Simple tuned adaptive PI controller for conical tank process

Abstract

This paper proposes an idea for designing a continuously tuned adaptive PI controller for a non-linear process such as conical tank. In this paper, a simple tuning system is used to continuously tune the controller parameters in correspondence with the change in operating points. For each stable operating point, a FOPTD model was identified using process reaction curve method. The estimated model parameters are used to calculate the controller parameters for each operating points. Based on these calculated controller parameters and its operating points, a tuning system was created. The tuning system will able to interpolate and extrapolate the relation between control variable and the controller parameters over entire span of control variables. Finally, a detailed time-domain modeling of the conical tank was performed. Then the adaptive PI controller was implemented in Matlab and was simulated to verify its performance. Thus the adaptive controller was able to produce a consistent response regardless of parametric variations with minimum overshoots and minimum settling time.