公开(公告)号：US20170337749A1

公开(公告)日：2017-11-23

申请号：US15597366

申请日：2017-05-17

Applicant: Google Inc.

Inventor： Esha Nerurkar ,  Sheng Zhao

IPC: G06T19/20 ,  G06T17/05

CPC classification number: G06T19/20 ,  G06F3/011 ,  G06F3/017 ,  G06F3/038 ,  G06T17/05

Abstract: An electronic device detects and recovers from fault conditions while tracking its motion and building a map of its environment. A front-end motion tracking module detects fault conditions while tracking motion over time and provides mapping data to a back-end mapping module. The front-end motion tracking module indicates to the back-end mapping module when a fault condition has been detected and when the fault condition is no longer detected. The back-end mapping module generates maps from the mapping data and merges the maps to build a three-dimensional representation of the environment. The back-end mapping module buffers or discards any mapping data received from the front-end motion tracking module during the existence of a fault condition. The back-end mapping module merges the maps generated based on mapping data received before and after the fault condition and adds the merged maps to the three-dimensional representation of the environment.

公开(公告)号：US20170336511A1

公开(公告)日：2017-11-23

申请号：US15595617

申请日：2017-05-15

Applicant: Google Inc.

Inventor： Esha Nerurkar ,  Simon Lynen ,  Sheng Zhao

IPC: G01S17/89 ,  H04N13/02 ,  G06T7/55 ,  H04N13/00 ,  G01S7/481

Abstract: An electronic device tracks its motion in an environment while building a three-dimensional visual representation of the environment that is used to correct drift in the tracked motion. A motion tracking module estimates poses of the electronic device based on feature descriptors corresponding to the visual appearance of spatial features of objects in the environment. A mapping module builds a three-dimensional visual representation of the environment based on a stored plurality of maps, and feature descriptors and estimated device poses received from the motion tracking module. The mapping module provides the three-dimensional visual representation of the environment to a localization module, which identifies correspondences between stored and observed feature descriptors. The localization module performs a loop closure by minimizing the discrepancies between matching feature descriptors to compute a localized pose. The localized pose corrects drift in the estimated pose generated by the motion tracking module.