Robust Control Design for a Nanosat Launch Vehicle

The attitude control of a launch vehicle is a challenging task due to the dramatically varied vehicle dynamics along a flight path. The objective of this paper is to design robust controllers for a nanosat launch vehicle developed by California Launch Vehicle Education Initiative at California State University Long Beach. In order to control the rocket along a trajectory ascending through the earth’s atmosphere, a set of operating points at different times along the flight path are selected, the corresponding dynamics models of the rocket are obtained via linearization, and a robust H_∞ controller is designed for each operating point. Simulations are conducted in Matlab/Simulink to verify if the proposed control law stabilizes the inherent, unstable pitching motions of the vehicle at different times.