a comb-finger capacitive closed-loop accelerometer with triaxial shock resistance was proposed. After analysis of the shock response of the closed-loop accelerometer with a stop, it points out that the flexible comb stop designed in the sensitive direction can reduce the impact force among the micro-structures and the modal separation and damping in the insensitive direction to strengthen the shock resistance in y and z axes can reduce the deformation and dissipate the shock energy. An impact hammer test demonstrates that the accelerometer can resist the acceleration shocks by 13,200g, and 102 μs respectively, and the bias drifts is less than 5 mV after shock. A prototype was designed and its nonlinearity is less than 500×10-6 in a full scale of ±10g, its bias stability is 0.27 mg for 1.5 h. The prototype can basically meet the demands of inertial measurements under high overload conditions.