US 8,078,289 B2 · Model predictive control with variable trajectory sharing

Abstract

One or more techniques are provided for the sharing of variable trajectories between multiple controllers in a control system. In general, the present technique is based upon the sharing of predicted desired variable trajectories between multiple controllers requiring a common input variable. In one embodiment, a common input variable is shared between two controllers, wherein one controller is tuned to have dominant control with regard to the shared variable. Each controller determines and communicates their own desired trajectory for the shared variable to the other controller and in doing so, the constraints associated with each controller are shared and honored by the other controller. Based on the communicated trajectories, the dominant controller may exercise control over the shared variable, thus improving overall process control.

Claims26

Dependent claims

In a process control system having a plurality of controllers, wherein two or more controllers share a common process variable, a method comprising:

determining for each of the two or more controllers a respective variable trajectory for a shared variable;
communicating the determined respective variable trajectories between the two or more controllers;
and
controlling the shared variable based upon the determined respective variable trajectories.

1 more element

A process control system comprising:

a plurality of processing units configured to collectively carry out a process;
one or more sensors configured to sense one or more process variables;
a plurality of controllers, each of the controllers being configured to control one or more of the plurality of processing units, wherein each of the controllers comprises:
input interface circuitry configured to receive variables sensed by the one or more sensors;
memory circuitry configured to store one or more control algorithms;
communication circuitry configured to communicate data between the plurality of controllers;
processing circuitry coupled to the memory circuitry and configured to execute the one or more control algorithms to determine control functions;
and
output interface circuitry configured to output signals configured to drive one or more actuators based on the control functions determined by the processing circuitry;
wherein two or more controllers are configured to control one or more of the plurality of processing units based at least partially on a shared process variable, and wherein each of the two or more controllers sharing the shared process variable is further configured to determine for each of the two or more controllers a respective variable trajectory for the shared process variable, communicate the determined respective variable trajectories to the other controllers of the two or more controllers using the communication circuitry, and control the shared process variable based upon communicated respective variable trajectories.

7 more elements

Dependencies are inferred from the claim text.

Model predictive control with variable trajectory sharing

Life of this patent

Model predictive control with variable trajectory sharing

Life of this patent

Abstract

Claims26