Invariant Extended Kalman Filtering with Partial Orientation Measurement Integration: Theoretical Derivations and Application to Autonomous Surface Vessels
For autonomous surface vessels operating in open ocean, this work addresses the challenge of using partial orientation measurements in InEKF, but the results are incremental as they only demonstrate comparable performance to existing methods.
The paper proposes an Invariant Extended Kalman Filter (InEKF) framework that integrates partial orientation measurements (roll and pitch from horizon sensing) for autonomous surface vessels, achieving accurate state estimation in open ocean environments. Comparative analysis shows the proposed method is robust and effective, though no specific numerical improvements are provided.
Autonomous surface vessels (ASVs) are increasingly vital for marine science, offering robust platforms for underwater mapping and inspection. Accurate state estimation, particularly of vehicle pose, is paramount for precise seafloor mapping, as even small surface deviations can have significant consequences when sensing the seafloor below. To address this challenge, we propose an Invariant Extended Kalman Filter (InEKF) framework designed to integrate partial orientation measurements. While conventional estimation often relies on relative position measurements to fixed landmarks, open ocean ASVs primarily observe a receding horizon. We leverage forward-facing monocular cameras to estimate roll and pitch with respect to this horizon, which provides yaw-ambiguous partial orientation information. To effectively utilize these measurements within the InEKF, we introduce a novel framework for incorporating such partial orientation data. This approach contrasts with traditional InEKF implementations that assume full orientation measurements and is particularly relevant for vehicles operating in a \say{semi-planar} environment, where the attitude is characterized by a dominant yaw rotation with limited roll and pitch variations. This paper details the developed InEKF framework; its integration with horizon-based roll/pitch observations and dual-antenna GPS heading measurements for ASV state estimation; and provides a comparative analysis against the InEKF using full orientation and a Multiplicative EKF (MEKF). Our results demonstrate the efficacy and robustness of the proposed partial orientation measurements for accurate ASV state estimation in open ocean environments.