Symmetric calibration method of pendulous Integrating Gyroscopic accelerometer on centrifuge

With increasing requirements for the accuracy of Pendulous Integrating Gyroscopic Accelerometer (PIGA), developing effective methods that can accurately calibrate nonlinear error parameters of PIGA is a necessity. In this paper, the symmetric position calibration method is proposed to calibrate the main nonlinear error coefficients of PIGA within integer precession periods on the centrifuge. Firstly, coordinate systems are established, and specific forces, as well as angular velocities of PIGA, are deduced. Then, the complete error calibration model of PIGA, including the high-order error terms, is established. Calibration methods in symmetric positions are proposed, while the closure errors are restrained by the reasonable design of the test time. The centrifuge experiments show that the influence of misalignments could be restrained by the proposed calibration method, but the angular velocity of the main axis should be monitored. Thus, the impact of centrifuge errors on the measurement accuracy of PIGA is effectively suppressed, thereby reducing output uncertainty of PIGA to 10−6 rad/s. The simulation results show that the order of calibration uncertainty of PIGA’s second-order error parameter is decreased from 10−6 to 10−7 and the order of calibration uncertainty of other nonlinear error term coefficients is lowered to less than 10−6. Finally, the calibration accuracy of PIGA reaches 1 × 10−7g/g.