Finite-time stabilization of the NASA CEV reaction control system with actuator saturation and by position measurements

This paper studies the problem of finite-time stabilization of planar systems whose control input is subjected to saturation caused by actuator limitations. Finite-time control deals with convergence within a finite settling time and therefore guarantees the performance of a nonlinear system within a specific time T. In the literature, most of the existing finite-time convergent controllers are unbounded and therefore are not implementable for a system with actuator saturation. In this paper, we propose a design method of the finite-time convergent controller which is bounded by a prior given bound. We show that the controller, together with a finite-time convergent observer, will effectively move the system to the origin in finite time. As an example of an application of our controller, we will apply our results on the NASA Crew Exploration Vehicle reaction control system thrusters to demonstrate the effectiveness of the proposed controller for use on a system with saturation constraints. Our results indicate that finite-time controllers would be an ideal candidate for use on the Crew Exploration Vehicle reaction control system thrusters.