- Gumelar Ahmad Muhlis (NRP. 2313 105 009)
- Nia Fauziah Lestari (NRP. 2313 105 017)
Chemical Engineering, FTI – ITS
- Juwari Purwo Sutikno, ST., M.Eng., Ph.D
- Prof. Ir. Renanto Handogo, MS., Ph.D
Generally, processes in the industry have the characteristics of a multi-variable process, and influenced by the disturbances. Quadruple tank process is a simple prototype which represented the complex multivariable dynamic process. However, this system doesn’t have time delay that always occure in industrial process. Thus, in this study, we modify the system by adding heater in tank 1 and tank 2. In addition, interaction between tank 1 and tank 2 was created. Manipulated variables are flowrate from pump 1 and 2, energy input to tank 1 and 2. Controlled variables are level on tank 1 and 2, water temperature on tank 1 and 2. The system is become MIMO 4×4. This research utilize mathematics model from the last research and determine the spesification and process parameter, furthermore simulate the system using LabView software. The transfer functions are identified by step test method, then the interaction analysis was performed using the Relative Gain Array. RGA elements obtained from steady-state calculations can determine the controller configuration pairing. P only-PID controller parameters are determined by Ziegler-Nichols tuning method which detuned by Mc Avoy method. On the other hand, IMC controller parameter is determined by Rivera method. 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 will show 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 gave 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 indicating unstable trend and hard to controlled by P-only for level and PID for temperature. On the contrary in 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, using of IMC controller can be reference at non minimum phase control system.
Keywords: IMC Controller, PID Controller, Multivariable Process, Quadruple Tank.