Cooperative positioning for low-cost close formation flight based on relative estimation and belief propagation

Cooperative Positioning (CP) is considered to be a promising method for close formation flight, which can fully exploit the navigation information in a network. This work proposes a new CP framework based on relative position estimation and optimized belief propagation (BP), aiming to enhance the absolute positioning accuracy for low-cost UAVs. Relative estimation is used to augment the BP estimation, which can fully exploit the onboard sensors. For BP, it is widely used as a CP estimator. This work proposes an optimized BP based on vectorized message passing and message evaluation, which can make an effective balance between computational load and estimation accuracy. Simulation results show that the proposed CP framework has better estimation accuracy than traditional CP methods, and has lower computational load than the best existing non-parametric BP (NBP) method with equivalent accuracy. (C) 2020 Elsevier Masson SAS. All rights reserved.