This collaborative robots glossary uses definitions from various sources to define terminology end users must know to effectively understand and use collaborative robot arms. The terms in the collaborative robots glossary cover many topics, including what collaborative robot arms are, how they move, how much they can lift, how safe they are, and important enabling technologies.

This glossary will be updated as new terms gain importance. If there are terms we should add to this glossary, let us know in the comments.

Acceleration	How quickly an axis can accelerate. Since this is a limiting factor a robot may not be able to reach its specified maximum speed for movements over a short distance or a complex path requiring frequent changes of direction.
Accuracy	How closely a robot can reach a commanded position. When the absolute position of the robot is measured and compared to the commanded position the error is a measure of accuracy. Accuracy can be improved with external sensing for example a vision system or Infra-Red. See robot calibration. Accuracy can vary with speed and position within the working envelope and with payload.
Actuator	A motor that translates control signals into mechanical movement. The control signals are usually electrical but may, more rarely, be pneumatic or hydraulic. The power supply may likewise be any of these. It is common for electrical control to be used to modulate a high-power pneumatic or hydraulic motor
Algorithm	A set of procedures used to solve a problem.
Artificial Intelligence (AI)	The simulation of human intelligence processes by machiness. These processes include learning (the acquisition of information and rules for using the information), reasoning (using the rules to reach approximate or definite conclusions), and self-correction.
Axis	The line about which a rotating body (such as a tool) turns.
Axis Acceleration	The maximum acceleration that a particular axis can attain while the robot is loaded with the suggested payload.

Ball Screw	A device for transforming rotary motion to linear, or vice versa, incorporating a threaded rod portion and a nut consisting of a cage holding many ball bearings.
Barrier	A physical means of separating persons from the restricted envelope.
Base	The platform which supports the manipulator arm.
Biomimetic	Mimicking life or natural biological systems.

Cobot	Slang term for collaborative robot.
Collaborative Robot	Robot specifically designed for direct interaction with a human within a defined collaborative workspace.
Collaborative Workspace	Safeguarded space where the robot and a human can perform tasks simultaneously during automatic operatio
Collaborative Operation	State in which purpose designed robots can safety work in direct cooperation with a human within a defined workspace
Collision Sensor	A sensor that detects and informs the controller to stop the robot prior to or during a crash. Other terms for this device include crash protection device, robot safety joint, and robotic clutch, among others.
Control Command	An instruction fed to the robot by means of the human-to-machine input device. This command is received by the robot’s controller system and is interpreted. The proper instruction is fed to the robot’s actuators, which enable it to react to the initial command.
Control Device	An instrument that allows a person to have control over a robot or automated system for times such as startup or an emergency.
Control Program	The set of control instructions that defines the capabilities, actions and responses of the robot system. This program is usually not intended to be modified by the user.

Degrees of Freedom (DOF)	The specific, defined modes in which a mechanical device or system can move. The term is widely used to define the motion capabilities of robots. A robotic joint is equal to one degree of freedom.
Drive Power	The source of supplying energy to the robot actuators to produce motion.

Emergency Stop	A method using hardware-based components that overrides all other robot controls and removes drive power from the robot actuators to bring all moving parts to a stop.
Encoder	A feedback device in the robot manipulator arm that provides current position (and orientation of the arm) data to the controller. A beam of light passes through a rotating code disk that contains a precise pattern of opaque and transparent segments on its surface. Light that is transmitted through the disk strikes photo-detectors, which convert the light pattern to electrical signals.
End of Arm Tooling (End Effector)	An end of arm tool is the device at the end of a robotic arm, designed to interact with the environment. The exact nature of this device depends on the application of the robot.

Feedback	A signal from the robot about conditions as they actually exist, rather than as the computer has directed them to exist.
Force Control	A method of error detection in which the force exerted on the end-effector is sensed and fed back to the controller.
Force-limited Robots	A robot with a built-in force torque sensor that detects impact and abnormal forces. The sensor stops the robot when they are triggered. They tend to have rounder shapes, cushioned shells to absorb shock, all making them less harmful to humans
Force Torque Sensor	force torque sensor The sensors that measure the amount of force and torque exerted by the mechanical hand along three hand-referenced orthogonal directions and applied around a point ahead and away from the sensors.

Gripper	A gripper is a type of end of arm tool that enables a cobot to hold and manipulate an object. Many styles and sizes of grippers exist so that the correct model can be selected for the application.
Grip Force	The grip force is the amount of force the end effector applies on an object to hold it as the robot moves. Grip force is not the same as payload.

Home Position

A known and fixed location on the basic coordinate axis of the manipulator where it comes to rest, or to an indicated zero position for each axis. This position is unique for each model of manipulator.

Intelligent Robot	A robot that can be programmed to make performance choices contingent on sensory inputs with little or no help from human intervention.
Internal Sensor	A sensor within the collaborative robot arm that sends information on motion to a control unit.
Inverse Kinematics	Determination of a joint’s overall change in position based on restrictions on the end-effector’s motion of a robot.

Limiting Device

A device that restricts the maximum envelope (space) by stopping or causing to stop all robot motion and is independent of the control program and the application programs.

Offline Programming

Developing robot programs without requiring the use of the robot itself. The program is loaded into the robot’s controller for subsequent automatic action of the manipulator. The advantages of offline programming are reduction of robot downtime; removal of programmer from potentially hazardous environments; a single programming system for a variety of robots; integration with existing computer aided design/computer-assisted manufacturing systems; simplification of complex tasks, and verification of robot programs prior to execution.

Online Programming

The use of a teach pendant for teach programming, which directs the controller in positioning the robot and interacting with auxiliary equipment. It is normally used for point-to-point motion and controlled path motion robots, and can be used in conjunction with off-line programming to provide accurate trajectory data.

Payload Capacity	The maximum weight that can be applied to the robot arm without sacrifice of any of the applicable published specifications of the robot
Palletizing	The process of placing parts in different positions on a pallet.
Pick-and-Place Robot	A category of robot used to pick parts and place them down somewhere else.
Position Sensor	Sensor detecting the position of the rotor relative to the state of the actuator. In general, one of two sensor types is used: the pulse coder type, also known as digital encoder or the resolver type.

Reach	The distance a robot’s end-effector can reach in at least one orientation.
Repeatability	The ability for the robot to return to a programmed position. This is not the same as accuracy. It may be that when told to go to a certain X-Y-Z position that it gets only to within 1 mm of that position. This would be its accuracy which may be improved by calibration. But if that position is taught into controller memory and each time it is sent there it returns to within 0.1mm of the taught position then the repeatability will be within 0.1mm.
Robotic Rotary Joint	Consisting of a stationary part connected to the arm of the robot and a rotating part connected to the wrist and tool allowing for electrical and pneumatic cables to stay in place while cables required for the tool are free to rotate. Electricity is provided by the used of a slip ring.
Roll	Rotation of the robot end effector in a plane perpendicular to the end of the manipulator arm.

Sensor	A device that responds to physical stimuli (heat, light, sound, pressure, magnetism, motion, etc.) and transmits the resulting signal or data for providing a measurement, operating a control, or both.
Speed	How fast the robot can position the end of its arm. This may be defined in terms of the angular or linear speed of each axis or as a compound speed
Swing	A robot’s rotational movement with respect to it’s centerline

Teach Mode	The control state that allows the generation and storage of positional data points affected by moving the robot arm through a path of intended motions.
Tool Changer	When several different end effectors will need to be used on the same robot, a tool changer simplifies the process by providing an “easy switch” interface between the end of the robot arm and the tool.
Touch Sensor	A sensor that senses physical contact between the robot and an object, giving the robot a “sense of touch."
Torque/Force Control	A control system capable of sensing forces and torques encountered during assembly or movement of objects, and/or generating forces on joint torques by the manipulator, which are controlled to reach desired levels.

Vacuum Gripper

An end-effector for a robot that uses suction to grasp light to moderate weight objects. It is commonly used because of its virtues of reduced object slide slipping while within the grasp of the vacuum cup.

Yaw	Side-to-side motion