A novel dead time compensator for stable processes with long dead times

• Published in: Journal of process control Vol. 22; no. 3; pp. 612 - 625
• Main Authors: Kirtania, Kawnish, Choudhury, M.A.A. Shoukat
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 01.03.2012
• Subjects: Dead time compensator; Regulatory control; Set-point tracking; Smith predictor; Stable processes; Two-degrees-of- freedom controller; Two-degrees-of-freedom controller; Dead time compensator; Stable processes; Regulatory control; Smith predictor; Set-point tracking
• ISSN: 0959-1524; 1873-2771; 1873-2771
• DOI: 10.1016/j.jprocont.2012.01.003

► A new simplified approach for the design of dead time compensators for processes with long dead time based on a modified structure of the Smith predictor. ► The proposed DTC structure is easy to analyze and tune. ► The proposed compensator has only two tuning parameters that determine the closed-loop performance and robustness. ► The performance of the proposed compensator is compared with the most recent dead time compensator proposed in the literature. ► To demonstrate its applicability to real processes, the method is evaluated on a two tank heating system pilot plant. This paper presents a new and simplified approach for the design of dead time compensators for processes with long dead times. The approach is based on a modified structure of the Smith predictor that allows the user to isolate the disturbance and set-point responses and thereby, provide a two-degrees-of-freedom control scheme. The proposed structure is easy to analyze and tune. Using an estimation of the dead time and process model of the plant, the proposed compensator is left with two tuning parameters that determine the closed-loop performance and robustness. The performance of the proposed compensator is compared with the most recent dead time compensator appeared in the literature. The method is evaluated on two simulated processes and a computer-interfaced pilot-scale two tank heating system to demonstrate the practicality and utility of the proposed scheme.