Multi-Position Calibration Method of Gyroscopes in Inertial Measurement Unit Based on Centrifuge with Position Platform

In order to accurately calibrate the static error model coefficients of three gyroscopes simultaneously, especially the higher-order coefficients, in an inertial measurement unit, an optimal 16-position method is designed. Analysis is conducted using a precision centrifuge with a counter-rotating platform, and coordinate systems are established on centrifuge. Thus, centrifuge error sources, which may affect the calibration accuracy of a gyroscope’s drift coefficients, are analyzed, corresponding to the coordinate systems established. Precise expressions for the input angular rate and the input specific forces on each axis of the three gyroscopes are derived using a homogeneous transformation method. The influence of centrifuge error on the drift coefficients is analyzed, and the calibration accuracy can be improved by compensating for the influence of centrifuge error. The 16-position calibration method is validated through simulation, which establishes that centrifuge errors such as Δθy2t, Δθy2(−Ωt), Δθx2t, Δθx2(−Ωt), and ΔΩ mainly influences the bias MF and first-order drift coefficients MI and MS, but has little impact on higher-order coefficients. The calibration process is simple and short time-consuming, and the calibration accuracy is satisfied to requirement. After compensating for the main centrifuge errors, the 16-position method will further increase the accuracy of an inertial navigation system.