旋转式惯性导航系统的三次序整圈旋转自对准方法

To address the issue that deterministic errors in two-position alignment of rotational inertial navigation systems exceed expectations, a theoretical analysis of heading alignment errors is conducted based on the rate of velocity error variation, and a three-stage full-circle rotation alignment scheme is proposed. By establishing a model for the equivalent northward accelerometer error variation rate under time-varying conditions, it is revealed that celestial-axis angular velocity measurement error constitutes a non-negligible error source for heading alignment. Comprehensive error analysis has been conducted for the commonly used two-position scheme and the forward-backward full-circle rotation scheme. The forward-backward rotation scheme can effectively eliminate accelerometer lever arm errors and non-orthogonality errors while suppressing gyro mounting angle errors, though it amplifies gyro scale factor errors; whereas the three-stage full-circle rotation scheme combines the advantages of both approaches. The superiority of the proposed scheme is verified using a rotary fiber optic inertial navigation system. The heading effect error and the comprehensive alignment error are reduced from 25.74″ and 23.25″ in the two-position scheme to 4.86″ and 14.74″ in the three-stage full-circle rotation scheme, respectively.