Distributed UWB-Aided Cooperative Positioning with Height Constraints for Multi-AGV Systems in Gnss Challenged Conditions

This paper proposes a distributed cooperative positioning (CP) framework for autonomous ground vehicle (AGV) clusters operating in Global Navigation Satellite System (GNSS) challenged conditions. Each AGV performs local state estimation using GNSS/Inertial Measurement Unit (IMU) measurements and exchanges only position and covariance information with neighboring nodes to minimize communication load. Inter-node Ultra Wide Band (UWB) ranging and a height constraint are incorporated into a distributed Kalman filter to enhance network observability and ensure stable positioning. Real-world experiments with a multi-AGV platform demonstrate that the proposed framework achieves superior positioning accuracy and robustness compared with the centralized method. Moreover, the inclusion of the height constraint effectively improves local geometric configuration and reduces Geometric Dilution Precision (GDOP), leading to more consistent and reliable positioning performance for GNSS-limited nodes within the cooperative network.