Method and apparatus for simultaneous localization and mapping of mobile robot environment

A method for controlling movement of a mobile robot, the method comprising:

• obtaining position data of objects relative to the mobile robot;
• obtaining pose data of the mobile robot;
• generating, from the position data and the pose data, using a SLAM algorithm, map data identifying the mobile robot's physical environment;
• creating a map of the mobile robot's physical environment and recording the location of the mobile robot within the mobile robot's physical environment in response to the map data;
• determining whether the mobile robot has become delocalized;
• suspending the generating of the map data while the mobile robot is delocalized;
• and
• resuming the generating of map data when the mobile robot has become re-localized, with a determination that the mobile robot has become re-localized including hysteresis that provides for a period of time during which the generating of map data is stable.

A mobile device tracking system for a mobile device in its physical environment comprising:

• a spatial sensor mounted on the mobile device and configured to scan the physical environment;
• a map generator configured to generate and update a map from the spatial data, the map including the current position of the mobile device;
• and
• a delocalization detector configured to generate a current estimate by estimating the current position within said map by generating position particles indicating at least one of position and orientation of the mobile device within its physical environment, the delocalization detector being further configured to generate and iteratively maintain a data set of said position particles to track a changing position of the mobile device within its physical environment, the delocalization detector including:
• i. a particle weight assignor that assigns a weight to each position particle, the particle weight being a relative measure of the likelihood that the position particle accurately represents the current position with respect to other particles;
• ii. an erroneous particle generator that introduces erroneous particles having weights that are uniformly low with respect to the weights of the position particles;
• and
• iii. a particle weight comparator that compares the weights of the erroneous particles and the weights of the position particles and determines that the mobile device has become delocalized when a substantial number of erroneous particles have weights that are no longer uniformly low with respect to the weights of the position particles.