Design and implementation of discrete PID control applied to Bitumen tank based on new approach of pole placement technique

Abstract

This paper develops a novel approach for pole placement method of discrete proportional-integral-derivative (PID) control with industrial application of Bitumen system. The approach utilizes first order discrete-time transfer function (TF) with samples time delay more than unity for tuning the PID compensators, in order to achieve a priori set point of Bitumen mixing temperature. The work also introduces the well established Ziegler Nichols (ZN) and Chien-Hrones-Reswick (CHR) tuning techniques of discrete PID control, when applied to the same TF of Bitumen system, as benchmark. Bitumen system, sited at INSUMAT Company, is considered as a demonstrator for which the discrete PID control with the novel discrete pole placement approach is applied. Here, it is required to achieve a certain temperature for the Bitumen prior to the mixing process with the additives (polymers and fillers) in order to achieve a certain properties for insulation purposes. The key factor for the mixing process is the temperature of Bitumen which should not exceed \(\pm 5\,\%\) of the specified temperature, which ranges from 90 to \(180\,^{\circ }\hbox {C}\), to avoid reaching self-ignition state for the vapor inside the tank (\(\sim \)220\(\,^{\circ }\hbox {C}\)). This explains the avoidance of using conventional online tuning for PID compensators. Simulation results verify the applicability of the new approach and show satisfactory steady state response with very good control action when compared to the noisy control action of the ZN and CHR techniques. Finally, the paper shows successful implementation ‘onsite’ for the discrete PID control using the new approach for pole placement technique, for which all the control design criteria are verified.