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Geometric Reasoning

Overview

The internal representation of the state of the world that robot lives in is called the robot's belief state. It includes the knowledge about the objects in robot's environment, e.g. current pose of an object or its dynamic state such as if it is stable or is currently in motion, and about the robot's internal state, such as the current configuration of its arms or its location in the world map.

CRAM uses OpenGL for visualizing the belief state, the Bullet physics engine for acquiring physics knowledge about the world and OpenGL offscrean rendering for giving the robot visual information about the world in the virtual environment.

The belief state representation used for geometric reasoning is built upon the representation of the world used in the Bullet physics engine. Whereas in Bullet the objects are just a set of meshes with certain physical parameters assigned to them (such as mass, inertia etc.), in CRAM objects have additional semantic information associated with them to enable reasoning.