In general, industrial processes have a multi-variable characteristic, which is sensitive to the disturbances. Therefore, it is important to study the influences of disturbance through a simple but reliable tools. Quadruple tank is a simple tool in process control that represents a complex multivariable dynamic process. This article investigates the effects of an introduction of heaters to the system as well as the interaction among the tanks. The flow rates and energy inputs to the tanks, respectively, are considered as the manipulated variables, while the liquid temperatures and level are controlled; hence the system becomes a 4x4-MIMO. The closed loop simulation is designed for comparing controlled variable response between P only-PID and IMC conroller. Error criteria is evaluated by IAE. In level change of minimum phase, IAE's value of level and temperature controller IMC show better result than P-only. On the contrary, P-only controller indicated faster response (settling time) than IMC. IMC is used for solving time delay problem on conventional controller. Thus, based on settling time and wide range of tolerance, P-only shows a better work than IMC. However, using IMC is the best decision if the accuracy and precision from set point are the main of controlling system. In temperature change, based on settling time and IAE, IMC gives the best result than both P-only for level controlling and PID for temperature controlling. Divergent oscillation of controlled variable response, wether level or temperature, of non-minimum phase indicates unstable trend and hard to control by P-only for level and PID for temperature. In contrary, temperature change controlled variable result of IMC, either lavel control or temperature control, are indicated better result than P-only and PID. As a result, IMC controller can be considered to be a reference at non-minimum phase control system.
|Number of pages
|ARPN Journal of Engineering and Applied Sciences
|Published - 20 Apr 2016