Degrees of freedom

How it is used

Often written DOF or DoF and used with a number before a noun: a 6-DOF arm, a 7-DOF cobot. It appears in data sheets, lectures and design discussions. In industry people often say 'axes' with almost the same meaning: a six-axis robot.

Example sentences

1. A SCARA robot has only four degrees of freedom, but that's enough for most assembly tasks on a flat table.

2. The seventh degree of freedom lets the arm reach around obstacles.

Common collocations

• six degrees of freedom
• 6-DOF arm
• redundant degree of freedom
• number of degrees of freedom

Related terms

• axisOne controlled direction of motion, either a rotation or a straight-line movement, driven by its own motor. Also a line in a coordinate system, such as the X, Y or Z axis.
• jointA connection between two parts of a robot arm that allows movement. A revolute joint rotates and a prismatic joint slides in a straight line; each joint is usually one axis.
• kinematicsThe study of motion without looking at the forces that cause it. In robotics, it describes how the joint angles relate to the position and orientation of the tool.
• articulated robotA robot arm with a series of rotary joints, usually six, arranged like a human arm with a shoulder, elbow and wrist. It is the most common type of industrial robot.
• SCARA robotA fast robot, usually with four axes, whose arm moves in a horizontal plane and has a vertical axis at the end. SCARA stands for Selective Compliance Assembly (or Articulated) Robot Arm.

This word in other fields

The same English word can have a different meaning in another field:

• degrees of freedom · Statistics

More terms: Motion and Kinematics

• work envelope
• tool center point
• coordinate frame
• repeatability
• accuracy
• trajectory
• inverse kinematics
• singularity