Safe Tracking Control of Nonlinear Systems Based on Optimal Control for Low-Fidelity Models

This letter considers the control of discrete-time nonlinear systems subject to output constraints. A control strategy is proposed which combines an input sequence generator, based on solving an optimal control problem for a lower-fidelity linear model, with a prediction-based supervisory scheme that adjusts the reference command to ensure constraints satisfaction for the original nonlinear system. Under suitable assumptions, recursive feasibility, finite-time convergence of the applied reference command to a desired strictly steady state admissible reference command and asymptotic convergence of the state to the associated steady state are shown. Simulation results illustrate the proposed methodology for a highly nonlinear spacecraft control maneuver.