Process safeness index: Its definition and use in economic model predictive control to ensure process operational safety

Abstract

In this work, we propose initial steps in the first systems safety approach that coordinates the control and safety systems through a common metric (a Safeness Index) and develop a controller formulation that incorporates this index. Specifically, this work presents an economic model predictive control (EMPC) scheme that utilizes a Safeness Index function as a hard constraint to define a safe region of operation termed the safety zone. Under the proposed EMPC, the closed-loop state of a nonlinear process can be guaranteed to enter the safety zone in finite time while maximizing the process economics. The proposed design is demonstrated using a chemical process example.