Sliding Mode Observers with Application to Flexible Mode Control for Launch Vehicle Ares I

Dr. Yuri B. Shtessel

Department of Electrical and Computer Engineering
UAHuntsville

11 February 2011
218 Shelby Center
3:00 (Refreshements at 2:30)

Abstract

TSliding mode observers, including the ones based on higher order sliding mode control techniques, allow simultaneous state variable estimation and input reconstruction in dynamic systems. The sliding mode observation techniques are reviewed and used for improving the ARES I control system robustness to flexible body bending dynamics and propellant slosh modes while the actuator dynamics are taken into account as well. Effects of both flexible modes and both slosh modes on measurements and the coupling terms are estimated and compensated. The intensive simulation study demonstrated a stable accurate performance of the flight control system with the augmented simple PID controller. The compensated vehicle dynamics become stable without using notch filters.