3.6 F. Localization Mode 定位模式

3.6.1 paragraph

We incorporate a Localization Mode which can be useful for lightweight long-term localization in well mapped areas, as long as there are not significant changes in the environment.

ORB-SLAM2包括一个定位模式，该模式适用于轻量级以及在地图已知情况下长期运行，只要那个环境没有发生剧烈变化。

In this mode the Local Mapping and Loop Closing threads are deactivated and the camera is continuously localized by the Tracking using relocalization if needed.

在该模式中，局部建图和回环检测的线程中是停用的，并且这个相机始终都是在通过追踪进行重定位。

In this mode the tracking leverages visual odometry matches and matches to map points.

在这个模式下，追踪模块使用视觉里程计进行匹配图像的点云。

Visual odometry matches are matches between ORB in the current frame and 3D points created in the previous frame from the stereo/depth information.

视觉里程计匹配在当前帧的ORB算子和由双目或者深度相机收集的3D点云。

These matches make the localization robust to unmapped regions, but drift can be accumulated.

这些匹配使得在没有地图的区域也能够精确重新定位，但是漂移将会被累加。

Map point matches ensure drift-free localization to the existing map.

地图点云匹配要确保在一个已经存在的地图当中零漂移定位，

This mode is demonstrated in the accompanying video.

这个模型在附带的video当中会显示。