LMI APPROACH FOR ROBUST CONTROL OF SYSTEM WITH UNCERTAINTY IN TIME DELAY
|Shyma Muhammed1, Dr. Abraham T Mathew2
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Control of time delay systems has been a challenging problem for the control engineers. The issues have been inviting attention of many researchers, especially in the context of robust control. This is further motivated by the fact that many processes have the time delay present in the corresponding models and thus the design of controller becomes computationally rather involved. Time-delayed systems are pervasive in many engineering systems such as tele-robotic systems, vehicle platoons, biological systems, chemical processes etc. The presence of delay in these systems makes closed-loop stabilization difficult and degrades tracking performance. The problem becomes extremely difficult when uncertainties are present in the model as well as in the delay parameter. It is known that, in general, the delays appear in the system models due to various factors like transport phenomena, computational time needed for generation of control command, time delay in the smart measurement devices, approximation of a higher order system with a lower order model etc. This paper is concerned with the robust control of linear varying time delay system using LMI approach. Also this paper develops a control technique for uncertain linear time delay systems in which both plant uncertainty and controller uncertainty are taken into account.