2 research outputs found
Finite-Time Second-Order Sliding Mode Controllers for Spacecraft Attitude Tracking
The attitude tracking control problem of a spacecraft nonlinear system with
external disturbances and inertia uncertainties is studied. Two robust attitude
tracking controllers based on finite-time second-order sliding mode control
schemes are proposed to solve this problem. For the first controller, smooth
super twisting control is applied to quaternion-based spacecraft-attitude-tracking
maneuvers. The second controller is developed by adding linear correction
terms to the first super twisting control algorithm in order to improve the dynamic
performance of the closed-loop system. Both controllers are continuous
and, therefore, chattering free. The concepts of a strong Lyapunov function are
employed to ensure a finite-time convergence property of the proposed controllers.
Theoretical analysis shows that the resulting control laws have strong
robustness and disturbance attenuation ability. Numerical simulations are also
given to demonstrate the performance of the proposed control laws