Modelling and identification of a coupled sextuple water tank system

This paper presents the modelling and identification procedure applied to a coupled, non-minimum phase system consisting of six water tanks. This process is composed of three inter-connected sub-systems coupled through the inputs. Using the process description, the theoretical nonlinear model was derived and linearised around a chosen operating point. After that, a three part experiment was conducted on the sextuple plant from Quanser in which one of the system's inputs was varied while the others remained constant. The experimental data was used to compute the system's static characteristic which describes the output variation limits for different input values. Then, the dynamic characteristic was used to analyse the system evolution in transient time to provide insight knowledge about the model orders required in the parametric identification. The results obtained clearly show that the computed linear model proper characterizes the dynamics of the real process and can be further used in simulations.