Spacecraft attitude tracking for space debris removal using adaptive fuzzy sliding mode control

Abstract

In this paper, the problem of attitude tracking control for clean platform, with no prior knowledge about the bounds of the parametric uncertainties and external disturbances, in the process of space debris removal is investigated. We proposed a robust adaptive control strategy, which is based on the coupling of the fuzzy logic system (FLS) with sliding mode control (SMC). First, a desired attitude solution model for the space debris removal is developed, and the error attitude dynamics equation of clean platform is formulated. Second, a sliding mode controller is designed due to its appreciable features to the uncertainties and disturbances. On this basis, a FLS is employed to approximate the unknown system functions, and the approximation errors are eliminated using adaptive algorithm. Meanwhile, the control gains of the switching control, being constant in the conventional SMC approach, are adjusted adaptively by fuzzy logic inference techniques in order to reduce the chattering phenomenon. The global stability of the closed-loop system is proven by the Lyapunov stability theorem. Finally, detailed numerical simulations are carried out to verify the robustness and effectiveness of the proposed adaptive fuzzy sliding mode control (AFSMC) approach. The simulation results show that the proposed AFSMC approach can ensure that the spacecraft exactly tracking the desired attitude in presence of inertial uncertainties and external disturbances and effectively reduce the chattering against to the conventional SMC approach.