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Vision Robotics Technology
Localization
Keeping track of the robots position (pose) is called "localization" and is critically important. We are using several different techniques to calculate this position with tradeoffs involving processing speed and accuracy.
- Landmark Localization - Landmarks such as lines, corners and other markers are used to triangulate the controller's position. The landmarks come from the stereo image analysis and are compared with a stored database of landmarks. The stored database is built concurrently during the exploration phase and so the current set of landmarks are compared with previous landmarks seen.
- Grid Based Localization - Grid based localization uses "objects" found in the current image stereo data to align with the currently stored 3-D grid data.
- Cord Based Localization - For robots with a power cord, the cord provides a landmark and can be used for localization because it is generally visible and fairly static.
There is a strong interdependence between the current pose and the map/environment information currently collected which means that errors in the map will cause errors in localization and localization errors will cause errors in the map. To reduce this error, recursive localization and re-mapping of the environmental data (3-D grid and landmarks) is done.
In addition, localization can combine information from other sensors, e.g. GPS, to calculate the current pose.
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