Drift Counteraction and Control of Downsized and Underactuated Systems: What MPC Has to Offer?

Motivated by practical applications, the paper highlights MPC formulations suitable for counteracting system drift and the effects of large measured disturbances/set-point changes, and for overcoming limitations of underactuation. For drift counteraction, where the objective is to maximize the time or yield until the system trajectory exits a prescribed set, defined by system safety constraints, operating limits and/or efficiency requirements, MPC, based on mixed integer or conventional linear programming, can lead to effective solutions for higher order systems than possible with dynamic programming and value iterations based methods. Such solutions can have broad applicability including for fuel optimal Geostationary Orbit (GEO) station keeping, spacecraft Low Earth Orbit (LEO) maintenance, underactuated spacecraft attitude control, hybrid electric propulsion energy management, glider flight management, and the development of driving policies for adaptive cruise control and autonomous driving. The paper also highlights the capability of MPC to achieve non-smooth local stabilization of underactuated systems that can be exploited for attitude control of underactuated spacecraft with reaction wheel failures. Related results for systems that cannot be globally stabilized by continuous feedback are also mentioned. Finally, opportunities to handle large load and set-point changes with reference governors are discussed.