基于Fabry-Perot干涉仪的闭环微光机电加速度计

MOEMS accelerometer based on double Fabry-Perot interferometers and closed loop

设计了一种闭环反馈差动式双FP腔的微光机电(MOEMS)加速度计,介绍了其工作原理及系统构成.利用惯性敏感单元将对载体加速度的测量转变为对载体位移的测量,利用光纤自聚焦透镜的端面与质量块组成的FP腔测量载体位移.为了提高系统的测量灵敏度和抑制温度等环境因素的影响,设计了一种差动式双FP腔测量机构.为提高微加速度计的输出线性度和动态测量范围,提出了采用静电力平衡技术构成闭环加速度计.建立了其数学模型,对所设计的加速度计重要参数指标———灵敏度、敏感头受载、固有频率等一一进行了详细计算和分析.在此基础上完成了设计背景要求下加速度计参数的优化设计,结果表明:该系统精度可以达到5×10-6g以上.

A micro-opto-electro-mechanical accelerometer based on differential double Fabry-Perot interferometers（DFPI） and closed loop was designed. The principle and the structure of the accelerometer were introduced. Inertial sensitive module was used to translate carrier＇s acceleration measurement to its displacement measurement. The displacement was measured by Fabry-Perot interferometers composed of the mass and the end surface of fiber self-focusing lens. The structure of differential DFPI was designed to improve the sensitivity and restrain the influence of environment factors such as temperature. The closed loop accelerometer using electrostatic servo technology was put forward to improve the output linearity and dynamic range. The mathematic model of the accelerometer was founded, and particular calculation and analysis was made for important parameters, such as sensitivity, carrying capacity of the sensitivity head, natural frequency, etc. The parameters were designed under the requirement of some background. The results show that the system precision can be better than 5 ×10^-6g.