Glossary#

ROS: Robot Operating System: middleware and tools for communicating between robot software components. ROS 1 and ROS 2 are different implementations.
Node: A participant in the ROS communication graph, such as a camera publisher or GTA command server.
Topic: A named message stream. Publishers send messages; subscribers receive them.
Action: A goal-based ROS interface with acknowledgement, progress/result, and cancellation. GTA’s ROS 2 gripper uses an action.
QoS: Quality of Service: ROS 2 communication policies such as reliability and queue depth. Incompatible policies can prevent messages from arriving.
RTDE: Real-Time Data Exchange, used here through UR RTDE libraries to read the UR5e’s state and send motion/force-control commands.
TCP: Tool Center Point: the tool pose configured in the robot controller. GTA can define an additional tool point relative to that reported pose; it does not change the robot’s TCP configuration.
Pose: Position and orientation together. GTA’s robot-state pose contains three position values in metres and a three-value rotation vector in radians.
Rotation vector: An axis-angle representation: direction gives the rotation axis and length gives the angle in radians. It is not roll/pitch/yaw.
Frame: A coordinate system in which positions and directions are expressed. The robot base, reported TCP, camera, and attached object may have different frames; transforms relate them.
Keypoint: A named geometric point used by a controller, such as the center of a cube’s top face. Image keypoints must be mapped to 3D before robot execution.
Grounding: Associating the plan’s named keypoints with locations in a particular scene. A plan can remain useful while its old grounding becomes invalid.
Controller: A function-like component that computes an error packet for a geometric, force, or gripper objective. GTA projects ordered packets into commands.
Priority: The order in which controllers claim constrained directions. Lower-priority positional errors contribute only in the remaining translational space.
Point cloud: A collection of 3D points. An organized, image-aligned cloud retains a known point for each image pixel; arbitrary unordered clouds do not.
Checkpoint: A saved plan, context, history, and copied artifacts. Loading creates an independent working copy.
Session: A mutable library working copy with its own workspace and execution records.
Requery: Grounding the saved keypoint definitions again for a fresh scene image. Annotation feedback instead operates on the currently displayed image.
DMP: Dynamic Movement Primitive: a parameterized trajectory representation. GTA supplies a planar spiral controller with a bundled learned model.