An exact method for compensation of discrete data systems in the z-plane†

Abstract

A compensation design technique is presented for discrete data automatic control systems which enables simultaneous satisfaction of specifications on the transient response and the steady-state error of the system. A unique design is possible with this technique, which avoids the usual trial-and-error process. The design is obtained through the solution of a set of equations giving the location of the real pole and zero of a cascade or feedback compensator which causes a pair of complex-conjugate roots of the characteristic equation to exist at a designated location in the z-plane, simultaneously with satisfaction of a specified open-loop gain, which may be different from original system gain. Thus, in effect, the method allows the designer to simultaneously specify the gain margin or relative stability of the system, as well as its steady-state accuracy, which may be modified from its original value. The technique is illustrated by means of a practical example.

Notes

†Communicated by the Author.