地震勘探用电容式闭环微加速度计的仿真

MEMS加速度传感器大幅提高了新型地震检波器的各项性能指标。利用有限元软件AN-SYS建立了悬臂硅梁的力学模型,并通过其力学性能仿真,得出优化的设计结构尺寸,即梁长L=150μm,梁宽b=40μm,梁厚h=4μm,活动电极和固定电极的间距d0取为1μm。同时利用电路仿真软件建立了传感器闭环系统的整体仿真数学模型,仿真结果表明其阶跃响应和正弦响应基本和理论分析结果吻合,传感器的分辨率可达0.001 m/s2,频带宽度可达500 MHz。该基于MEMS加速度传感器的新型地震检波器在地震勘探中将具有广阔的应用前景。

Closed-Loop System Simulation of the Capacitive Micro-Accelerometer for the Seismic Exploration

The performances of the new geophone are significantly improved by the MEMS acce-leration sensors.The mechanical model of the silicon cantilever beam was set up by means of the finite element software ANSYS,and the best design structure size was gained through the stimulation of the mechanical properties.The design result shows that the length L is 150 μm,the width b is 40 μm,the thickness h is 4 μm,and d0 is 1 μm(d0 is the space between the moving electrode and fixed electrode).Meanwhile,the overall mathematical model of the closed-loop system was established using the sensor circuit simulation software.The simulation results show that the step response and sinusoidal response agree well with the result of the theoretical analysis.The sensor resolution and bandwidth are up to 0.001 m/s2 and 500 MHz,respectively.The new-type geophone based on the MEMS acceleration sensor will have wide application prospects in the seismic exploration.