US 6,662,583 B2Granted

Adaptive control for a cooling system

AssigneeCopeland Corporation

InventorsHung M. Pham, Abtar Singh, Jean-Luc M. Caillat, Mark Bass

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Abstract

A method and controller for a refrigerant pressure effecting component of a cooling system includes providing closed loop control over a pressure effecting component based on an error signal, performing a control algorithm that includes at least one programmably adjustable gain factor, and adaptably changing the programmably adjustable gain factor by periodically generating a new gain factor. More specifically, the system and method includes monitoring fluctuation in the error signal and generating a numeric value indicative of the percent fluctuation in the error signal over a predetermined period of time, then fuzzifying a numeric value to generate a set of fuzzy input values. A predetermined set of rules are applied to the fuzzy input values to generate a set of fuzzy output values, which are then defuzzified by a combining operation to yield the new gain factor.

Claims19

Dependent claims

A controller for a refrigerant pressure effecting component of a cooling system, comprising:

a control processor coupled to said pressure effecting component for providing closed loop control over said component based on an error signal;
said control processor including memory for storing first processing instructions for performing a control algorithm that includes at least one programmably adjustable gain factor;
said control processor including memory for storing second processing instructions for adaptively changing said programmably adjustable gain factor by periodically generating a new gain factor;
said second processing instructions causing said control processor to:
(a) monitor fluctuation in said error signal and generate a numeric value indicative of the percent fluctuation in said error signal over a predetermined time;
(b) fuzzify said numeric value by applying a membership function to generate a set of fuzzy input values indicative of degree of membership;
(c) apply a predetermined set of rules upon said fuzzy input values to generate a set of fuzzy output values, the predetermined set of rules reflecting the degree to which the gain factor associated with a given member of said membership function is to be changed;
and
(d) defuzzifying said fuzzy output values by a combining operation yielding said new gain factor.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 10/306,031Filed 27 Nov 2002 · division
Priority: 7 Jun 1995
Published: US 2003/0094004 A122 May 2003
Granted: 16 Dec 2003
Term ends: Not estimatedThe source records don’t support an estimate.

Classification34 codes

G05D 23/1909
Using an analogue comparing device: whose output amplitude can only take two discrete values
A47F 3/04
Show cases or show cabinets: air-conditioned, refrigerated
F04C 18/0215
Both members having co-operating elements in spiral form: where only one member is moving
F04C 27/005
Sealing arrangements in rotary-piston pumps specially adapted for elastic fluids: axial sealings for working fluid

Family

Application08/486,118Parent of this continuation-in-part · filed 7 Jun 1995
Application08/939,779Parent of this division · filed 29 Sep 1997
Application09/524,364Parent of this division · filed 14 Mar 2000
Application09/886,592Parent of this division · filed 21 Jun 2001
Application10/147,782Parent of this division · filed 16 May 2002
US 2003/0094004 A1Pre-grant publication · published 22 May 2003
US 6,499,305 B2Parent of this division
US 6,467,280 B2Parent of this division
US 6,408,635 B1Parent of this division
US 6,047,557 AParent of this division
Application08/939,779Parent of this continuation-in-part
US 5,741,120 AParent of this continuation-in-part
US 2001/0049942 A1Published application
US 2002/0178737 A1Published application
US 6,662,583 B2This patent

From the US filing history. Foreign family members aren’t listed.