Experimental Comparison of Visual and Single-Receiver GPS Odometry
This provides an incremental improvement for practitioners in robotics by offering a more accurate alternative or complement to visual odometry.
The paper tackled the problem of mobile robot odometry by comparing visual odometry with a new single-receiver GPS odometry method, finding that the GPS method had a 75% lower drift rate over 1.8km of testing.
Mobile robots rely on odometry to navigate through areas where localization fails. Visual odometry (VO) is a common solution for obtaining robust and consistent relative motion estimates of the vehicle frame. Contrarily, Global Positioning System (GPS) measurements are typically used for absolute positioning and localization. However, when the constraint on absolute accuracy is relaxed, time-differenced carrier phase (TDCP) measurements can be used to find accurate relative position estimates with one single-frequency GPS receiver. This suggests practitioners may want to consider GPS odometry as an alternative or in combination with VO. We describe a robust method for single-receiver GPS odometry on an unmanned ground vehicle (UGV). We then present an experimental comparison of the two strategies on the same test trajectories. After 1.8km of testing, the results show our GPS odometry method has a 75% lower drift rate than a proven stereo VO method while maintaining a smooth error signal despite varying satellite availability.