Robust control of near-space vehicles with input backlash-like hysteresis

Abstract

In this article, robust attitude control schemes are proposed for the near-space vehicle with the backlash-like hysteresis and the time-varying unknown disturbance using backstepping technique. In the robust attitude control design, the backlash-like hysteresis is described by a dynamic equation which is decomposed as a linear term and a nonlinear term. To handle the nonlinear term in the dynamic equation of the backlash-like hysteresis and the time-varying unknown disturbance, they are treated as a compounded disturbance and the nonlinear disturbance observer is designed to estimate them. Based on the developed nonlinear disturbance observer, the robust backstepping attitude control is firstly developed for the near-space vehicle. Then, the robust sliding mode attitude control scheme is presented for the near-space vehicle to further enhance the robust attitude control performance. The convergence of all closed-loop signals is rigorously proved via Lyapunov analysis method under the developed robust attitude control schemes. Finally, simulation results are presented to illustrate the effectiveness of the proposed attitude control approaches.