A STABILISING NONLINEAR PREDICTIVE CONTROL STRATEGY

In this paper a practical new approach to the topic of guarantee closed loop stability of constrained predictive controllers is proposed. The problem is addressed for the case when, due to disturbances, inadequate constraints, etc., the reference cannot be reached within the prediction horizon. The method combines the cancellation of modes at the end of the prediction horizon with a minimization of the distance to the controller set point. In this way, the proposed scheme assures stability even with open loop unstable processes while, at the same time, avoids the feasibility problems. The efficacy of the proposed approach is demonstrated through a nonlinear chemical reactor example.