Backstepping control for a quadruple tank process based on adaptive observer

This paper is about control of hydrographic process. A new output control scheme is developed, which combine a nonlinear backstepping control with an adaptive high gain observer. We consider the nonlinear MIMO class of systems, which include the model of our hydrographic process. The main objective is to automate the control of pumps for a successful and safe manner in order to keeps the levels of the bottoms tanks to specific references. Only two sensors are available to measure the liquid level in both bottom tanks and the other process´s states and some parameters are assumed unavailable. An adaptive high gain observer is used as solution for estimating conjointly liquid levels for high tanks and system parameter´s. Thereafter, the estimate variables are incorporated in the Backstepping controller in order to generate the control signal for both motopump that ensuring the tracking objective.