US 5,548,528 AGranted

Virtual continuous emission monitoring system

AssigneePavilion Technologies, Inc.

InventorsJames D. Keeler, John P. Havener, Devendra Godbole, Ralph B. Ferguson

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Abstract

A continuous emission monitoring system for a manufacturing plant (10) includes a control system (16) which has associated therewith a virtual sensor network (18). The network (18) is a predictive network that receives as inputs both control values to the plant (10) and also sensor values. The network (18) is then operable to map the inputs through a stored representation of the plant (10) to output a predicted pollutant sensor level. This predicted pollutant sensor level is essentially the prediction of an actual pollutant sensor level that can be measured by a pollutant sensor (14). The network (18) therefore is a substitute for the pollutant sensor (14), thus providing a virtual sensor. The sensor values from the plant (10) are first processed through a sensor validation system (22). The sensor validation system (22) is operable to determine which of the sensors falls outside of acceptable limits and then substitutes therefor a predicted output, such that the inputs to the virtual sensor network (18) are within acceptable limits.

Claims11

Dependent claims

A method for monitoring select output parameters in a manufacturing plant that are generated as a byproduct of the operation of the plant, the manufacturing plant having controls operating in response to received control values to alter the operation of the plant, and sensors to measure the operating parameters of the plant and output associated sensor values, comprising the steps of:

determining at least once the level of the select output parameters output by the plant and the associated control values to the plant in addition to the associated sensor values, the step of determining at least once utilizing a predetermined determination process;
measuring on a substantially frequent basis the control values to the plant and the sensor values output by the sensors;
storing a representation of the plant in association with the determination process in a virtual sensor predictive network having as an output a predicted select output parameter level that corresponds to the actual select output parameter level determined by the determination process to be output by the manufacturing plant, the control values of the plant and the sensor values of the plant comprising inputs to the virtual sensor predictive network, the stored representation learned from the determined output parameter level by the determination process, the control values and the sensor values, the virtual sensor predictive network operable to be trained upon the determined level of the select output parameters, the measured control values and the sensor values to generate the stored representation;
and
generating an error when the predicted output parameter level exceeds a predetermined threshold.

2 more elements

A system for monitoring select output parameters in a manufacturing plant that are generated as a by-product of the operation of the plant, the manufacturing plant having controls operating in response to received control values to alter the operation of the plant and sensors to measure the operating parameters of the plant and output associated sensor values, comprising:

a system for measuring at least once the select operating parameters emitted by the plant and the associated control values to the plant with the associated sensor values, the determining system utilizing a predetermined determination process;
a plant information system for measuring the control values to the plant and the sensor values of the plant;
a virtual sensor predictive network for storing a representation of the plant in association with the determination process and having as an output a selected operating parameter level that corresponds to the actual select operating parameter level determined by the determination process to be output by the manufacturing plant, the control values of the plant and the sensor values of the plant from said plant information system comprising inputs to said virtual sensor predictive network, the stored representation learned from the determined select operating parameter level as determined by the determination process, the control values and the sensor values, said virtual sensor predictive network operable to be trained upon the determined level of the select operating parameters, the measured control values and the sensor values to generate the stored representation;
and
an error generator for generating an error when the predicted pollutant level exceeds a predetermined threshold.

2 more elements

Dependencies are inferred from the claim text.

Facts

Application: 08/380,062Filed 30 Jan 1995 · continuation
Priority: 5 Aug 1993
Granted: 20 Aug 1996
Term ends: Not estimatedThe source records don’t support an estimate.

Classification11 codes

F02D 41/1401
Introducing closed-loop corrections: characterised by the control or regulation method
G01N 33/0034
Comprising two or more sensors, e.g. a sensor array: comprising neural networks or related mathematical techniques
G01N 33/0075
Control unit therefor: for multiple spatially distributed sensors, e.g. for environmental monitoring
G05B 13/027
The criterion being a learning criterion: using neural networks only