A new high-accuracy transfer alignment method for distributed INS on moving base

The flexible deformation and lever-arm effect are the key factors restricting the transfer alignment accuracy in distributed inertial navigation system (INS). The traditional compensation method based on empirical model may lead to a decrease in transfer alignment accuracy and even filter divergence due to model mismatch. Therefore, a high-accuracy transfer alignment method independent of empirical model is proposed. Firstly, the rough values of flexible deformation/lever-arm are directly calculated using the angular velocities/specific forces measured by master/slave inertial sensors. Then, the error state models of flexible deformation/lever-arm are derived, and the measurement model is established based on the geometric relationship between flexible deformation and dynamic lever-arm. Furthermore, the optimal estimation algorithm is used to accurately estimate and correct the calculation error of flexible deformation/lever-arm in real-time. The simulation and experiment results show that the proposed method can accurately compensate the complex flexible deformation and lever-arm effect, thereby achieving high-accuracy transfer alignment.