Open-loop Control

Open-loop control executes a pre-planned trajectory without using sensor feedback during execution — the robot simply follows the commanded positions or velocities regardless of what actually happens. This is appropriate for highly repeatable tasks in controlled environments, such as CNC machining or pick-and-place on a fixed conveyor. Open-loop control is fast and simple but fails when disturbances occur, because no corrective action is taken. In contrast, closed-loop (feedback) control continuously compares the actual state to the desired state and applies corrective commands, making it far more robust for robot learning in variable environments.

See this in practice: the hardware store →