Dynamic modeling and model mismatch of coupled water tanks system

For the inertial, delayed and nonlinear characters of the liquid level system of coupled water tanks, many actual industrial objects can be abstracted into water tanks models to describe their features. This paper studied coupled water tanks, built its mechanism model on the basis of hydrodynamics theory, got transfer function model at the quiescent point in the manner of linearization, and proved the validity of the model in different working point. Besides, this paper also identified the object model parameters of water tanks system depending on the input and output data, set up state space model of the system applying subspace modeling methods, and verified the real validity of the model by simulation. In view of the model change led by condition fluctuation, this paper designed experiment to change the water tanks model parameters, defined model evaluation index to decide the mismatch of the model, and when the model mismatched, rebuilt a new model to track the real system. The study will have a guiding significance for dynamically modeling of coupled water tanks system and other similar systems and their model mismatch evaluation.