Method of Connecting Different Layers of Optimization
AssigneeExxonMobil Research and Engineering Company
InventorsTod J. Peterson, William P. Snow, John R. Hind, Kiran R. Sheth
Life of this patent
Estimating the term…
Abstract
The present invention is a method for synchronizing multiple layers of constrained optimization with both layers having some common variables in a to processing plant. The layers of optimization can include Planning, Scheduling, Real-Time Optimization and Model Predictive Control.
Claims9
A method for synchronizing two different layers of constrained optimization, each layer having some common variables, which are jointly optimizing the operation of a processing plant by:
- a. identifying the set of active constraints and associated shadow values (cost sensitivities) in the upper optimization layer.
- b. finding a set of exact and/or approximate matching variables in the lower optimization layer that closely represent the set of upper level optimizer constraints,
- c. using the model from the lower level optimizer to solve for the economic inputs that push the process to the chosen set of lower level optimizer constraints, and
- d. identifying the variables which cannot be reached by the lower-level optimization using only economics, and fixing their values with numeric targets.
A method for comparing and validating the models of variables which exist in multiple optimization layers by calculating the weighted, normalized dot product between a vector of model sensitivities of a variable in an upper optimization layer and the vector of model sensitivities for the same variable in a lower optimization layer.
Dependencies are inferred from the claim text.