A New Analytical Approach for Set-point Weighted 2DOF-PID Controller Design for Integrating Plus Time-Delay Processes: An Experimental Study

Abstract

In many industrial processes, e.g. temperature and level control, chemical reactors can be classified as a variant of integrating plus time-delay system. Controlling these processes is a difficult task due to open-loop instability, which consists of time-delay and unbounded output for bounded input. 1DOF PID control always leads to a large overshoot in set-point tracking for IPTD processes. In a 2DOF PID structure, tuning the set-point weights and the controller parameters is important to achieve good tracking and disturbance rejection properties. But tuning the set-point weights and the parameters of the cascade-feedback controller together is a difficult task. Usually, predetermined values for set-points are chosen, and a controller design is followed. In the present work, an alternative simple approach to obtain controller parameters along with set-point weights is presented which are tuned to yield good tracking and load–disturbance rejection. Explicit controller parameters for different classes of integrating processes are obtained using gain-margin, phase-margin, and inverse plant model which can also be used for controller auto-tuning. To validate the effectiveness of the proposed controller, simulation comparisons with some recently developed methods are included. Moreover, the experimental validation of the proposed controller on a temperature control plant is also presented.

Keywords:

• 2DOF-PID
• Integrating plant
• Time-delay
• Internal model principle
• Gain and Phase margin
• Set-point filter

Disclosure statement

No potential conflict of interest was reported by the authors.

Additional information

Notes on contributors

Sudipta Chakraborty

Sudipta Chakraborty obtained his BTech degree in electronics and instrumentation engineering from WBUT, India, in 2012. After which, he received his MTech degree from National Institute of Technology Rourkela, India, in 2014. In 2018, he was awarded PhD degree in electrical engineering from the same institute. He is currently working as an assistant professor in Department of Electronics and Instrumentation Engineering, National Institute of Technology Silchar, India.

Jiwanjot Singh

Jiwanjot Singh obtained his BTech degree in electrical engineering from Punjab Technical University, India, in 2008. After which, he received his MTech degree from PEC University of Technology Chandigarh, India, in 2011. In 2018, he was awarded PhD degree in electrical engineering from National Institute of Technology Kurukshetra, India. He is currently working as an assistant professor in Department of Electrical Engineering, National Institute of Technology Silchar, India. Email: [email protected]

Asim K. Naskar

Asim K Naskar obtained his BTech degree in electrical engineering from Jadavpur University, India, in 2001. After which, he received his MTech degree from the same Institute in 2006. In 2015, he was awarded with PhD degree in electrical engineering from Indian Institute of Technology, Kharagpur, India. He is currently working as an assistant professor in the Department of Electrical Engineering, National Institute of Technology, Rourkela, India. Email: [email protected]

Sandip Ghosh

Sandip Ghosh obtained his BTech degree in electrical engineering from Indian Institute of Engineering Science and Technology Shibpur, India, in 1999. After which, he received his MTech degree from Jadavpur University, India, in 2003. In 2010, he was awarded with PhD degree in electrical engineering from Indian Institute of Technology, Kharagpur, India. He is currently working as an associate professor in the Department of Electrical Engineering, Indian Institute of Technology, BHU, India. Email: [email protected]