Optimal feedforward tracking controller design

This paper presents a new type design methodology for the feedforward controller in discrete time systems. For a sinusoidal input, if the frequency of desired trajectory is known in advance, this controller exhibits a zero phase error tracking performance. On the other hand, if the weighting parameter is not zero, the controller is causal, stable and one can make the tracking error arbitrary small by choosing the weighting parameter small enough. If the weighting parameter is zero then the controller may be noncausal; however, it makes a perfect tracking. In addition, for the special case of zero weighting parameter and a DC command signal, a optimal feedforward tracking controller is obtained. In this paper, we called this controller a “zero gain error tracking controller”. Finally, a non-minimum phase plant is used to show the effectiveness of this proposed controller