Abstract:
We simulated the effects of gimbal-alignment errors and rotational step-size errors on measurements of the sensitivity matrix and intrinsic properties of a triaxial accelerometer. We restricted the study to measurements carried out on a two-axis calibration system using a previously described measurement and analysis protocol. As well as imperfections in the calibration system, we simulated imperfect orthogonality of the accelerometer axes and non-identical sensitivity of the individual accelerometers in an otherwise perfect triaxial accelerometer, but we left characterization of other accelerometer imperfections such as non-linearity for future study. Within this framework, sensitivity-matrix errors are caused by imperfections in the construction and installation of the accelerometer calibration system, but not by the accelerometer imperfections included in the simulations. We use the results of this study to assign type B uncertainties to the components of the sensitivity matrix and related intrinsic properties due to imperfections in the measurement system. For calibrations using a reasonably well manufactured and installed multi-axis rotation stage such as that studied in this paper, we estimated upper bounds to the standard uncertainties of the order of 1×10-5, 2×10-5, 5×10-5, and 2×10-4 for the intrinsic sensitivities, diagonal elements of the sensitivity matrix, off-diagonal elements of the sensitivity matrix, and zero-acceleration offsets, relative to a sensitivity-matrix element of 1, respectively, and 5×10-3 degrees for the intrinsic angles.
摘要:
我们模拟了万向节对准误差和旋转步长误差对三轴加速度计灵敏度矩阵和固有特性测量的影响。我们将研究限制为使用先前描述的测量和分析方案在双轴校准系统上进行的测量。以及校准系统中的缺陷,我们模拟了加速度计轴的不完美正交性和不同灵敏度的单独加速度计在一个完美的三轴加速度计,但我们留下了其他加速度计缺陷的表征,如非线性,以备将来研究。在这个框架内,灵敏度矩阵误差是由加速度计校准系统的构造和安装中的缺陷引起的,但不是因为模拟中包含的加速度计缺陷。由于测量系统中的缺陷,我们使用这项研究的结果将B型不确定性分配给灵敏度矩阵的组成部分和相关的固有特性。对于使用合理的制造和安装好的多轴旋转台进行校准,例如本文研究的,我们估计了1×10-5,2×10-5,5×10-5和2×10-4的标准不确定度的固有灵敏度的上限,灵敏度矩阵的对角元素,灵敏度矩阵的非对角元素,和零加速度偏移,分别相对于灵敏度矩阵元素为1,和5×10-3度的固有角度。