Concept

There exist various frames that are needed to obtain the robot's global pose (pose within in the global frame):

Name	Description
`global`	The "world" frame
`map`	During mapping, the robot does not have knowledge about the world but creates a local map (with `map` as root frame). All map features (e.g. point clouds, occupancy grids, ...) are linked to this frame.
`odom`	The odometry as an integration of the robot's velocity.
`robot`	The robot's root frame

frames

For each transformation between frames, there exist individual components:

Involved Frames	Description
`global->map`	Map registration: given a scene (objects with known poses, e.g. walls, ...), this component obtains a static transformation between a the scene and the map.
`map->odom`	Localization The localization component computes the transformation `map->robot` and performs map corrections by updating `map->odom`.
`odom->robot`	Odometry

Memory Design

Within the core segment, each robot has its own provider segment (here: Armar6). Within the provider segment, entities describe the transformations between the frames (Global,Map -> global->map).

Localization

Using the Localization Memory

See armarx::armem::client::robot_state::localization (include RobotAPI/libraries/armem_robot_localization/).

There exist two classes:

armarx::armem::client::robot_state::localization::TransformWriter to send transformations to memory
armarx::armem::client::robot_state::localization::TransformReader to obtain transformations between any of the frames; can also be used to obtain the "robot's global pose"

For an example, see RobotComponents/components/carographer_mapping_and_localization (currently branch feature/cartographer_integration)