振动校准加速度计频率响应不确定度的确定方法

Determination Method of Uncertainty of Accelerometer Frequency Response for Vibration Calibration

提出一种基于蒙特卡罗数值计算方法的加速度计频率响应不确定度确定方法。该方法针对绝对法振动校准实验数据,采用加权最小二乘算法辨识出了等效模型参数及其不确定度,利用参数关系确定了加速度计二阶模型参数及其不确定度,结合蒙特卡罗数值计算方法得到了加速度计频率响应非参数模型的不确定度曲线。实验结果表明,该方法稳定可靠,能得到加速度计频率响应全频段的不确定度,较振动校准获得的离散频率点处对应的不确定度,将离散频率点处的不确定度扩大至频率响应全频段范围内,为校准过程中不确定评定提供参考。

A method for determining the uncertainty of the frequency response of the accelerometer based on the Monte Carlo numerical calculation method was proposed.In this method for the data of primary vibration calibration,the parameters of the equivalent model of the accelerometer were identified by the weighted least square method.The parameters and its uncertainty of the two order model were determined by using the parameter relation.And by combining with the Monte Carlo numerical calculation method,the dynamic characteristic frequency response uncertainty curve of the accelerometer was obtained.The experimental results show that the method is stable and fast,and can get the uncertainty of the whole frequency response.Compared with the uncertainty of the discrete frequency points obtained by the vibration calibration,the uncertainty of the discrete frequency point is extended to the full range of frequency response,which provides reference for the calibration process.