Slosh container system: Comparitive study of linear and non-linear sliding surfaces in sliding mode controller for slosh free motion

Liquid sloshing has been a challenging problem in different fields including launch vehicles and long range missiles applications. The coupled-slosh vehicle dynamics constitutes a highly non-linear second order under actuated system. The system is highly non-linear system, therefore controlling of slosh is highly complex. This paper presents a novel way of designing a Sliding Mode Controller (SMC) using non-linear sliding surface is used for slosh control in a container. Modeling of slosh dynamics is highly complex and nonlinear, the most commonly used equivalent mechanical model for lateral slosh dynamics is simple pendulum model. For linearizing the system, Partial Feedback Linearization technique has been used. In various literature SMC has been used as controller, the main issue of using SMC is chattering effect. For reducing the chattering effect in the control efforts the Boundary Layer Design technique is developed. Hence the proposed controller will provide better closed loop performance compared with conventional SMC (SMC with linear sliding surface). The proposed system is modeled and simulated using Matlab/Simulink to prove the effectiveness of SMC with nonlinear sliding surface compared with linear sliding surface.