Task Frames in Robot Manipulation

Dana H. Ballard

Most robotics computations refer to a single world- based frame of reference; however, several advantages accrue with the introduction of a second frame, termed a task frame. A task frame is a coordinate frame that can be attached to different objects that are to be manipulated. The task frame is related to the world-based coordinate frame by a simple geometric transformation. The virtues of such a frame are: (1) certain actions that are difficult to specify in the world frame are easily expressed in the task frame: (2) the task-frame to task-uorld transformation provides a formalism for describing physical actions; and (3) the task frame can be related to the world frame by proprioception.
