Nonlinear robust attitude controller for a satellite launch vehicle with fuel slosh dynamics

This paper deals with the attitude control problem of a satellite launch vehicle including slosh dynamics. The prominent sloshing modes are modeled by means of a single pendulum. In this work, a nonlinear robust higher order sliding mode controller is designed for the attitude stability as well as slosh attenuation of a launch vehicle and is compared with the existing classical sliding mode controller. Higher order sliding mode control is even more powerful as it can be applied to systems with an arbitrary relative degree and it can also reduce the chattering problem present in the classical sliding mode. This proposed design approach applied to a satellite launch vehicle is found to be robust to all parameter variations and uncertainties. Simulation results show the effectiveness of the proposed higher order sliding mode controller.