Input-to-State Stable Attitude Control

Simulation about Proportional-plus-Derivative (PD)-type control laws which are not generally robust as regards to bounded disturbances and provide a sufficient condition for nonlinear type control laws to render system semiglobally input-to-state-stable (ISS) was proposed. The main concept of ISS is to characterize the stability of system under bounded disturbances. The Clayey-Rodriguez parameterization suffered from lack of robustness with respect to bounded disturbances from simple PD type attitude control. A nonlinear control law was proposed with sufficient condition under which the closed-loop system was semiglobally ISS. Hence, it was constructed in a way that any given restriction on the initial state and disturbance input, for large design control gains that can render the system input-to-state stable within the stated restrictions.