Multi-Robot Bearing-only Pose Estimation via Angle Rigidity
This work addresses the problem of pose estimation for multi-robot systems in three-dimensional space when no prior orientation information is available. The paper proposes a distributed bearing-only estimation algorithm that relies solely on bearing measurements and their time derivatives expressed in each robot’s body-fixed frame. By introducing angular rigidity—a novel relaxation of the conventional bearing rigidity condition—the method simultaneously estimates both positions and orientations in SO(3) without requiring any known initial headings. This constitutes the first distributed bearing-only pose estimation approach in 3D that operates without prior orientation knowledge. Theoretical analysis establishes local exponential stability of the estimation error dynamics, and simulation results demonstrate the algorithm’s effectiveness and practicality under realistic conditions.