八腿椭圆形变截面梁加速度计系统结构设计

Structure Design of the Eight-prong Legged Accelerometer Based on Oval Variable Cross-section Beam

根据加速度计对灵敏度、稳定性、噪声和品质因子等性能指标要求,提出一种八腿椭圆形变截面梁和带有阻尼孔检测质量块的加速度计结构。选用八腿椭圆形变截面梁增大非检测方向刚度,减小交叉灵敏度并提高工作稳定性;减小检测方向刚度,增大系统灵敏度。对检测质量块作均匀挖孔处理,减小系统阻尼,减小机械热噪声及增大品质因数,从而提高分辨率。文中建立加速度计力学模型,并描述其工作原理。建立梁的纯弯曲模型,推导出梁的刚度公式。对质量块开孔情况进行比较,给出了提高分辨率的方法。

According to the performance such as sensitivity,stability,noise and quality factor of the accelerometer,this paper presents a new type of accelerometer with eight-prong legged oval variable beam and proof mass with damping holes.This beam increases the non-detection directional stiffness,thereby reducing cross sensitivity and improving stability;It can also reduce the detection direction stiffness,thereby increasing the sensitivity of system.In order to obtain a higher resolution,the proof mass with uniform damping holes is required.It can greatly reduce the system damping,decrease the mechanical thermal noise and increase the quality factor.In this paper,the model of the accelerometer is established,and its principle is described.The pure bending model of the beam is established,and the stiffness formula of the beam is derived.The method of improving the resolution is given by making holes on the proof mass.