Dragonfly, our Visual SLAM technology, provides high level of accuracy.
The “drift” is the accumulated error. Typically the drift applies only for stereo-camera installations. The drift applies only to “unknown” environments, that means venues and spaces where Dragonfly has not been used before, and for which there is not yet an existing 3D map created by Dragonfly. For example, the first time you drive a forklift with a camera and Dragonfly installed, inside a warehouse, you will be exploring an unknown environment. The drift is expressed as a percentage: this number indicates the amount of accumulated error, and can be considered as the amount of meters of error for each 100 linear meters.
The drift, and the error for monocular cameras’ systems, are however automatically corrected by Dragonfly each time there is a loop-closing. This means that each time Dragonfly recognizes an area that has already been mapped, the loop closes, and Dragonfly corrects the location and the map is also updated. Loop-closings are extremely useful to improve the overall accuracy of the system, and it is strongly recommended to perform frequent loop-closings during the initial mapping, for both monocular and stereo cameras architecture.
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Linear Accuracy When navigating inside a known environment, therefore when Dragonfly re-locates the device inside a previously created map, the accuracy depends on the precision of the triangulation of known points (features). The linear accuracy, the radius of confidence (ROC), is typically 5-10 cm, and depends on several factors, including:
As an example, imagine a drone navigating inside a hangar that has already been “mapped” before: in this case, the ROC of the drone will be 5-10 cm.