Multi-Node Transfer Alignment Based on Mechanics Modeling for Airborne DPOS

This paper deals with the problem of multi-node transfer alignment estimation of airborne distributed position and orientation system (DPOS), and its aim is to achieve the motion parameters for all sub-nodes as high precision as possible by using the main system. The complicated aircraft deformation, especially the wing's flexure, will seriously decrease the accuracy of transfer alignment. Usually, the deformation between the main node and each sub-node is idealized as an independent Markov process. In fact, these deformations are interrelated at a certain moment. To solve the mentioned problem, a multi-node transfer alignment method based on mechanics modeling is proposed in this paper. In this method, the elastic mechanics theory is used to build a unified kinematic equation of the wing to describe the flexible deformations of all sub-nodes, and then the transfer alignment is performed to obtain the motion parameters of each sub-node with inertial measurement units (IMU). Finally, the motion parameters of other sub-nodes without IMUs are obtained by the least squares fitting. The mathematical simulation and semi-physical simulation based on flight experiment show that the proposed method is not only effective but also provides us some new insights into the multi-node measurement of DPOS.