Envire Rationale

Envire is a package for representing information on the environment. The rationale behind the development is to have a common way of holding any information related to the environment of the robot. The application of envire is mainly focused on navigation tasks for now, but could be extended to also include robot environment interaction for manipulation. The reasoning for having a common datastructure for representing the environment is to simplify the interchange of algorithms between applications.

Overview

The envire package is mainly made up of three types of objects:

• Maps representing information in a given reference frame. Maps can be 2d or 3d, sparse or dense. In principle envire also supports non-cartesian maps, although not much has been done so far in this area.

• Frames provide the spatial context for the maps. Each map can have a reference frame associated. All frames are organized in a tree structure. In this way for any two frames in this tree, there is a defined transformation between them.

• Operators perform operations on maps and take the frame association of the maps into account. Operators are stored in a graph structure, and can be chained to produce something like a processing pipelines for sensory input and post-processing of map data.

Envire also provides common services. All objects are stored in an environment, which supports serialization/deserialization. There is also handling for meta information associated with the individual elements. Further, there is an event system, which can be used for notification on changes in the structure of the environment. Envire also provides a vizkit plugin, with plugin modules for most of the map types.