US8027742B2
Active / In Force
US
⏱️ 2.1 years remaining
Fault detection systems and methods for self-optimizing heating, ventilation, and air conditioning controls
Assignee: Tyco Fire and Security GmbH
•
Filing: 2008-11-25
•
Granted: 2011-09-27
•
Expires: 2028-11-25
Abstract
Abstract A fault detection system for detecting a fault in a process system includes a first circuit configured to modify an input of the process system with a modifying signal. The fault detection system further includes a second circuit configured to receive an output from the process system and configured to determine whether the fault exists based on at least one of a reduction of a signal component and an unexpected transformation of the signal component, wherein the signal component corresponds to a function of the modifying signal.
Inventors
- 👤 John E. Seem
- 👤 Yaoyu Li
- 👤 Timothy Salsbury
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 17:40
CPC Classifications
G; G05; G05B; G05B13/00; G05B13/02; G05B5/00; G05B5/01; F; F24; F24F; F24F11/00; F24F11/30; F24F11/62; G05B13/0205; G05B13/024; G05D; G05D23/00; G05D23/19; F24F11/0001; F24F2011/0006
Claims Analysis
Total Claims: 7
Claim 1
Independent Claim
214 words
A method for detecting a fault in a process system, the method comprising: modifying an input of the process system with a modifying signal, wherein the modifying signal is a periodic signal; monitoring an output of the process system for a signal component corresponding to a function of the modifying signal, wherein the output provides a performance measure of the process system; optimizing the process system utilizing the output, wherein the optimization is conducted according to an extremum seeking control strategy, wherein the process system comprises an air handling unit configured to regulate temperature using a temperature regulator, wherein the air handling unit comprises a damper controlled by an actuator; controlling the temperature regulator; utilizing the extremum seeking control strategy to operate the actuator by providing a second control signal to the actuator, wherein the second control signal is the input of the process system modified by the modifying signal; and determining whether a fault exists based on at least one of a reduction of the signal component and an unexpected transformation of the signal component; wherein the process system is operated using a closed-loop system and is subject to feedback control and wherein the modifying signal comprises a dither signal provided to the input as a part of the extremum seeking control strategy.
Claim 2
Independent Claim
214 words
A method for detecting a fault in a process system, the method comprising: modifying an input of the process system with a modifying signal, wherein the modifying signal is a periodic signal; monitoring an output of the process system for a signal component corresponding to a function of the modifying signal, wherein the output provides a performance measure of the process system; optimizing the process system utilizing the output, wherein the optimization is conducted according to an extremum seeking control strategy, wherein the process system comprises an air handling unit configured to regulate temperature using a temperature regulator, wherein the air handling unit comprises a damper controlled by an actuator; controlling the temperature regulator; utilizing the extremum seeking control strategy to operate the actuator by providing a second control signal to the actuator, wherein the second control signal is the input of the process system modified by the modifying signal; and determining whether a fault exists based on at least one of a reduction of the signal component and an unexpected transformation of the signal component; wherein the process system is operated using a closed-loop system and is subject to feedback control and wherein the modifying signal comprises a dither signal provided to the input as a part of the extremum seeking control strategy.
Claim 3
Dependent Claim
22 words
The method of claim 1 , wherein the output is used by the feedback control and by the extremum seeking control strategy.
Claim 4
Dependent Claim
20 words
The method of claim 1 , wherein the dither signal is at least one of rectangular, triangular, ellipsoidal, and sinusoidal.
Claim 5
Dependent Claim
19 words
The method of claim 3 , further comprising: extracting the signal component from the output using a filter network.
Claim 6
Dependent Claim
60 words
The method of claim 4 , wherein determining that the fault exists based on at least one of a reduction of the signal component and an unexpected transformation of the signal component comprises at least one of: (a) comparing the signal component to a threshold power level; and (b) comparing a phase of the signal component to an expected phase.
Claim 7
Dependent Claim
86 words
The method of claim 5 , wherein monitoring for the output of the process system for a signal component corresponding to a function of the modifying signal comprises at least one of: (a) extracting the signal component from the output using a filter configured with a passband near that of an angular frequency component of the modifying signal; (b) conducting a frequency domain analysis of the output using a fast Fourier transform; and (c) conducting a time-domain analysis of the output using a zero-cross detection method.
References Cited (Backward Citations)
US2812141A
Cited
US3181791A
Cited
SU535103A1
Cited
US4114807A
Cited
US4182180A
Cited
US4199101A
Cited
US4319461A
Cited
US4257238A
Cited
US4607789A
Cited
US4512161A
Cited
US4558595A
Cited
US4876858A
Cited
US4942740A
Cited
JPS63231127A
Cited
JPH0462352A
Cited
US5461877A
Cited
US5414640A
Cited
US5251814A
Cited
US5351855A
Cited
US5355305A
Cited
US5506768A
Cited
US5568377A
Cited
US5346129A
Cited
US5467287A
Cited
US5555195A
Cited
US5682329A
Cited
US5590830A
Cited
US5791408A
Cited
US5675979A
Cited
JPH1047738A
Cited
US5769315A
Cited
US5867384A
Cited
US6122605A
Cited
US6269650B1
Cited
US6006142A
Cited
US6408228B1
Cited
US6477439B1
Cited
US6219590B1
Cited
US6161764A
Cited
US6389331B1
Cited
WO2000068744A1
Cited
US6594554B1
Cited
US6223544B1
Cited
US6296193B1
Cited
US6265843B1
Cited
US6326758B1
Cited
US6369716B1
Cited
US6415617B1
Cited
US6816811B2
Cited
US7050873B1
Cited
US7685830B2
Cited
US6973793B2
Cited
US20040164690A1
Cited
US6862540B1
Cited
US6937909B2
Cited
US20050006488A1
Cited
US20050040250A1
Cited
US7113890B2
Cited
US20080097651A1
Cited
US7124637B2
Cited
US7031880B1
Cited
US20060090467A1
Cited
US7434413B2
Cited
US20060259285A1
Cited
US20070023533A1
Cited
US7578734B2
Cited
US20080179408A1
Cited
US20080179409A1
Cited
US20080277486A1
Cited
WO2009012282A2
Cited
WO2009012269A2
Cited
US20100106328A1
Cited
US20100106331A1
Cited
US20090308941A1
Cited
US20100082161A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2014-09-26 | 2015-03-28 | 2015-09-27 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2018-09-26 | 2019-03-28 | 2019-09-27 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2022-09-26 | 2023-03-28 | 2023-09-27 | $7700.00 | Window Closed / Lapsed |