Decentralized fractional-order controller for a granulation process

This paper develops a decentralized fractional control scheme for a widely used granulation process to enhance the closed-loop performance. A fractional filter-PI controller is designed for the granulator transfer function matrix. The control scheme is so designed to have an impact of fractionality in improving the closed-loop performance, yet preserving the simplicity of the Proportional-Integral (PI) controller. The proposed controller is a fractional filter coupled with an integer order PI controller. Stability and robustness assessment of the proposed controller is also carried out. Then, Relative Normalized Gain Array (RNGA) is employed to achieve the desired control-loop pairing for the decentralized scheme. Finally, the fractional filter-PI control is effectuated to the granulator control problem for testing the efficacy of the proposed method. Numerical simulations of the paper confirm the superiority of the closed-loop performance resulting from the proposed controller of the paper in contrast to the conventional controller.