  In this paper, a control scheme is developed based on an input constrained
Model Predictive Controller (MPC) and the idea of modifying the reference
command to enforce constraints, usual of Reference Governors (RG). The proposed
scheme, referred to as the RGMPC, requires optimization for MPC with input
constraints for which fast algorithms exist, and can handle (possibly
nonlinear) state and input constraints. Conditions are given that ensure
recursive feasibility of the RGMPC scheme and finite-time convergence of the
modified command to the the desired reference command. Simulation results for a
spacecraft rendezvous maneuver with linear and nonlinear constraints
demonstrate that the RGMPC scheme has lower average computational time as
compared to state and input constrained MPC with similar performance.
