Dual-mode model-based control of a process

The disclosed systems and techniques enable dual mode operation for model-based controllers in which the controllers are capable of operating in both (i) a constrained solution mode, and (ii) an unconstrained solution mode. The dual mode operation improves control because it enables the use of constrained solution mode operation when possible (constrained solution mode often enables superior control) and enables the use of unconstrained solution mode when constrained solution mode is not possible (e.g., when it is impossible to develop the constrained solution with the time available). This enables superior control when compared to typical model predictive control (MPC) controllers.