Gaitan Michael, Bautista Iris Mariela López, Geist Jon
National Institute of Standards and Technology Gaithersburg, MD 20899, United States of America.
Centro Nacional de Metrología Querétaro, C.P. 76246, México.
Metrologia. 2021 Apr 13;58(3). doi: 10.1088/1681-7575/abeccf.
We show that the calibration of tri-axis accelerometers based on the device's intrinsic properties alleviates the uncertainty due to mounting misalignment in comparison to the use of the sensitivity matrix. The intrinsic properties of a tri-axis accelerometer are based on a (, v, ) coordinate system that represent the direction of maximum sensitivities of each of the three accelerometers () and are assumed not to be perfectly orthogonal to each other. The calibration procedure requires rotation of the device in the gravitational field around each of the Cartesian coordinate () axes. One component in driving down the uncertainty of laboratory comparisons and calibration repeats relates to misalignment in mounting the device onto the calibration instrument. We show that the uncertainty of the cross-axis terms of the sensitivity matrix is a dominating factor affecting uncertainty down to a 0.01° misalignment at a 100 μV noise level. The misalignment component can be exacerbated when calibrating modern microelectromechanical systems (MEMS)-based accelerometers, which are typically a few millimeters in dimension.
我们表明，与使用灵敏度矩阵相比，基于设备固有特性对三轴加速度计进行校准可减轻由于安装未对准而产生的不确定性。三轴加速度计的固有特性基于一个（，v，）坐标系，该坐标系表示三个加速度计（）各自的最大灵敏度方向，并且假定彼此不完全正交。校准过程需要在重力场中围绕笛卡尔坐标（）轴中的每一个旋转设备。降低实验室比较和校准重复的不确定性的一个因素与将设备安装在校准仪器上的未对准有关。我们表明，在100μV噪声水平下，灵敏度矩阵的交叉轴项的不确定性是影响低至0.01°未对准的不确定性的主要因素。在校准基于现代微机电系统（MEMS）的加速度计时，未对准分量可能会加剧，这种加速度计的尺寸通常为几毫米。
