US5268644A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Fault detection and isolation in automotive wiring harness by time-domain reflectometry
Assignee: NATION CENTER FOR MANUFACTURING SCIENCES (NCMS)
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Filing: 1990-04-03
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Granted: 1993-12-07
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Expires: 2010-04-03
Abstract
Abstract An automotive electrical system including a wiring harness incorporates the dedicated test line passing through critical connectors and components for allowing detection and isolation of improperly connected connectors. The dedicated test line can feed through expansion connectors, termination connectors, and junction blocks. Connector fault detection and isolation is achieved using time-domain reflectometry after final assembly, during vehicle servicing, or on-board during vehicle usage. A large number of expensive and inconvenient vehicle quits and tow-in's are avoided that would otherwise occur.
Inventors
- 👤 David J. Klassen
- 👤 Edward G. Anderson
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-28 02:16
CPC Classifications
G; G01; G01R; G01R31/00; G01R31/005; G01R31/006; G01R31/08; G01R31/11
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
176 words
An automotive electrical system comprising: a plurality of electrical components including at least one termination device; a wiring harness system interconnecting said electrical components and including a plurality of harness conductors and a plurality of connectors, one of said connectors being a termination connector connected to said termination device, said wiring harness system including a dedicated test line provided by a termination conductor disposed in said termination connector and provided by more than one of said harness conductors, said dedicated test line extending between a test point and a test line termination; driving means connected to said test point for applying a test signal pulse to said dedicated test line at said test point; receiving means connected to said test point for sensing a resulting time-delayed signal at said test point in response to said test signal; and time measuring means connected to said driving means and said receiving means for measuring a time period between the application of said test signal pulse and the reception of said resulting signal as a reflection of said pulse.
Claim 2
Dependent Claim
176 words
An automotive electrical system comprising: a plurality of electrical components including at least one termination device; a wiring harness system interconnecting said electrical components and including a plurality of harness conductors and a plurality of connectors, one of said connectors being a termination connector connected to said termination device, said wiring harness system including a dedicated test line provided by a termination conductor disposed in said termination connector and provided by more than one of said harness conductors, said dedicated test line extending between a test point and a test line termination; driving means connected to said test point for applying a test signal pulse to said dedicated test line at said test point; receiving means connected to said test point for sensing a resulting time-delayed signal at said test point in response to said test signal; and time measuring means connected to said driving means and said receiving means for measuring a time period between the application of said test signal pulse and the reception of said resulting signal as a reflection of said pulse.
Claim 3
Dependent Claim
27 words
The electrical system of claim 1 wherein said dedicated test line is comprised of electrical harness conductors and wherein said test signal pulse is an electrical signal.
Claim 4
Dependent Claim
27 words
The electrical system of claim 1 wherein said dedicated test line is comprised of optical harness conductors and wherein said test signal pulse is an optical signal.
Claim 5
Dependent Claim
56 words
The electrical system of claim 1 further comprising signal measuring means connected to said driving means and said receiving means for measuring the magnitude of a reflected signal during a time period determined by said time measuring means and corresponding to the impedance of said dedicated test line at the location of one of said connectors.
Claim 6
Independent Claim
171 words
A method for isolating a fault in the interconnection of an automotive electrical system, said method comprising the steps of: providing a plurality of electrical components including at least one termination device; interconnecting said electrical components using a wiring harness system including a plurality of harness conductors and a plurality of connectors, one of said connectors being a termination connector connected to said termination device; providing a dedicated test line in said wiring harness system including a termination conductor disposed in said termination connector, said dedicated test line further including more than one of said harness conductors; providing a test point at one end of said dedicated test line and a test line termination at the opposite end of said dedicated test line; injecting a test signal pulse at said test point; and measuring a time delay for a reflection of said test signal pulse to arrive at said test point following the injection of said test signal pulse, such reflection corresponding to an interconnection fault or said test line termination.
Claim 7
Independent Claim
171 words
A method for isolating a fault in the interconnection of an automotive electrical system, said method comprising the steps of: providing a plurality of electrical components including at least one termination device; interconnecting said electrical components using a wiring harness system including a plurality of harness conductors and a plurality of connectors, one of said connectors being a termination connector connected to said termination device; providing a dedicated test line in said wiring harness system including a termination conductor disposed in said termination connector, said dedicated test line further including more than one of said harness conductors; providing a test point at one end of said dedicated test line and a test line termination at the opposite end of said dedicated test line; injecting a test signal pulse at said test point; and measuring a time delay for a reflection of said test signal pulse to arrive at said test point following the injection of said test signal pulse, such reflection corresponding to an interconnection fault or said test line termination.
Claim 8
Dependent Claim
23 words
The method of claim 5 wherein said dedicated test line is comprised of electrical conductors, said test signal pulse being an electrical pulse.
Claim 9
Dependent Claim
23 words
The method of claim 5 wherein said dedicated test line is comprised of optical conductors, said test signal pulse being an optical pulse.
Claim 10
Dependent Claim
27 words
The method of claim 5 wherein said dedicated test line follows a path including termination connectors for a plurality of critical electrical components in said electrical system.
Claim 11
Dependent Claim
34 words
The method of claim 5 further comprising the step of comparing the measured time delay to known time delays corresponding to each connector in said electrical system to identify the location of a fault.
Claim 12
Dependent Claim
48 words
The method of claim 5 further comprising the steps of: repeating said injecting and measuring steps at a later time; comparing the results from said measuring step for different times; and predicting a failure of said electrical system in response to an unequal comparison in said comparing step.
Claim 13
Independent Claim
171 words
A method for isolating a fault in the interconnection of an automotive electrical system, said method comprising the steps of: providing a plurality of electrical components including at least one termination device; interconnecting said electrical components using a wiring harness system including a plurality of harness conductors and a plurality of connectors, one of said connectors being a termination connector connected to said termination device; providing a dedicated test line in said wiring harness system including a termination conductor disposed in said termination connector, said dedicated test line further including more than one of said harness conductors; providing a test point at one end of said dedicated test line; injecting a test signal pulse at said test point; determining a time slot corresponding to an arrival time of a reflection of said test signal pulse at said test point from a selected one of said plurality of connectors; and measuring a magnitude of said reflection during said time slot to indicate the proper interconnection of said selected one of said connectors.
Claim 14
Independent Claim
171 words
A method for isolating a fault in the interconnection of an automotive electrical system, said method comprising the steps of: providing a plurality of electrical components including at least one termination device; interconnecting said electrical components using a wiring harness system including a plurality of harness conductors and a plurality of connectors, one of said connectors being a termination connector connected to said termination device; providing a dedicated test line in said wiring harness system including a termination conductor disposed in said termination connector, said dedicated test line further including more than one of said harness conductors; providing a test point at one end of said dedicated test line; injecting a test signal pulse at said test point; determining a time slot corresponding to an arrival time of a reflection of said test signal pulse at said test point from a selected one of said plurality of connectors; and measuring a magnitude of said reflection during said time slot to indicate the proper interconnection of said selected one of said connectors.
Claim 15
Dependent Claim
58 words
The method of claim 11 further comprising the steps of: repeating said injecting, determining, and measuring steps at a later time for said selected one of said connectors; comparing said measured magnitude for each of said times; and indicating an impending failure of said selected one of said connectors when said measured magnitude changes by a predetermine magnitude.
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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) | 1996-12-06 | 1997-06-07 | 1997-12-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 2000-12-06 | 2001-06-07 | 2001-12-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2004-12-06 | 2005-06-07 | 2005-12-07 | $7700.00 | Window Closed / Lapsed |