Technique to improve paper machine cross-directional model predictive control performance by creating a measurement profile reference trajectory

US10174456B2 · kind B2 · utility

Assignee

• Honeywell Limited · US

Inventors

• Johan U. Backstrom · North Vancouver, CA
• Michael Forbes · North Vancouver, CA

Key dates

• Filing date: Sep 23, 2016
• Grant date: Jan 8, 2019
• Expiry date: Apr 22, 2037

Classification

• Technology area (CPC G): Physics
• CPC primary: G05B2219/40148
• WIPO field: Control
• WIPO sector: Instruments

Abstract

Controlling a multiple-array, sheetmaking cross-directional process with a multivariable model predictive controller (MPC) employs a cost function incorporating a prediction horizon. The MPC provides a measurement profile target reference trajectory over the prediction horizon of the MPC cost function. Improved CD-MPC performance is achieved by employing a measurement profile target reference trajectory over the prediction horizon in the MPC cost function. A series of target profiles creates a reference trajectory to bring the cross-direction measurements smoothly from their current profile to the final target. By carefully designing the reference trajectory, the CD-MPC exhibits a good measurement response without aggressive control action. The current measurement target profile can be filtered through a first order plus deadtime process at each controller update and repeating the filter operation once for each step of the MPC prediction horizon generates a full reference trajectory for the profile.