Optimising a robustness margin using simple parameterised models

Compared with a controller based on a fall plant model, a controller based on a simple approximate plant model requires less computational effort and is of lower order. According to robust control theory, such a controller also stabilizes the original and more complicated plant if a robustness margin is less than unity. The authors consider methods for deriving simple optimal parameterized plants and present a method which optimizes a robustness margin of the form K /(1+KG_A). This margin is dependent on the choice of controller. The results obtained are promising