Ripple-free design for an SISO dual-rate control system

Steady‐State Dual‐Rate Open‐Loop Transfer Function Model‐Based Ripple‐Free Design

“…In the conventional extension methods [2,[4][5][6], the dynamic characteristic of the controlled plant is required to maintain the transient response as well as the steady-state response. On the other hand, the proposed method is designed based on the steady-state characteristic of the open-loop transfer function model.…”

“…In this method, a control law is extended independent of the existing sampled response. Furthermore, redundant input [3]-based extension methods using the null-space have been also proposed [4][5][6][7].…”

“…Even though the design methods are useful for eliminating the steady-state intersample ripples, the dynamics of the controlled plant must maintain the transient response as well as the steadystate response [2,[4][5][6]. When the design objective is to eliminate the steady-state ripples, the preservation of the discrete-time transient response is not essential, and only the discrete-time a Correspondence to: Takao Sato.…”

Quantitative Evaluation in Discrete-time Domain and Improvement in Intersample Response on Multirate Optimal Control

“…Since the sampling interval of the plant output is an integer multiple of the holding interval of the control input, the following lifted dual-rate model is obtained [Equations (3)- (5)].…”

“…When the intersample response is improved, the discrete-time sampled response might be degraded, and hence the performance degradation should be fairly evaluated. The extension method using the null-space has been proposed [5,6]. The conventional method [5] is derived using the polynomial approach, whereas the proposed method is designed based on the state-space representation.…”