Robotics
Workspace
Definition
A robot workspace is the set of positions or poses its end-effector can reach under specified geometric and joint constraints. Its meaning depends on whether orientation is included and which base and tool configuration are assumed.
Also known as: Robot workspace, Reachable workspace
Updated
Reach includes assumptions
A reach envelope shows where a robot's end-effector can go. Link geometry and joint travel limits shape that envelope. Specifying the robot base and tool frame matters because changing either changes the positions being described.
Modern Robotics distinguishes a position-only workspace from a workspace that includes orientation. A hand may reach a point without being able to approach it from every direction.
Reachable and dexterous workspaces
The dexterous workspace is commonly the subset of positions reachable with all end-effector orientations. It is therefore more restrictive than simply reaching each position with at least one orientation.
Task space is different again: it is the space in which a task is naturally expressed. Drawing on a board can use a two-dimensional task space even when the robot itself has more degrees of freedom.
Reachability is not a motion guarantee
A reachable target does not identify which joint posture to use or a route to that posture. Those are inverse kinematics and motion planning questions. Reach also does not imply equal motion capability everywhere: the singularity lesson shows how a fully extended arm can lose an instantaneous direction of end-effector motion.
Sources
Related terms
Configuration space
Configuration space is the set of all possible configurations of a robot or mechanical system. Each point specifies the entire modeled arrangement, and the space has as many local dimensions as the system has degrees of freedom.
Inverse kinematics
Inverse kinematics finds joint positions that produce a desired robot end-effector position, orientation, or other geometric task. A target can have multiple solutions, no solution, or a continuous family of solutions.
End effector
An end effector is the part of a robot positioned to perform a task at the end of a manipulator, such as a gripper, hand, suction tool, or welding tool. Its pose and interaction forces are often the quantities a task controller regulates.