分析了用于PZT形变-力传感-位移量传递模式实时检测的厚膜电容位移传感器的非线性问题,对传感器弹性膜片产生挠性形变以及位移检测带来的非线性问题做了系统的分析并给出了在小挠度形变情况下电容计算公式。仿真结果表明:在电容极板间隙为50μm、膜片厚度为0.55 mm、工作半径为10 mm、膜片中心偏移量为5μm的情况下,与普通极板电容计算公式相比,采用小挠度形变电容计算公式可使位移检测精度提高4.74%。
Analysis of nonlinear error was presented for thick film capacitor micro displacement measurement sensor which measured the PZT displacement based on the pattern of PZT deformation-force sensing-displacement. This paper systematically analyzed the deflection deformation of elastic diaphragm which may cause nonlinear error in displacement measurement and a capacitance calculation formula was developed under small deflection deformation. The simulation results show that the measuring accuracy can be improved about 4.74% when the developed calculation formula is used in the case of capacitor polar plates clearance is 50 μm, diaphragm thickness is 0.55 mm, working radius is 10 mm and the deflection of diaphragm center is 5 μm.