Fractional-Order PI Controller with Specific Gain–Phase Margin for MABP Control

Abstract

ABSTRACTMean arterial blood pressure (MABP) is one of the most important clinical parameters which is required to be controlled very accurately. Therefore, it is very essential to have an efficient and precise control strategy for regulating the MABP in various clinical conditions, which can work well in uncertain operating environment, and also show good disturbance rejection. Although the fractional-order control scheme has evolved as a strong control strategy in recent times, the design techniques available in the literature are mathematically very complex and hence limit the usage of fractional-order controllers. Moreover, it is observed that the gain and phase margin based techniques that exist in the literature for integer order systems are not completely applicable to the fractional-order systems. Therefore, in this paper, a design scheme is proposed for fractional-order PI controller based on gain and phase margins for controlling the MABP. The beauty of the proposed technique is that the controller designed is found to give better disturbance rejection than the conventional proportional integral (PI) or the IMC-PI controllers for nominal as well as the sensitive and insensitive patients. Thus, the technique proposed here gives the dual advantage of computational simplicity as well as robust controller performance.