🤖 AI Summary
To address the challenge of long-term, high-precision localization for outdoor robots in GNSS-denied environments, this paper proposes a tightly coupled navigation framework integrating wheel odometry and IMU with GNSS. Leveraging an extended Kalman filter (EKF), we formulate a unified state vector to jointly estimate robot pose, sensor biases, and critical mounting parameters—including lever arm, misalignment angles, and wheel radius errors—enabling real-time online identification. Unlike conventional GNSS/INS or odometry-only fusion paradigms, our approach significantly mitigates pose drift during prolonged GNSS outages. Experimental results demonstrate superior positioning accuracy during GNSS outages compared to state-of-the-art multi-sensor fusion methods. The proposed modeling framework exhibits both robustness and practicality for real-world deployment, and the implementation code is publicly released.
📝 Abstract
A long-term accurate and robust localization system is essential for mobile robots to operate efficiently outdoors. Recent studies have shown the significant advantages of the wheel-mounted inertial measurement unit (Wheel-IMU)-based dead reckoning system. However, it still drifts over extended periods because of the absence of external correction signals. To achieve the goal of long-term accurate localization, we propose Wheel-GINS, a Global Navigation Satellite System (GNSS)/inertial navigation system (INS) integrated navigation system using a Wheel-IMU. Wheel-GINS fuses the GNSS position measurement with the Wheel-IMU via an extended Kalman filter to limit the long-term error drift and provide continuous state estimation when the GNSS signal is blocked. Considering the specificities of the GNSS/Wheel-IMU integration, we conduct detailed modeling and online estimation of the Wheel-IMU installation parameters, including the Wheel-IMU leverarm and mounting angle and the wheel radius error. Experimental results have shown that Wheel-GINS outperforms the traditional GNSS/Odometer/INS integrated navigation system during GNSS outages. At the same time, Wheel-GINS can effectively estimate the Wheel-IMU installation parameters online and, consequently, improve the localization accuracy and practicality of the system. The source code of our implementation is publicly available (https://github.com/i2Nav-WHU/Wheel-GINS).