Author : Karthik Krishnan and G.Karpagam

Control of liquid level in the process tank is important in process industries. A PID controller is otherwise called as three term control is taken up here for discussion and analysis. It has three constant parameters and they are proportional, integral and derivative values which depend upon the present error, aggregation of past errors and anticipation of future errors based on current rate of change of error respectively. It is highly used in chemical industries because of their success rate in practical applications, robustness and simplicity. In this work, various PID control tuning techniques are used designed. At first, the real time level process is identified as first order plus dead time model. To find the effective controller parameters settings, a conventional PID control tuning techniques and model based PID were analyzed and their simulation results were to be obtained. The effectiveness of various PID controller are highlighted with the aid of time domain and error criterion analysis. The best among the tuned controlled technique is emerged out as a good result of minimum rise time, setting time and is highlighted.

Keywords: PID controller, Level Process, Internal Model Control (IMC).

Article published in International Journal of Current  Engineering  and Technology, Vol.4,No.4 (Aug- 2014)