Glossary of Robotic Systems Terms and Definitions

Precise terminology is foundational to robotic systems engineering, procurement, safety compliance, and policy development. This glossary defines the core vocabulary used across industrial, collaborative, autonomous, medical, and service robotics — drawing on definitions established by the International Organization for Standardization (ISO), the International Federation of Robotics (IFR), the National Institute of Standards and Technology (NIST), and the Association for Advancing Automation (A3). The terms collected here appear throughout the robotic systems discipline and are essential reference material for engineers, integrators, regulators, and procurement professionals navigating this field.

Definition and scope

A glossary of robotic systems terms serves a stricter function than a general technology dictionary: it establishes the precise definitional boundaries that govern standards applicability, safety classification, regulatory scope, and system integration decisions. When the same word carries different meanings across ISO standards, OSHA guidance, and vendor literature, operational and legal consequences follow.

The scope of this glossary encompasses five primary domains of robotic systems vocabulary:

Mechanical and structural terms — robot configurations, kinematic chains, degrees of freedom, and workspace geometry
Control and software terms — operating systems, programming paradigms, autonomy levels, and feedback architectures
Perception and sensing terms — sensor modalities, fusion methods, and environmental representation
Safety and regulatory terms — risk categories, safety-rated functions, collaborative operation modes, and standards designations
Application and deployment terms — integration models, payload classifications, and operational domain descriptors

For the regulatory context for robotic systems, understanding these definitional boundaries is not optional — ISO 10218-1 and ISO 10218-2 use specific defined terms to determine which safety requirements apply to a given installation.

How it works

Robotic systems terminology functions as a structured hierarchy in which foundational terms underpin the definitions of more complex concepts. The definitions below are organized alphabetically within thematic clusters, with source attribution where definitions derive from named standards bodies.

Mechanical and structural terms

Articulated robot — A robot whose arm has rotary joints connecting at least 3 axes of motion. ISO 8373:2012 classifies articulated robots as a distinct configuration type, separate from Cartesian, cylindrical, SCARA, and parallel configurations.

Cartesian robot — A robot that moves along three mutually perpendicular linear axes (X, Y, Z), sometimes called a gantry robot. Cartesian robots offer high positional accuracy and are commonly applied in pick-and-place and CNC-style operations.

Collaborative robot (cobot) — Per ISO/TS 15066:2016, a robot designed to work in direct interaction with a human within a defined collaborative workspace. The standard defines 4 collaborative operation modes: safety-rated monitored stop, hand guiding, speed and separation monitoring, and power and force limiting.

Degree of freedom (DOF) — A single independent axis of motion. A standard 6-DOF industrial robot arm can position and orient its end effector at any point within its reachable workspace. Additional DOFs, such as a 7th axis for elbow articulation, extend dexterity.

End effector — The device mounted at the end of a robot arm that interacts directly with the environment. End effectors include grippers, welding torches, suction cups, cutting tools, and sensors.

Payload capacity — The maximum mass a robot can handle at its end effector while maintaining specified accuracy. Payload ratings range from sub-kilogram for precision electronics assembly robots to over 1,000 kg for heavy industrial units.

Reach envelope (workspace) — The full volume of space accessible by a robot's end effector. ISO 8373:2012 distinguishes maximum space, restricted space, and operating space as nested subsets.

Repeatability — The ability of a robot to return to a previously taught position under the same conditions. Industrial robots typically achieve repeatability within ±0.02 mm to ±0.1 mm, a metric distinct from absolute accuracy.

Control and software terms

Autonomous mobile robot (AMR) — A robot that navigates independently using onboard sensors and computational intelligence rather than fixed guiding infrastructure. AMRs differ from automated guided vehicles (AGVs), which follow predefined physical or magnetic paths.

Automated guided vehicle (AGV) — A mobile robot that follows a fixed path defined by magnetic tape, reflective markers, wire, or pre-mapped laser paths. AGVs operate within constrained routes and require physical or mapped infrastructure changes to alter paths.

Kinematic model — A mathematical representation of a robot's mechanical structure that maps joint positions to end-effector position and orientation. Forward kinematics computes end-effector pose from joint states; inverse kinematics computes joint states from a desired end-effector pose.

Robot Operating System (ROS) — An open-source middleware framework that provides hardware abstraction, device drivers, inter-process communication, and tools for robotic software development. ROS 2, maintained by Open Robotics, is the production-supported successor addressing real-time and security requirements absent in ROS 1.

Teach pendant — A handheld device used to manually guide or program a robot by moving it through target positions. Positions recorded via teach pendant are stored as waypoints in the robot's controller.

Perception and sensing terms

LiDAR (Light Detection and Ranging) — A sensor that emits laser pulses and measures return times to generate precise 3D point clouds of the surrounding environment. LiDAR is a primary navigation sensor in AMRs and autonomous vehicles, with range capabilities typically spanning 0.1 m to over 200 m depending on sensor class.

Sensor fusion — The process of combining data from 2 or more sensor modalities — such as LiDAR, cameras, and inertial measurement units — to produce a unified environmental representation more reliable than any single sensor source.

SLAM (Simultaneous Localization and Mapping) — A computational process by which a robot constructs a map of an unknown environment while simultaneously tracking its own position within that map. SLAM is foundational to AMR navigation and is actively researched at NIST's Intelligent Systems Division.

Safety and regulatory terms

Functional safety — The aspect of overall safety that depends on a system responding correctly to its inputs. Functional safety in robotic systems is governed by IEC 62061 and ISO 13849-1, which define Safety Integrity Levels (SIL) and Performance Levels (PL) respectively.

Performance Level (PL) — A discrete level (a through e) used to specify the ability of safety-related parts of a control system to perform a safety function under foreseeable conditions, as defined in ISO 13849-1.

Risk assessment — A structured process for identifying hazards, estimating associated risks, and evaluating risk reduction measures. ISO 12100:2010 defines the risk assessment and risk reduction methodology applicable to machinery including robots.

Safety-rated monitored stop — One of the 4 collaborative operation modes in ISO/TS 15066:2016, in which a robot halts when a person enters the collaborative workspace and resumes only after the person exits and a deliberate restart is executed.

Application and deployment terms

End-of-arm tooling (EOAT) — A broader term encompassing all devices attached to a robot's wrist or flange, including end effectors, force-torque sensors, vision systems, and quick-change adapters.

Integration — The process of combining a robot with surrounding systems — conveyors, PLCs, safety systems, vision systems, and facility networks — into a functional production cell. Integrators operate under ISO 10218-2, which governs robot system and integration safety requirements.

Uptime / duty cycle — The proportion of scheduled production time during which a robot is operational. High-availability industrial robots are engineered for duty cycles exceeding 95% across shifts spanning up to 24 hours per day.

Common scenarios

The definitional distinctions codified in this glossary become operationally critical in the following contexts:

Standards applicability determination — Whether ISO 10218-1 (robot manufacturer requirements) or ISO 10218-2 (integrator requirements) governs a specific installation depends on how the system is classified. Misclassifying a fixed industrial robot as a collaborative system creates a safety gap because the power and force limiting requirements of ISO/TS 15066 would not be applied.

Procurement and specification writing — Payload capacity, reach, repeatability, and IP rating (Ingress Protection per IEC 60529) must be specified using standardized terms to enable valid comparison across vendors. A specification provider "accuracy" without distinguishing repeatability from absolute accuracy will produce non-comparable bids.

Regulatory compliance documentation — OSHA 29 CFR 1910.217 governs mechanical power presses, and OSHA has issued voluntary guidelines for industrial robots (OSHA 3067). Accurate classification of a robotic system — whether it constitutes a collaborative installation or a traditional safeguarded cell — determines which guidance documents and risk reduction requirements apply. The full regulatory landscape is detailed in the regulatory context for robotic systems.

Cross-discipline communication — A facility's safety engineer, automation programmer, and procurement officer must share a common vocabulary. The A3 (Association for Advancing Automation) publishes terminology resources and supports the Robotic Industries Association standards committee to maintain consistency across the industry.

Decision boundaries

Several paired terms are frequently conflated in ways that produce technical or compliance errors. The following contrasts clarify where boundaries fall:

AMR vs. AGV — The critical distinction is navigation method. An AMR uses onboard intelligence and sensor-based mapping (SLAM) to navigate dynamically; an AGV follows a fixed infrastructure-defined path. This affects which safety standard applies: ISO 3691-4 governs industrial trucks including AGVs, while ISO 15695 and related standards address AMR-specific considerations.

Repeatability vs. absolute accuracy — Repeatability measures how consistently a robot returns to a