Synchronous Observer Design for Landmark-Inertial SLAM with Magnetometer and Intermittent GNSS Measurements
This addresses a fundamental observability limitation in SLAM for robotics, though it appears incremental as it builds on existing LI-SLAM methods with sensor additions.
The paper tackles the unobservability of robot and landmark positions in inertial frame and yaw in Landmark-Inertial SLAM by proposing a nonlinear observer that incorporates intermittent GNSS and magnetometer measurements, achieving almost-global asymptotic and local exponential stability in simulations.
In Landmark-Inertial Simultaneous Localisation and Mapping (LI-SLAM), the positions of landmarks in the environment and the robot's pose relative to these landmarks are estimated using landmark position measurements, and measurements from the Inertial Measurement Unit (IMU). However, the robot and landmark positions in the inertial frame, and the yaw of the robot, are not observable in LI-SLAM. This paper proposes a nonlinear observer for LI-SLAM that overcomes the observability constraints with the addition of intermittent GNSS position and magnetometer measurements. The full-state error dynamics of the proposed observer is shown to be both almost-globally asymptotically stable and locally exponentially stable, and this is validated using simulations.