基于功率谱密度的静电悬浮加速度计分辨率估计方法  

Method for Resolution Estimation of Electrostatically Suspended Accelerometer Based on Power Spectrum Density(PSD)

作　　者：刘爽[1] 刘云峰[1] 董景新[1] 

机构地区：[1]清华大学精密仪器系,高精度导航技术教育部重点实验室,北京100084

出　　处：《仪表技术与传感器》2015年第10期30-34,共5页Instrument Technique and Sensor

基　　金：清华大学自主科研计划(20091081243)

摘　　要：高精度静电悬浮加速度计常采用功率谱密度估计（PSD）来评估分辨率水平,商用PSD分析仪需实时在线分析,且分析时间长、频域分辨率低、成本高。为此提出了一种线下PSD估计方法,利用简易采集系统采集噪声信号,再进行PSD估计。给出了正确的PSD估计表达式,推导了加速度计分辨率与PSD的关系,通过实验对比了该方法与HP35670A动态分析仪分析结果,实验结果验证了该方法的有效性。最后用该方法分析了研制的静电悬浮加速度计原理样机X1、Y和Z2三个通道加速度噪声的PSD,得到0.1 Hz处PSD分别为：8.07×10-5g/Hz1/2、3.29×10^-8g/Hz1/2和2.39×10^-7g/Hz1/2;在带宽0.001~0.1 Hz内分辨率分别为4.64×10^-5g、4.21×10^-8g和1.51×10^-7g。Power spectrum density（ PSD） estimation is always used to evaluate the resolution of electrostatically suspended accelerometer（ ESA）. Commercial instrument for the PSD estimation need online estimating,and there are some other shortcomings,such as low frequency resolution and high cost. So a simple method for PSD estimation was proposed. The theory and formation of the method were given,so was the relation between PSD and resolution of ESA. The results of PSD,which were got by this method and HP35670 A dynamic analyzer,show that this method was valid. At last,the PSD in X1,Y and Z2 channels of ESA using this method was evaluated. The noise PSD at 0. 1 Hz are 8. 07 × 10^- 5,3. 29 × 10^- 8and 2. 39 × 10^- 7g / Hz1 /2,respectively. The resolution in the 0. 001 ~ 0. 1 Hz are 4. 64 × 10^- 5g,4. 21 × 10^- 8g and 1. 51 × 10^- 7g respectively.

关 键 词：功率谱密度估计 维纳辛钦定律 WELCH法 静电悬浮加速度计 

分 类 号：U666.1[交通运输工程—船舶及航道工程]