Impedance control
A robot control mode that regulates the dynamic relationship (impedance) between joint position and applied force, rather than directly regulating position or force alone. Impedance control requires a backdrivable actuator or a compliant element; non-backdrivable high-ratio gearboxes cannot implement true impedance control because they block the force transparency needed to feel and respond to contact. The target impedance (virtual mass, damping, and stiffness) is set by the control law; the actuator must be capable of generating the forces implied by that impedance across the full range of contact velocities the task produces.
Defined in 2 GAGE programs, which carry 4 distinct definitions of it. The wording above is taught in Foundations of Robotics and Physical AI.
How each discipline defines it
The same term does different work depending on who is using it. These are the definitions as each program teaches them, unedited.
A robot control mode that regulates the dynamic relationship (impedance) between joint position and applied force, rather than directly regulating position or force alone. Impedance control requires a backdrivable actuator or a compliant element; non-backdrivable high-ratio gearboxes cannot implement true impedance control because they block the force transparency needed to feel and respond to contact. The target impedance (virtual mass, damping, and stiffness) is set by the control law; the actuator must be capable of generating the forces implied by that impedance across the full range of contact velocities the task produces.
A control strategy, closely related to active compliance, in which a robot's controller is designed to regulate the dynamic relationship between force and motion at a joint or end-effector, rather than commanding position alone, so that the joint behaves as if it had a programmable, adjustable stiffness and damping in response to external force.
A motion-control mode in which the servo joint is commanded to behave as a mechanical impedance (virtual spring plus damper) rather than to achieve a specific position. The restoring force toward the commanded position is proportional to position error (spring term) and to velocity error (damper term). Unlike position PID, impedance control explicitly limits the contact force by bounding the virtual spring constant, enabling safe interaction with environments of uncertain stiffness.
A force-control architecture in which the robot is commanded to behave as a virtual mechanical impedance (spring-mass-damper). Position deviations from a reference are resisted with a specified stiffness. Well suited to robots with inherent mechanical compliance operating in stiff environments.
Terms it appears with
Not an alphabetical neighbourhood: these are the terms taught in the same lessons, ranked by how often they appear together.