Design of an Input-multiple Dual-rate Sampled-data Control System Using Null Space

Abstract

This paper discusses a design method for an input multiple single-input single-output dual-rate control system, where the sampling interval of the plant output is an integer multiple of the hold interval of the control input. A dual-rate control law that stabilizes a closed-loop system is extended using null-space. In the extended control system, a redundant input that is designed independently of the closed-loop system, is obtained. Because the redundant input is designed so that the control input is constant in the steady-state, the intersample ripples are eliminated without changing the reference response from the reference input to the plant output. Finally, the effectiveness of the proposed method is demonstrated through numerical examples.