Nonlinear Gain Scheduled Controller For A Sphere Liquid Tank

In this paper, we develop a gain-scheduled controller for a nonlinear plant of the sphere liquid tank. The proposed strategy is based on linearization of the nonlinear state equation around selected operating points. This methodology allows to apply any linear control design method. In particular, we discuss a polynomial method to achieve desired stability and performance requirements. Following this idea, both 1DOF and 2DOF control configurations are considered. The linear design methods are applied at each operating point in order to arrive at a set of linear control laws. Additionally, the parameters of the resulting family of linear controllers are scheduled as functions of reference variable, resulting in a single controller. Nonlocal performance of gain scheduled controller for the nonlinear model is checked by mathematical simulation.