摘要
针对硅基微机械加速度计零偏往往随温度改变而漂移的问题,设计了一种新型的温度补偿电路. 通过理论研究和实验测试,发现微机械加速度计谐振频率与温度呈现非常好的线性关系.谐振频率与表头弹性梁的弹性系数的二次方根呈正比关系,而温度对于弹性系数的影响主要有3 方面：弹性模量随温度的改变、机械热膨胀和热应力.通过Matlab 数值仿真的方法,仿真和模拟了加速度计表头固有谐振频率与温度的关系,该仿真结果与实验测试结果符合得很好.基于以上分析,提出了一种新型温度补偿电路,通过在FPGA 中设计数字锁相环模块实时检测和跟踪加速度计当前温度下的谐振频率值作为温度信号,进而补偿系统零偏输出. 结果表明：在-30～60,℃全温度范围内,补偿后系统温漂峰峰值由初始的541.8,mg 降低到46.0,mg,满足了工程应用需求.
Considering the changes of the zero bias of a silicon-based MEMS accelerometer at different environmental temperatures,a new type of compensation circuit was designed. Theoretical analysis and experimental tests showed that there was a significant linearity between resonant frequency and temperature. The resonant frequency was propor-tional to the square root of elasticity modulus of elastic beam. Meanwhile,the temperature affected elasticity modulus in three main ways:the temperature effect of the elasticity modulus,thermal expansion and thermal stress. By means of Matlab numerical simulation,the relationship between resonant frequency and temperature was modeled and simu-lated,which well agreed with the experimental results. Based on the above study,a circuit with digital PLL module was designed for temperature compensation using FPGA. By identifying and locking the resonant frequency of the accelerometer,the resonant frequency worked as a symbol of temperature deviation so as to compensate zero bias drift. The result shows:after the compensation,the peak to peak temperature driftof the system decreases from 541.8,mg to 46.0,mg in the range from-30,℃ to 60,℃,meeting the requirements of some industrial applications.
出处
《天津大学学报（自然科学与工程技术版）》
EI
CAS
CSCD
北大核心
2015年第7期658-662,共5页
Journal of Tianjin University：Science and Technology
基金
中央高校基本科研业务费专项资金资助项目(2012QNA4021)
浙江省自然科学基金资助项目(Q13F040001)
关键词
加速度计
谐振频率
温度补偿
accelerometer
resonant frequency
temperature compensation
