存在初始位移的MEMS振动台的振动特性分析  

Analysis of vibration characteristics of MEMS vibration table with initial displacement

作　　者：郝瑞 周吴 彭倍 Hao Rui;Zhou Wu;Peng Bei(School of Mechanical and Electrical Engineering,University of Electronic Science and Technology of China,Chengdu 611731,China)

机构地区：[1]电子科技大学机械与电气工程学院,成都611731

出　　处：《仪器仪表学报》2021年第11期71-78,共8页Chinese Journal of Scientific Instrument

基　　金：国家自然科学基金(52075082,51975107);四川省科技厅区域创新合作项目(2020YFQ0017)资助。

摘　　要：MEMS压电振动台能够实现微米量级的精密机械振动,应用于MEMS惯性传感器的片上标定。然而,由于压电陶瓷和硅的热膨胀系数不同,导致MEMS压电梁在制造成形后存在残余应力。残余应力会引起MEMS压电梁的翘曲,并导致MEMS压电振动台存在初始位移。为分析初始位移对MEMS压电振动台的振动特性的影响,建立残余应力与压电梁变形间的关系,以及压电梁变形与振动台初始位移间的关系。将初始位移量引入MEMS压电振动台的振动模型中,讨论不同初始位移(10、20、30μm)MEMS压电振动台的振动特性。实验结果表明在10 V(150 Hz)正弦激励下,存在初始位移的MEMS压电振动台具有双稳态振动特性,振动波形失真最大相对误差为45%。实验结果与理论分析吻合证明残余应力是引起振动波形失真的主要原因。The MEMS piezoelectric vibration table can achieve micron-level precision mechanical vibration,which is applied to the on-chip calibration of MEMS inertial sensors.However,the thermal expansion coefficients of piezoelectric ceramics and silicon are different,which could result in residual stresses in MEMS piezoelectric beams after manufacturing and forming.The residual stress may lead to the warpage of the MEMS piezoelectric beam and cause the vibration table to have the initial displacement.To analyze the influence of the initial displacement on the vibration characteristics of the MEMS piezoelectric vibration table,the relationship among the residual stress,the deformation of piezoelectric beam and the initial displacement of vibration table is established.Then,the initial displacement is introduced into the vibration model of the MEMS piezoelectric vibration table,and the vibration characteristics of the MEMS piezoelectric vibration table with different initial displacements(10、20 and 30μm)are discussed.Experimental results show that under 10 V(150 Hz)sinusoidal excitation,the MEMS piezoelectric vibration table with the initial displacement has bistable vibration characteristics and the vibration waveform distortion,and the maximum relative error is 45%.Results are consistent with the theoretical analysis and prove that the residual stress is the main cause of the distortion of the vibration waveform.

关 键 词：初始位移 MEMS振动台 双稳态振动 波形失真 MEMS加速度计标定 

分 类 号：TH703[机械工程—仪器科学与技术]