Control

Cascade Control

Cascade control is a nested control architecture in which an outer loop's output serves as the setpoint for a faster inner loop, such as a position loop commanding a velocity loop that commands a current loop in a motor drive. The inner loop rejects fast disturbances locally, while the outer loop handles slower task-level objectives. Proper tuning requires the inner loop bandwidth to substantially exceed the outer loop's.

Why it matters for physical AI

Nearly every robot actuator runs cascaded loops beneath learned policies; knowing which loop a policy commands, and at what rate, determines achievable smoothness, compliance, and the fidelity of executed actions.