Nonsingular Finite-Time Convergent Control for Spacecraft Rendezvous and Docking

Abstract

This paper deals with the problem of relative position control of the chaser spacecraft during rendezvous using sliding mode control, wherein the time of operation plays a critical role in the success of mission. Conventional sliding mode controller ensures only asymptotic convergence. We propose the application of a controller based on terminal sliding mode that guarantees the finite time convergence of controlled variable to achieve the mission successfully. The proposed controller may encounter a singularity for some scenarios in real applications. To achieve finite time convergent controller enabling the spacecraft for rendezvous mission while avoiding any singularities, we also propose a controller based on nonsingular terminal sliding mode control. We validated the proposed techniques using numerical simulations and found them to be satisfactory.