Revised error calibration model of linear accelerometer on precision centrifuge.

The common error calibration model of a linear accelerometer usually cannot meet the accuracy requirement without considering the influence of misalignments in the precision centrifuge test. In order to improve the calibration accuracy, a series of coordinate systems is established and precise accelerations along the input axes of the accelerometers are deduced first. Then, by analyzing the mechanisms of the main error sources, the revised error calibration model is established which includes the misalignments, the radius errors, and the nonlinearity error terms. Then, the measurement methods are proposed to estimate the initial angular misalignments, the installation angular misalignments, and the installation radius misalignments by a theodolite and the accelerometer themselves in the different modes of the centrifuge, respectively. Finally, the experimental measurement results show that the initial angular misalignments are estimated accurately and less than 0.5' after adjustment. Further investigation shows that the adequacy of the common error calibration model decline obviously and the calibration accuracies are lower than 6 × 10-3g/g without considering the misalignments. After compensating for the misalignments in the revised model, the error coefficients are identified precisely, and the calibration accuracies are higher than 1.5 × 10-3g/g.