Control

Cartesian Impedance Control

Cartesian impedance control is a compliance control scheme that regulates the dynamic relationship between end-effector pose error and interaction force in task space, making the robot behave like a virtual spring-damper system attached to a target pose. Introduced conceptually by Hogan (1985), it maps Cartesian stiffness and damping through the manipulator Jacobian to joint torques, requiring torque-controlled joints. It enables safe, stable contact without explicit force setpoints.

Why it matters for physical AI

Compliant task-space behavior lets learned policies command poses while the controller absorbs contact uncertainty, a common recipe for contact-rich skills like insertion and wiping on torque-controlled arms.