Patent ID: 8401676

Claim:
A method for controlling a plant, comprising: receiving a reference signal at a feedback controller comprising signal transformation blocks for signal transformation; wherein the signal transformation blocks translate signals between a first frequency domain and a second frequency domain; and generating by the feedback controller a disturbance signal in addition to a nominal signal as an output of the feedback controller; receiving the reference signal at a feed-forward controller, the reference signal received at the feed-forward controller being a same as recived at the feedback controller; recreating by the feed-forward controller a recreated disturbance signal to be a same as the disturbance signal that was caused by the signal transformation blocks, the recreated disturbance signal from the feed-forward controller being generated separate from the disturbance signal from the feedback controller; creating an input to the plant by: adding the output of the feedback controller; and subtracting the recreated disturbance signal generated by the feed-forward controller from the output generated by the feedback controller to remove the disturbance signal from the input to the plant; and adding the recreated disturbance signal from the feed-forward controller to the output of the plant; wherein the recreated disturbance signal from the feed-forward controller is applied to both the input and the output of the plant.