56 Abstract— A new approach of control design of internal model controller is proposed in this paper. The proposed design method focuses on modifying the old general structure of IMC and develops a new model structure while saving the same general concept of using the invertible version of the system in the controller design. The new approach combines the IMC structure and the traditional struc...

Given that a time-delay system is stable for some delay h0 > 0, a procedure is given to find the stability interval [h1, h ∗ 2] such that h0 ∈ [h1, h2] and for all h satisfying h1 < h < h ∗ 2 the system is stable. Further, the system is shown to be unstable if h = h1 or h = h ∗ 2. It is then shown how this can be applied to test the robust stability (with respect to delay values) of a Smith-Pre...

This paper presents a new methodology to design multivariable Smith predictor for n×n processes with multiple time delays based on the centralized inverted decoupling structure. The controller elements are calculated in order to achieve good reference tracking and decoupling response. Independently of the system size, very simple general expressions for the controller elements are obtained. The...

PID controllers are indisputably the most common controller type encountered in process control applications. They are used for regulating processes with diverse dynamics in industrial applications. Especially, processes with long dead times should require special attention as they are difficult to handle with conventional PID controllers. A lof of different dead time compensating control metho...

This paper presents a feedback control algorithm for ATM congestion control in which source rates are adjusted according to VC queue lengths at intermediate nodes along the path. The goal is to " ll in" the residual bandwidth, without exceeding a speci ed queue threshold. In order to obtain this, we propose a simple and classical proportional controller, plus a Smith Predictor to overcome insta...

According to the character of the volume-lag of the controlled process of three-tank-system, Smith predictor was adopted to compensate three-tank-system fuzzy adaptive control system. Fuzzy adaptive Smith predictive control system is composed with Smith predictor and fuzzy adaptive controller. The PID parameters were setting on line. This algorithm uses fuzzy adaptive PID control to improve the...

In this talk we investigate control problems for infinite-dimensional systems whose transfer matrices are expressible in terms of a rational transfer matrix and a scalar (possibly irrational) inner function. This class of systems is capable of describing many practical control problems, when weighting functions are rational and plants have at most a finite number of unstable modes or zeros. In ...

In this paper the following three control systems for first-order time-delay plants are studied and compared: the feedback proportional-integral controller (PI), the Smith Predictor (SP) and a proposed variable structure consisting of two blocks. This structure acts as an open-loop proportional controller, after a setpoint change, and as a closed-loop integrating controller, when the error ente...

In the paper the parallel compensator considered in [1] is applied to control of the plants with delay and compared with Smith predictor. It is noted that Smith predictor removes only the delay, while the parallel compensator also changes the dynamics of the replacement plant; the latter may be in some degree of freedom shaped by the designer. Owing to this the transients of the system with par...