Control

Virtual Model Control

Virtual model control is a control technique that emulates imaginary mechanical components, such as springs and dampers, attached between points on a robot and its environment, computing the joint torques those components would exert if they physically existed. Developed by Pratt and colleagues at the MIT Leg Laboratory for bipedal walking, it provides an intuitive, low-dimensional way to specify compliant, force-based behaviors without explicit trajectory planning.

Why it matters for physical AI

Specifying behavior as virtual springs and dampers remains a core idiom for legged locomotion and compliant manipulation, and it connects directly to the impedance controllers that keep contact-rich learned behaviors stable on hardware.