Hardware & control
Mobile manipulation
Mobile manipulation is the coordinated use of locomotion and manipulation by a robot that combines a mobile base or body with one or more arms or other manipulators. Mobility expands the robot's reachable workspace, while the manipulator grasps, pushes, operates tools or makes contact; the base and arm may move separately or at the same time.
Also known as: mobile manipulator, mobile manipulators
Updated
Mobility changes the reachable workspace
Modern Robotics defines a mobile manipulator as a mobile base equipped with one or more robot arms. A fixed arm can manipulate only within its installed workspace. A mobile manipulator can reposition the base, carry an object between locations and approach several stations with the same arm.
Wheels are common, but mobility can also come from tracks or legs. A humanoid that walks to a shelf and picks an object is performing mobile manipulation even though its limbs and base are part of one articulated body.
The base and manipulator must be coordinated
A simple system can drive to a location, stop and then move its arm. Harder tasks require simultaneous motion. Khatib's mobile-manipulation framework treats the mobile base as a coarse, slower mechanism and the arm as a faster, more accurate manipulator, then coordinates both around the end-effector task.
Coordination matters when opening a large door, carrying an object while walking or following a surface that extends beyond the arm's stationary reach. The controller must allocate motion between locomotion and arm joints while respecting collisions, joint limits, balance or wheel constraints and contact forces.
Mobile manipulation is not one autonomy level
The term describes a physical capability, not how decisions are made. A mobile manipulator may be autonomous, teleoperated or use variable autonomy. The wheeled mobile-manipulation survey covers applications ranging from inspection to logistics resupply and assembly under both autonomous and teleoperated control.
For training data, a mobile-manipulation episode should preserve base pose and velocity, arm and hand state, end-effector targets, sensor observations, actions, contacts and the timing between navigation and manipulation. Recording only the hand trajectory loses the body movement that made the task reachable.
Sources
Related terms
Hardware & control
End effector
An end effector is a task-specific device attached to a robot manipulator’s mechanical interface so the robot can act on its environment, such as a gripper, hand or welding tool. It is distinct from the wrist or mounting flange, and from the tool centre point, which is only a coordinate frame used to plan the device’s motion.
Hardware & control
Whole-body control
Whole-body control coordinates a humanoid’s full multibody state, actuated joints and environmental contacts to pursue several motion or force objectives while respecting constraints such as balance, joint limits and friction. It is a family of hierarchical or optimisation-based methods, not one algorithm; implementations may output joint positions, accelerations or torques.
Hardware & control
Robot kinematics
Robot kinematics describes the geometric relationship between a robot’s joint configuration and the position, orientation and velocity of its links or end-effector, without modelling the forces that cause the motion. Forward kinematics computes pose from joint values; inverse kinematics searches for joint values that achieve a requested pose.
Hardware & control
Degree of freedom
A degree of freedom (DoF) is one independent parameter needed to specify a robot’s configuration; equivalently, a robot’s DoF is the dimension of its configuration space. It describes possible motion, not the number of motors. Joint constraints, closed kinematic chains and environmental contacts can make joint count, actuator count and controllable motion differ.
Hardware & control
Feedback control
Feedback control is a closed-loop control method that measures a system’s current output or state, compares it with a target and adjusts the command using the resulting error. In robotics, feedback can correct joint, end-effector, balance or force errors as new sensor measurements arrive.