Open Loop
The positioning system does not use feedback to determine whether its output has reached the desired target of the input command or process setpoint.
The feedback behavior of the controller is independent of the process variable to be controlled. It does not use feedback to determine whether its output has reached the desired target of the input command or the process setpoint.
The advantage of using controllers in these cases is the reduction of the number and complexity of the components. However, an open loop system cannot correct any errors it makes or correct external disturbances, and it cannot perform machine learning.