2-DOF Preview Feedforward Sliding Mode Controller for the Control of Multivariable Process with Dead Time

Abstract

This paper proposes a 2-DOF preview feedforward sliding mode controller (PFFSMC), which has a combination of feedback and feedforward terms in the sliding surface, for controlling the multivariable process with dead time, for both set point tracking and disturbance rejection. The proposed controller is applied for the control of the Wood and Berry binary distillation column having the composition of top and bottom products. The performance of the 2-DOF PFFSMC is compared with that of the 1-DOF preview sliding mode controller. The proposed controller delivered better responses for set point tracking and for disturbance rejection. The performance of the proposed 2-DOF PFFSMC is compared with the other controllers reported in the literature and, it was found that there was a significant reduction in the settling time by more than 76%, without any overshoot in the closed loop response. The proposed controller was robust against ±5% parametric uncertainties in gain, time constant, and dead time when these uncertainties were considered alone and together. The stability of the proposed controller was verified using the Lyapunov stability criterion.

KEYWORDS:

• Dead time
• Feedforward control
• Multivariable process
• Preview control
• Sliding mode control
• 2-DOF Control

Disclosure statement

No potential conflict of interest was reported by the author(s).

Additional information

Notes on contributors

P. Vidya

P Vidya was born in India, in 1982. She received the BTech (Instrumentation and Control) from Calicut University, Kerala, India, in 2004, and ME (Applied Electronics) from Anna University, India, in 2014. Currently pursuing PhD in instrumentation and control systems engineering from Anna University, India. Her current research interests include control systems and process control. Email: [email protected]

J. Arunshankar

J Arunshankar was born in India in 1974. He received the BE (Electronics and Instrumentation Engineering) from Bharathiyar University, India, in 1995, an ME (Process Control and Instrumentation Engineering) from Annamalai University, India, in 1998, and PhD in instrumentation and control engineering from National Institute of Tiruchirappalli, India, in 2011. Since 2008, he has been with the Department of Instrumentation and Control Systems Engineering, PSG College of Technology, Coimbatore, India. His research interests are in the areas of process control and state estimation.