(386d) Global Optimization of Stiff Dynamical Systems
AIChE Annual Meeting
2019
2019 AIChE Annual Meeting
Liaison Functions
AIChE Journal Futures: New Directions in Chemical Engineering Research (Invited Talks)
Tuesday, November 12, 2019 - 4:45pm to 5:10pm
In this talk, a new deterministic global optimization method is presented for nonlinear programming formulations constrained by stiff systems of ordinary differential equation (ODE) initial value problems (IVP). The examples arise from dynamic optimization problems exhibiting both fast and slow transient phenomena commonly encountered in model-based systems engineering applications. The proposed approach utilizes unconditionally-stable implicit integration methods to reformulate the ODE-constrained problem into a nonconvex nonlinear program with implicit functions embedded. This problem is then solved to global optimality in finite time using a spatial branch-and-bound framework utilizing convex/concave relaxations of implicit functions constructed by a method which fully exploits problem sparsity. The algorithms were implemented in the Julia programming within the EAGO.jl package and demonstrated on numerical examples with varying complexity relevant in process systems engineering. The developed methods enable the guaranteed global solution of dynamic optimization problems with stiff ODE-IVPs embedded.