Comparison of Systems for Control of Objects with Delay Time with Use of Smith Predictor and with Coordinate Recovery

A system for regulating the diameter of optical fiber glass in the process of manufacture is considered. The object possesses pure time delay. In control systems with time delay as in the present case Smith predictors are usually used to reduce the length of the transient process and the control error, though these require construction of a model of the object with time delay. The present article proposes recovery of the coordinate of the controlled quantity prior to time delay in order to then use the coordinate at the inlet to the controller. Finite differences are used to recovery the coordinates, moreover there is no need to construct a model of the object with time delay, that is, maintenance of the precision of the model is not required.