Synthesis of control systems

FEEDBACK CONTROL SYSTEM DESIGN is most effective when both steady-state and transient performance specifications can be realized. One approach, synthesis, proceeds from a set of closed-loop specifications to an appropriate open-loop system which, upon closure of the feedback path, satisfies the specifications. Almost without exception, a compensation network must be used in conjunction with the fixed portion of the system G2 (s). In many cases it is desirable that the compensation network consist of resistance and capacitance elements. To be R-C realizable, the poles of the transfer function describing the compensation network must be simple on the negative real axis, the origin and infinity excluded, i.e., its pole-zero excess must be equal to or greater than zero.