Sequential Calibration Method of Nonlinear Errors of PIGA on Counter-Rotating Platform Centrifuge

This article proposes a new method for calibrating nonlinear errors of pendulous integrating gyro accelerometer (PIGA) on the precision centrifuge with a counter-rotating platform, which can provide both constant and harmonic input accelerations. First, by analyzing the working principle and error sources of the centrifuge, corresponding coordinate systems are established. With the homogeneous transformation method, the precise input accelerations and angular velocities of PIGA in the centrifuge test are derived, and the error calibration models are established. Then, the sequential calibration method is designed by combining the symmetrical position test with a synchronous counter-rotating test. This sequential method has the advantage of installing PIGA on the centrifuge only once. Not only the nonlinear error coefficients are identified but also the centrifuge errors, the misalignments of PIGA with the centrifuge, and the installation errors of PIGA on the centrifuge are effectively suppressed simultaneously. Experiments are presented and discussed to illustrate the effectiveness of the proposed method.