Linear embedding vs. direct nonlinear MPC schemes: a case study

A robust MPC strategy is described for solving set-point problems for a class of nonlinear systems subject pointwise-in-time input and/or state related constraints. The trajectories of the nonlinear system are embedded within those of a linear parameter varying (LPV) uncertain system so that the convex computational paradigm of the LMI optimization can be used. In this note, the main features of a convex robust linear MPC scheme, suitable for the embedding, are presented and it is contrasted, via a highly nonlinear example, with a direct nonlinear non-convex MPC scheme in terms of control performance and computational burdens.