What is a Tool frame?

• A. A frame fixed to the robot base and remains stationary.
• B. A frame attached to the end of the robot arm and moves with the robot.
• C. A frame defined relative to the world frame that never changes.
• D. A frame defined relative to the fixture that stays fixed.

Answer: (B)

In robotics, a Tool frame is the coordinate system attached to the end effector—the tool at the end of the arm. It moves with the robot as the arm articulates, so its origin and orientation travel with the tool itself. This makes it natural to describe and control the tool’s position and orientation in its own reference frame, often with the origin at the tool tip and axes aligned with the tool’s operation.

That’s why the tool frame is different from other frames: the base frame is fixed to the robot’s base and stays stationary, the world or fixed frames stay put in the workspace, and a fixture frame remains fixed relative to a fixture. The tool frame’s key property is that it travels with the end effector, providing a convenient reference for tool-centric motions and tasks.