Glossary
This glossary provides definitions for key technical terms used throughout the textbook. Terms are organized alphabetically for easy reference.
This glossary serves as the single source of truth for terminology consistency across all 16 chapters, as mandated by Constitution Principle III (Consistency & Standards).
A
Action (ROS 2) : A communication pattern in ROS 2 for long-running tasks that provide feedback and can be preempted. Used for tasks like navigation, manipulation, or complex behaviors.
Actuator : A component that converts energy into motion, such as motors or servos that move robot joints.
APA Citation : American Psychological Association citation format used for all references in this textbook to official documentation.
C
Costmap : A grid-based representation of the environment used for navigation, showing obstacles and free space. Can be static (from a map) or dynamic (from sensors).
D
DDS (Data Distribution Service) : The middleware used by ROS 2 for publish-subscribe communication, providing real-time data exchange.
Digital Twin : A virtual replica of a physical robot used for testing, validation, and development in simulation before deployment to hardware.
Domain Randomization : A technique for improving sim-to-real transfer by varying simulation parameters (lighting, textures, friction) to train robust policies.
G
Gazebo : An open-source 3D robotics simulator with physics engines, sensor simulation, and ROS 2 integration.
I
Isaac Sim : NVIDIA's GPU-accelerated robotics simulator built on Omniverse, featuring PhysX 5 physics and RTX ray tracing.
IMU (Inertial Measurement Unit) : A sensor that measures acceleration and angular velocity, used for robot orientation and motion tracking.
J
Joint : A connection between robot links that allows motion. Common types: revolute (rotational), prismatic (linear), and fixed.
L
LiDAR (Light Detection and Ranging) : A sensor that uses laser pulses to measure distances and create 3D point clouds of the environment.
LLM (Large Language Model) : An AI model trained on text data, used in robotics for high-level task planning and natural language understanding.
M
MDX : Markdown with JSX support, allowing React components to be embedded in Markdown files. Used for interactive content in this textbook.
Mermaid.js : A text-based diagramming tool used to create flowcharts and architecture diagrams in this textbook.
N
Nav2 : The navigation stack for ROS 2, providing global planning, local planning, costmaps, and behavior trees for robot navigation.
Node (ROS 2) : An independent process that performs a specific task (e.g., sensor reading, motor control, planning). Nodes communicate via topics, services, and actions.
P
PhysX : NVIDIA's physics engine used in Isaac Sim for realistic simulation of rigid body dynamics, collisions, and contacts.
Prism : A syntax highlighting library used in Docusaurus to display code examples with proper formatting.
Q
QoS (Quality of Service) : Policies in ROS 2 that control message delivery reliability, durability, and history for robust communication.
R
ROS 2 (Robot Operating System 2) : An open-source framework for robotics development, providing tools for communication, device drivers, libraries, and visualization.
ROS 2 Humble : A Long-Term Support (LTS) release of ROS 2 for Ubuntu 22.04, supported until 2027.
RTX Ray Tracing : NVIDIA's real-time ray tracing technology used in Isaac Sim for photorealistic rendering.
S
SDF (Simulation Description Format) : An XML format for describing robot models, sensors, and environments in Gazebo simulation.
Service (ROS 2) : A synchronous request-response communication pattern in ROS 2, used for one-off queries or commands.
Sim-to-Real Transfer : The process of deploying policies, controllers, or behaviors trained in simulation to real-world hardware.
T
Topic (ROS 2) : An asynchronous, many-to-many communication channel in ROS 2 for streaming data (e.g., sensor readings, state updates).
U
Ubuntu 22.04 : The Long-Term Support (LTS) Linux distribution used as the primary platform for this textbook.
URDF (Unified Robot Description Format) : An XML format for describing robot kinematics, geometry, and dynamics in ROS 2.
V
VLA (Vision-Language-Action) : An AI approach that integrates visual perception, natural language understanding, and robot action execution.
VSLAM (Visual Simultaneous Localization and Mapping) : A technique for building maps and localizing robots using only camera images, without external markers.
W
Workspace (ROS 2)
: A directory containing ROS 2 packages, organized into src/, build/, install/, and log/ subdirectories.
Adding New Terms
When you encounter unfamiliar terminology in the chapters, refer back to this glossary. Terms are introduced when first used and linked to this glossary for quick reference.
Use your browser's search function (Ctrl+F or Cmd+F) to quickly find specific terms in this glossary.