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

摘要

Techniques that optimize performance of simultaneous localization and mapping (SLAM) processes for mobile devices, typically a mobile robot. In one embodiment, erroneous particles are introduced to the particle filtering process of localization. Monitoring the weights of the erroneous particles relative to the particles maintained for SLAM provides a verification that the robot is localized and detection that it is no longer localized. In another embodiment, cell-based grid mapping of a mobile robot's environment also monitors cells for changes in their probability of occupancy. Cells with a changing occupancy probability are marked as dynamic and updating of such cells to the map is suspended or modified until their individual occupancy probabilities have stabilized. In another embodiment, mapping is suspended when it is determined that the device is acquiring data regarding its physical environment in such a way that use of the data for mapping will incorporate distortions into the map, as for example when the robotic device is tilted.

主权项

1. A system for identifying and marking dynamic areas of a map of a physical environment of a mobile device, the system comprising:
a. a data acquisition system that generates data identifying the mobile device's physical environment; and b. a processing apparatus, responsive to the data acquisition system, to map or model the mobile device's physical environment and the data acquisition system's location within the mobile device's physical environment in a cell-based grid in which cells are assigned probabilities indicating certainty about whether the physical space corresponding to a cell is occupied by an object or contains empty space; c. wherein the processing apparatus includes apparatus that:
i. assigns and updates probabilities to each cell within the grid map from the data generated by the data acquisition system;ii. determines if changes in a cell's probability of occupancy indicate that a cell currently identified as empty has become occupied or a cell currently identified as occupied has become empty;iii. marks each cell so as not to be updated with regard to its probability of occupancy while said probability is changing; and d. wherein the processing apparatus further includes apparatus that monitors sudden changes in consecutive cells to determine whether a tilt event has occurred.