Enhanced ISS nominal MPC based on constraint tightening for constrained linear systems

This paper presents a new robust MPC formulation based on nominal predictions that improves other popular robust MPC formulations such as Chisci et al. (2001); Mayne et al. (2005). As in Chisci et al. (2001), the proposed controller ensures robust feasibility by means of tighter constraints, however, the condition on the terminal constraint has been notably relaxed, leading to less conservative controllers. Another remarkable property is that the calculation of (an approximation of) the minimum robust positively invariant set is not required, which makes its design more simple than the tube-based MPC proposed in Mayne et al. (2005). Furthermore, input-to-state stability of the closed loop system is proved. These properties are demonstrated in an illustrative example.