Geometric Mechanics Based Nonlinear Model Predictive Spacecraft Attitude Control with Reaction Wheels

Abstract

This paper develops a nonlinear model predictive controller for constrained attitude maneuvering of a fully actuated spacecraft with reaction wheels. In the proposed control algorithm, a Lie group variational integrator is used as a predictive model. The nonlinear model predictive control problem is formulated in the form of a discrete-time optimal control problem over each prediction horizon, and a numerical solver is used to solve the necessary conditions for optimality for this discrete-time optimal control problem. The numerical solver uses the indirect single shooting method. The control constraints and exclusion zone constraints are handled using the exterior penalty function approach. Simulation results are presented and compared with the case of a fully actuated spacecraft without reaction wheels. The nonlinear model predictive controller is shown to provide a large domain of attraction.