声表面波梁式加速度传感器的优化设计

为获得传感器的优化设计,对一种声表面波梁式加速度传感器敏感机理进行了研究。从声波波动方程出发,结合有限元分析以及微扰理论对加速度作用力作用下声表面波传播特性进行分析,以此构建梁式声表面波加速度传感器敏感机理的理论模型,特别分析了压电梁材料及几何结构、振子质量对传感响应的贡献以确定传感器优化的几何参数。为验证理论分析结果,实验研制了基于ST-X石英悬臂梁结构的差分振荡式声表面波加速度传感器,并利用精密振动台对所研制传感器性能进行评价。实验结果显示,在给定加速度测试范围内,采用ST-X石英梁并延长梁长度、降低梁厚度以及采用较大的阵子质量将有效的改善传感器检测灵敏度,在±2 g范围内加速度灵敏度可达27 k Hz/g,且实验结果很好的验证了理论模型。

The optimization design of surface acoustic wave acceleration sensor with cantilever beam structure

For the sensor optimization design, the sensitive mechanism of surface acoustic wave acceleration sensor with cantilever beam structure was studied. Starting from the acoustic wave equation, combined with finite element analysis and perturbation theory, surface acoustic wave propagation characteristic was analyzed under the action of the acceleration force in order to build theory model of the sensitive mechanism of the sensor, especially the contribution of the material and geometric structure of piezoelectric beam and proof mass to the sensor response for the purpose of determining the optimized geometric parameters of the sensor. To verify the theoretical analysis results, a surface acoustic wave acceleration sensor based on ST-X quartz cantilever beam structure with differential oscillator was developed, and the performance of the developed sensor was evaluated by using the precise vibration table. The experimental results showed that adopting ST-X quartz, extending the length of the beam, decreasing the thickness of the beam and increasing the proof mass could all improve the sensitivity of the sensor within a given acceleration test range, and the optimized detection sensitivity obtained was 27KHz/g within ±2g, which well verified the theory model.