Discrete compensation of sampled-data and continuous control systems

This paper presents a method of compensation to be applied to continuous as well as to sampled-data systems which reduces to zero any overshoot or error after a prescribed finite time. This prescribed response is applicable to step or ramp inputs and could be extended to acceleration or higher order inputs. It is shown that this response can be accomplished using the modified z-transform1 which yields the system response for all instants of time. The procedure, illustrated in examples, is applicable to general linear physical systems with no inherent delays. The compensated system may be designed so that shifts in gain or other dynamical disturbances have a small effect on the prescribed response. In conclusion, the method presented is powerful in synthesizing control systems to tally with a prescribed response and furthermore is straightforward in its application.