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US5819188A
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Fault tolerant automatic control system utilizing analytic redundancy
Assignee: Dabulamanzi Holdings LLC
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Filing: 1997-03-18
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Granted: 1998-10-06
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Expires: 2017-03-18
Abstract
Abstract Method and apparatus for a fault tolerant automatic control system for a dynamic device having a sensor and a predetermined control algorithm include structure and steps for receiving a status signal from the sensor. Structure and steps are provided for transforming the sensor status signal and a predetermined reference signal into a linear time invariant coordinate system, generating a sensor estimate in the linear time invariant coordinate system based on the transformed sensor status signal and the transformed reference signal, transforming the sensor estimate into a physical coordinate system, detecting an error in the sensor status signal based on a comparison of the transformed sensor estimate and the sensor status signal, and reconfiguring the predetermined control algorithm based on the detected error. Preferably, the apparatus and method are implemented in an aircraft flight control system capable of detecting an aircraft sensor fault and reconfiguring the flight control program such that flight control surface actuators are commanded by ignoring or mitigating the failed sensor.
Inventors
- 👤 David W. Vos
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-08 14:49
CPC Classifications
G; G05; G05B; G05B9/00; G05B9/02; G05B23/00; G05B23/02; G05B23/0205; G05B23/0259; G05B23/0286; G05B9/03; G05D; G05D1/00; G05D1/0055; G05D1/0077
Claims Analysis
Total Claims: 23
Claim 1
Independent Claim
103 words
A method of determining the operational status of a parameter dependent control system for controlling a dynamic device, said method comprising the steps of: receiving a current state signal representing a current state of the device and a control signal for effecting control of the device; transforming the current state signal and the control signal to a linear time invariant system; estimating an expected behavior of the device using the transformed current state signal and the transformed control signal; and determining the operational status of the control system by comparing the expected behavior of the device to the actual behavior of the device.
Claim 2
Independent Claim
103 words
A method of determining the operational status of a parameter dependent control system for controlling a dynamic device, said method comprising the steps of: receiving a current state signal representing a current state of the device and a control signal for effecting control of the device; transforming the current state signal and the control signal to a linear time invariant system; estimating an expected behavior of the device using the transformed current state signal and the transformed control signal; and determining the operational status of the control system by comparing the expected behavior of the device to the actual behavior of the device.
Claim 3
Dependent Claim
66 words
A method according to claim 1 wherein said estimating step comprises the step of outputting an estimated signal corresponding to the expected behavior, and wherein said determining step comprises the steps of: obtaining a status signal corresponding to the actual behavior of the device; subtracting the estimated signal from status signal to obtain a difference signal; and comparing the difference signal to a predetermined threshold value.
Claim 4
Dependent Claim
37 words
A method according to claim 2 wherein said determining step further comprises a step of generating a failure signal indicating the failure of a system component when the difference signal is greater than the predetermined threshold value.
Claim 5
Dependent Claim
35 words
A method according to claim 3 wherein the control system has a predetermined control algorithm and wherein said method further comprises a step of reconfiguring the control algorithm in response to the generated failure signal.
Claim 6
Dependent Claim
32 words
A method according to claim 4 wherein, when the failure signal corresponds to a failed sensor, said reconfiguring step comprises zeroing a term in the control algorithm corresponding to the failed sensor.
Claim 7
Dependent Claim
36 words
A method according to claim 4 wherein, when the failure signal corresponds to a failed sensor, said reconfiguring step comprises using an integrated rate of change signal in place of a signal from the failed sensor.
Claim 8
Dependent Claim
39 words
A method according to claim 4 wherein, when the failure signal corresponds to a failed actuator, said reconfiguring step comprises adjusting the control algorithm so that at least one other actuator is controlled to compensate for the failed actuator.
Claim 9
Dependent Claim
115 words
A parameter dependent control system for controlling a dynamic device, said system comprising: receiving means for receiving a current state signal representing a current state of the device and a control signal for effecting control of the device; transforming means for transforming the current state signal and the control signal to a linear time invariant system; estimating means for estimating an expected behavior of the device using the transformed current state signal and the transformed control signal and for generating an estimate signal corresponding to the expected behavior; and determining means for determining the operational status of the control system by comparing the expected behavior of the device to the actual behavior of the device.
Claim 10
Dependent Claim
115 words
A parameter dependent control system for controlling a dynamic device, said system comprising: receiving means for receiving a current state signal representing a current state of the device and a control signal for effecting control of the device; transforming means for transforming the current state signal and the control signal to a linear time invariant system; estimating means for estimating an expected behavior of the device using the transformed current state signal and the transformed control signal and for generating an estimate signal corresponding to the expected behavior; and determining means for determining the operational status of the control system by comparing the expected behavior of the device to the actual behavior of the device.
Claim 11
Dependent Claim
54 words
A system according to claim 1 wherein said determining means comprises: receiving means for receiving a status signal corresponding to the actual behavior of the device; subtraction means for subtracting the estimated signal from status signal to obtain a difference signal; and comparison means for comparing the difference signal to a predetermined threshold value.
Claim 12
Dependent Claim
37 words
A system according to claim 9 wherein said determining means further comprises generation means for generating a failure signal indicating the failure of a system component when the difference signal is greater than the predetermined threshold value.
Claim 13
Dependent Claim
35 words
A system according to claim 10 wherein the control system has a predetermined control algorithm and wherein said system further comprises reconfiguration means for reconfiguring the control algorithm in response to the generated failure signal.
Claim 14
Dependent Claim
31 words
A system according to claim 11 wherein, when the failure signal corresponds to a failed sensor, said reconfiguration means zeroes a term in the control algorithm corresponding to the failed sensor.
Claim 15
Dependent Claim
35 words
A system according to claim 11 wherein, when the failure signal corresponds to a failed sensor, said reconfiguration means uses an integrated rate of change signal in place of a signal from the failed sensor.
Claim 16
Dependent Claim
38 words
A system according to claim 11 wherein, when the failure signal corresponds to a failed actuator, said reconfiguration means adjusts the control algorithm so that at least one other actuator is controlled to compensate for the failed actuator.
Claim 17
Dependent Claim
26 words
A system according to claim 11 wherein said transforming means, said estimating means, said determining means, and said reconfiguration means are integrated in a single processor.
Claim 18
Dependent Claim
109 words
Apparatus for detecting a failure in a flight control device, comprising: processing structure for (i) receiving a time-varying status signal from the flight control device, (ii) providing a reference signal corresponding to the flight control device, (iii) transforming both the status signal and the reference signal to a linear time invariant coordinate system, (iv) calculating a flight control device estimated signal based on the transformed status signal and the transformed reference signal, (v) transforming the calculated estimate signal into a physical coordinate system, and (vi) detecting an error in the flight control device when a difference between the transformed estimate signal and the status signal exceeds a predetermined threshold.
Claim 19
Dependent Claim
109 words
Apparatus for detecting a failure in a flight control device, comprising: processing structure for (i) receiving a time-varying status signal from the flight control device, (ii) providing a reference signal corresponding to the flight control device, (iii) transforming both the status signal and the reference signal to a linear time invariant coordinate system, (iv) calculating a flight control device estimated signal based on the transformed status signal and the transformed reference signal, (v) transforming the calculated estimate signal into a physical coordinate system, and (vi) detecting an error in the flight control device when a difference between the transformed estimate signal and the status signal exceeds a predetermined threshold.
Claim 20
Dependent Claim
36 words
Apparatus according to claim 16, wherein said processing structure includes a predetermined control algorithm which utilizes said flight control device status signal, and wherein said processing structure reconfigures said control algorithm based on the detected error.
Claim 21
Dependent Claim
24 words
Apparatus according to claim 16, wherein said processing structure changes an operating characteristic of a second flight control device based on the detected error.
Claim 22
Dependent Claim
18 words
Apparatus according to claim 16, wherein said processing structure outputs an error signal indicative of the detected error.
Claim 23
Dependent Claim
23 words
A computer-readable medium encoded with a data structure which causes said processing structure to perform the functions (i) through (vi) of claim 16.
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USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 2001-10-05 | 2002-04-06 | 2002-10-06 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2005-10-05 | 2006-04-06 | 2006-10-06 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2009-10-05 | 2010-04-06 | 2010-10-06 | $7700.00 | Window Closed / Lapsed |