摘要
针对航空矢量声纳浮标对低噪声、低成本、小体积惯性传感器的需求,研究了一种基于双压电晶片的双轴压差分式压电加速度计。首先从理论上分析了矢量水听器中加速度计的工作模式,基于压电加速度计自噪声模型,提出了利用双压电晶片与独立质量块结构实现低噪声加速度计的方法;通过有限元方法对加速度计的灵敏度和谐振频率开展优化设计,确定了加速度计各部件的结构参数;根据优化结果研制了一只加速度计样机及前置放大电路。样机测试结果表明,该压电加速度计整体尺寸为56 mm×56 mm×35 mm,一阶谐振频率约为7.4 kHz,两个轴向的灵敏度分别为1556 pC/g及1363 pC/g(100 Hz),横向灵敏度小于轴向灵敏度的2%。压电加速度计的自噪声为38 ng/√Hz(1 kHz,等效噪声声压级为39 dB/√Hz),低于零级海况下的海洋环境噪声。
A biaxial differential piezoelectric accelerometer utilizing piezoelectric bimorphs is researched devoting to developing low-noise,low-cost and compact inertial sensors used in airborne acoustic vector sonobuoys.Working model of the accelerometer in the acoustic vector sensor is analyzed theoretically,and self-noise reduction methods of the accelerometer using a bimorph structure and independent mass are proposed according to the theoretical self-noise model.The sensitivity and resonance frequency of the accelerometer are optimized by the finite element method,and the structural parameters of components are obtained.An accelerometer prototype and the associated preamplifier are developed on the basis of optimization results.Experimental results show that the overall size of the piezoelectric accelerometer is 56 mm×56 mm×35 mm,and the resonance frequency is about 7.4 kHz.The two-axial sensitivities are 1556 pC/g and 1363 pC/g(100 Hz)respectively,and the transverse sensitivities are less than 2%of the axial sensitivities.The self-noise of the piezoelectric accelerometer is 38 ng/√Hz(1 kHz,the equivalent noise sound pressure level is 39 dB/√Hz),which is lower than the ambient sea noise of zero sea state.
作者
周宏坤
洪连进
程启航
ZHOU Hongkun;HONG Lianjin;CHENG Qihang(State Key Laboratory of Deep-sea Manned Vehicles,China Ship Scientific Research Center,Wuxi 214082,China;Acoustic Science and Technology Laboratory,Harbin Engineering University,Harbin 150001,China;Hangzhou Applied Acoustics Research Institute,Hangzhou 310023,China)
出处
《中国惯性技术学报》
EI
CSCD
北大核心
2020年第4期469-473,共5页
Journal of Chinese Inertial Technology
基金
国家自然科学基金项目(11904330)
江苏省自然科学基金项目(BK20180171)。
关键词
双压电晶片
加速度计
低噪声
矢量水听器
piezoelectric bimorph
accelerometer
low self-noise
acoustic vector sensor
