An IMU-Aided Carrier-Phase Differential GPS Positioning System
This work addresses precise localization for land vehicles, but it appears incremental as it builds on existing GPS-IMU fusion methods with specific adaptations.
The authors tackled the problem of improving land vehicle navigation by tightly coupling an IMU and speedometer with carrier-phase differential GPS, using a Bayesian network to integrate measurements and adding pseudo measurements for vehicle constraints, resulting in a system that enhances positioning accuracy.
We consider the problem of carrier-phase differential GPS positioning for an land vehicle navigation system (LVNS), tightly coupled with an inertial measurement unit (IMU) and a speedometer. The primary focus is to apply Bayesian network to an IMU-aided GPS positioning system based on carrier-phase differential GPS. We describe the implementation details of the positioning system that integrates GPS measurements (i.e., pseudo-range, carrier-phase and doppler), IMU measurements, and speedometer measurements. We derive the linearized state process equation and the measurement equation for GPS and speedometer. To account for constraints of land vehicle, we add two more pseudo measurements to ensure the perpendicular velocities close to zero.