叠加电桥检测的加速度传感器设计

基于压阻效应的叠加电桥检测法加速度传感器采用超对称"八悬臂梁—质量块"结构,构成惠斯通电桥的力敏电阻器布放在悬臂梁的两端,4个惠斯通电桥的输出电压叠加后作为传感器的最终输出,有效提高了加速度传感器的灵敏度。通过数学建模仿真分析验证了方案的可行性。性能测试结果表明:该加速度计的灵敏度为1.1381mV/gn,频响范围为0～1000Hz,灵敏度约为单电桥检测法和串联电桥检测法加速度传感器灵敏度的4倍。叠加电桥检测法为压阻式传感器提高灵敏度提供了一种新思路。

Design of acceleration transducer for superimposed bridge detection

Superimposed bridge detection method acceleration transducer based on piezoresistive effect adopts ultra symmetrical structure with eight cantilevers and one mass,by placing the force sensitive resistors composed of Wheatstone bridge on the two ends of each cantilever respectively,and taking the superimposed output voltages of the 4 Wheatstone bridges as the final output of transducer,which effectively improve sensitivity of the acceleration transducer.The scheme is proved to be feasible through mathematical modeling simulational analysis.Results of performance test shows that the sensitivity of the accelerometer is 1.138 1 mV/gn,which is about four times of the sensitivity of the single bridge and the in-line bridge detection method,and the frequency response range is 0 ~1 000 Hz.In addition,the superimposed bridge detection method provides a new thought for improving the sensitivity of piezoresistive transducer.