Before revision: Closed-loop controllers have the following advantages over open-loop controllers: disturbance rejection (such as hills in the cruise control example above) guaranteed performance even with model uncertainties, when the model structure does not match perfectly the real process and the model parameters are not exact unstable processes can be stabilized reduced sensitivity to parameter variations improved reference tracking performance In some systems, closed-loop and open-loop control are used simultaneously.
After revision: improved rectification of random fluctuationsClosed-loop controllers have the following advantages over open-loop controllers: disturbance rejection (such as hills in the cruise control example above) guaranteed performance even with model uncertainties, when the model structure does not match perfectly the real process and the model parameters are not exact unstable processes can be stabilized reduced sensitivity to parameter variations improved reference tracking performance In some systems, closed-loop and open-loop control are used simultaneously.