Abstract: The proportional-integral-derivative controller is widely employed in process industries due to its simplicity, reliability and ability to achieve major control objectives. The Internal Model Control (IMC) design is a top-notch technique used for tuning these controllers for Single Input Single Output (SISO) systems with dead-time. Filter constant, Λ is a very important concept in the IMC design and proper estimation of the constant is fundamental. The following text studies the effect of varying the filter constant Λ from its ideal value to extreme values and understands the system behaviour for the differing filter constants for first order plus dead time model representing blending process. It was observed that improper estimation of Λ lead to unstable systems, large overshoots and highly oscillatory response which are completely undesirable in any control process. The inferences have been achieved with the aid of time domain analysis using MATLAB.
Avani Kirit Mehta and R. Swarnalatha, 2019. Design of PID Controller Using Internal Model Control Based Lambda Tuning for an Industrial Blending Process. Journal of Engineering and Applied Sciences, 14: 1486-1492.