Analysis of mufti-rate predictive control systems

In this paper, the analysis on two control systems is made by the method of dynamic matrix predictive control. One is a multi-rate control system, in which the output sampling interval is an integer multiple of the control interval; the other is a fast single-rate control system. For a control system in the presence of model-plant mismatch, the model-plant gain ratio K can affect the control quality of system. When K is larger, the control quality of multi-rate system is better than the single-rate one, when K is smaller, the conclusion is exactly reversed. Therefore, under the feasibility of physical constraints, according to the different intervals of K belongs to, we can choose different control methods relevantly to increase stability and reduce overshoot of system.