大量程闭环MEMS加速度计非线性分析与优化法

为研究大量程翘翘板摆式闭环MEMS加速度计系统的输出非线性,分别从质量块受力不平衡所产生的平动效应以及电路零位引起质量块闭环平衡位置偏差两个主要误差源入手,建立了两种误差引起加速度计非线性的数学模型,并采用ANSYS和Simulink软件对传感器结构及系统进行了仿真验证,确定了该模型的正确性及非线性的优化方法。最后,按照以上分析进行了样机制作和离心测试。试验结果表明,通过减小翘翘板摆式结构质量块的平动效应,可将±150g量程加速度计的非线性由5.4979′10-2减小至5.320′10~(-3),在此基础上通过减小质量块闭环平衡位置偏差,可进一步将加速度计的非线性减小至2.772′10~(-3)。

Analysis and optimization on nonlinearity of large-range closed-loop MEMS accelerometer

In order to study the output nonlinearity of large-range see-saw pendulum closed-loop MEMS accelerometer,a nonlinearity model of the accelerometer is built from the following two main error sources:the translational effect of the proof mass due to force unbalance,and the closed-loop equilibrium position deviation due to electronic offset.Then,according to the sensor structure and system simulation with the software of ANSYS and Simulink,the correctness of the model and the optimizing method of the nonlinearity are confirmed.At last,the accelerometers prototypes are designed and tested with centrifuge.The test results show that,by reducing the translational effect of the proof mass with large-range see-saw pendulum structure,the nonlinearity of the accelerometer with ±150g range can be reduced from 5.4979× 10-2 to 5.320×10-3,and can be further decreased to 2.772×10-3 by reducing the deviation of proof mass closed-loop equilibrium position.