Proposal of generalized digital redesign method in use of N-delay control

A digital redesign method is proposed for feedback control systems, by which the states in the continuous-time system are completely reserved in the redesigned sampled-data system. The features of the proposed method are: 1) the N-delay control is employed, and the lth plant input is changed N₁ times during one sampling period, 2) the states of the redesigned sampled-data system completely match those of the original continuous-time closed-loop system at every sampling period, and 3) the proposed redesign method can be applicable for a state-feedback and/or a dynamic controller. An illustrative example of position control using a DC servo motor is presented, and the advantages of redesign approach are demonstrated