Systems and methods for using multiple hypotheses in a visual simultaneous localization and mapping system
The invention is related to methods and apparatus that use a visual sensor and dead reckoning sensors to process Simultaneous Localization and Mapping (SLAM). These techniques can be used in robot navigation. Advantageously, such visual techniques can be used to autonomously generate and update a map. Unlike with laser rangefinders, the visual techniques are economically practical in a wide range of applications and can be used in relatively dynamic environments, such as environments in which people move. One embodiment further advantageously uses multiple particles to maintain multiple hypotheses with respect to localization and mapping. Further advantageously, one embodiment maintains the particles in a relatively computationally-efficient manner, thereby permitting the SLAM processes to be performed in software using relatively inexpensive microprocessor-based computer systems.
1. A method of autonomous localization and mapping, the method comprising:
visually observing an environment via a visual sensor;
maintaining a map of landmarks in a data store, where the map of landmarks is based at least in part on visual observations of the environment;
receiving data from a dead reckoning sensor, where data from the dead reckoning sensor relates to movement of the visual sensor within the environment;
using data from the dead reckoning sensor and a prior pose estimate to predict a new device pose in a global reference frame at least partly in response to a determination that a known landmark has not been encountered; and
using data from the visual sensor to predict a new device pose in the global reference frame at least partly in response to a determination that a known landmark has been recognized, where the new device pose estimate is based at least in part on a previous pose estimate associated with the known landmark and using the visual sensor data to update the map;
wherein the data from the visual sensor comprises 2D image coordinates of features associated with the recognized landmark.
2. The method as defined in claim 1 , further comprising using the autonomous localization and mapping in a mobile robot.
3. The method as defined in claim 1 , wherein the map comprises one or more maps.
4. The method as defined in claim 1 , wherein the visual sensor corresponds to one or more cameras.
5. The method as defined in claim 1 , wherein the dead reckoning sensor corresponds to at least one of an odometer or a pedometer.