Author(s)

Michael Short¹, A. Arockia Selvakumar²

¹School of Computing, Engineering and Digital Technologies, Teesside University, Middlesbrough, UK.
²Design and Automation Research group, School of Mechanical and Building Sciences, Vellore Institute of Technology, Chennai, Tamil Nadu, India.

Tank level control is ubiquitous in industry. The focus of this paper is on accurate liquid level control in single tank systems which can be actuated continuously and modulation of the level setpoint is also required, for example in cascade control loops or supervisory Model Predictive Control (MPC) applications. To avoid common problems encountered when using fixed gain or adaptive/gain scheduled schemes, an accurate technique based around feedback linearization and Proportional Integral (PI) control is introduced. This simple controller can maintain linear performance over the full operating range of a uniform tank. As will be demonstrated, the implementation overhead compared to a regular PI controller is negligible, making it ideal for industrial implementation. Implementation details and parameter identification for adaptive implementation are discussed. Simulations coupled with experimental results using a large-scale laboratory level control system using commercial industrial control equipment validate the approach, and illustrate its effectiveness for both level tracking and disturbance rejection.

Level Control, Non-Linear Control, Feedback Linearization

Short, M. and Selvakumar, A. (2020) Non-Linear Tank Level Control for Industrial Applications. Applied Mathematics, 11, 876-889. doi: 10.4236/am.2020.119057.