A stable hybrid adaptive algorithm with periodic sampling and gain adjustment

In this article a hybrid algorithm for model reference adaptive control of single-input single output systems is presented. The control structure involves a continuous time as well as a discrete time part, instead of being all discrete or all continuous as in previous approaches. The system is sampled periodically at a frequency F, and knowledge of bounds on the plant parameters enables us to determine a bound F* such that the closed loop system is stable whenever F > F*.