Contents 1. Introduction
Nowadays, practical and modern control systems usually use digital computers as discrete-time controllers to control continuous-time systems. Such a control system involves both continuous-time and discrete-time signals and is called a sampled-data system [1]. Recently, some researches have been reported on digital control for nonlinear systems based on T-S fuzzy model [2], [3]. In [4], a digital controller stabilizing the discretized model of T-S fuzzy systems was proposed. But their results are only approximate formulations since the sampling of continuous time signals implies loss of some information. One can get better discretized models if one can make A/D and D/A conversions faster. However, this results in higher cost in implementation. An alternative approach is multirate input control scheme which updates the control inputs faster than the output measurements. In the past decades, there have been fruitful researches on multirate systems [5]–[7]. But their results basically work only for a class of linear systems. Thus, it is highly demanded to develop multirate control for nonlinear systems. So far, few efforts have been concentrated on utilizing multirate control technique in fuzzy systems except for [8], [9].
