UDC 681.515
REFITTING PID REGULATOR FOR UNSTABLE OBJECTS WITH LAGS INTO FILTERED SMITH PREDICTOR
A. I. Bobikov, Ph.D. (Tech.), associate professor, department of automation and information technologies in control, RSREU, Ryazan, Russia;
orcid.org/0000-0001-7440-3118, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
T. S. Bubnova, postgraduate student, department of automation and information technologies in control, RSREU, Ryazan, Russia;
orcid.org/0000-0002-7085-0591, e-mail: This email address is being protected from spambots. You need JavaScript enabled to view it.
This article discusses a technique for re-equipment of PID controllers used to control unstable objects with delay into a filtered Smith predictor. The aim of the work is to reduce overshoot, increase the speed of control system, and also reduce the influence of disturbing influences on the operation of the system. The article shows how you can choose the parameters of two controllers included in the structure of the Smith predictor in order to obtain a system that is equivalent to a system with a PI controller in terms of response to a disturbance. Such a system provides the best quality indicators when solving the problem of tracking a constant reference input by compensating for the lag achieved using the Smith predictor. To improve the response to the disturbing action, a filter was added to the feedback, the structural features of which, in particular the difference from the unit of its inherent gain, make it possible to reduce the influence of disturbing actions. Modeling was carried out on the example of unstable objects with delay in the Matlab /Simulink package, the presented results show the effectiveness of the proposed design technique.
Key words: object with delay, unstable object, Smith predictor, PID controller, filter.