Abstract:
Dead time is commonly found in chemical processes. Signi cant amount of dead
time can lead to unsatisfactory and unstable process operation. Therefore, dead
time estimation and compensation is very important for processes with long dead
time. In this study, a new dead time compensation technique for stable processes
has been developed.
The estimation of dead time is developed using a numerical technique. Numerical
Integration is used to detect dead time from step response data of a process. The
method was evaluated and validated in simulation. Later, this method has been
used to detect dead time from step response data of a real process. The dead time
estimation technique performs well up to a certain amount of noise present in the
system.
The dead time compensation method is developed by modifying the classical dead
time compensator structure. Two new lters are introduced in the traditional
compensator. New rules for tuning the controller and the parameters of the lters
are developed. The performance of the newly proposed dead time compensator
has been compared with the most recently appeared dead time compensator in
the literature using both simulation and experimental studies. A pilot scale two
tank heating system is used for experimental evaluation of the proposed dead
time compensator. The dead time compensator outperforms the most recently
appeared dead time compensator. The reliability analysis is performed to test the
robustness of the proposed method. The reliability analysis shows that the newly
developed dead time compensator can handle some uncertainties in the estimation
of dead time and process model.
