Fault identification system
First Claim
1. A system for identifying faults in an electrical circuit intended to provide a plurality of outputs, each output being in response to at least one predetermined set of circuit conditions, the system comprisinga) means storing data describing individual components of an electrical circuit and interconnections at circuit nodes between said components that together define the topology of the electrical circuit,b) means for inputting data to the system identifying a fault symptom indicating that, for one predetermined set of said circuit conditions, an intended output is not received or measured,c) means for accessing stored data describing the electrical characteristic of selected components of said circuits a fault in any one of which said selected components could be a cause of the said fault symptom,d) means for directly calculating, from the accessed data describing electrical characteristics of said selected components, expected electrical parameter values at predetermined measurement points in a non-defective sub-circuit defined by said selected components and said interconnections therebetween given the said predetermined set of circuit conditions,e) means for selecting measurement points in said sub-circuit at which points said electrical parameter values are to be measured,(f) means for selectively inputting measurement data indicating the electrical parameter values measured at said selected measurement points,g) means for providing a comparison of said input measurement data with said calculated expected electrical parameter values, andh) means for identifying at least one most likely faulty component from the comparison of said input measurement data with said calculated expected electrical parameter values.
3 Assignments
0 Petitions
Accused Products
Abstract
A system for identifying faults in an electrical circuit such as a circuit of a road vehicle. The electrical circuit is intended to provide a plurality of outputs such as lamp illumination in response to predetermined circuit conditions. Data describing individual components of the electrical circuit and the interconnections therebetween is stored. Data identifying a fault symptom is input to the system by a technician to indicate that for one said predetermined set of circuit conditions the intended output is not provided. Stored data is accessed which describes selected components which if faulty could be the cause of the fault symptom. Values of electrical variables to be expected at predetermined measurement points in a sub-circuit defined by the selected components and the connections therebetween are calculated. Measurement points are selected at which points the electrical variables are to be measured and the technician is instructed to selectively input measurement data indicating the electrical variables measured at the selected measurement points. The input measurement data is compared with the calculated electrical variables and faulty components are identified in accordance with that comparison data.
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Citations
11 Claims
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1. A system for identifying faults in an electrical circuit intended to provide a plurality of outputs, each output being in response to at least one predetermined set of circuit conditions, the system comprising
a) means storing data describing individual components of an electrical circuit and interconnections at circuit nodes between said components that together define the topology of the electrical circuit, b) means for inputting data to the system identifying a fault symptom indicating that, for one predetermined set of said circuit conditions, an intended output is not received or measured, c) means for accessing stored data describing the electrical characteristic of selected components of said circuits a fault in any one of which said selected components could be a cause of the said fault symptom, d) means for directly calculating, from the accessed data describing electrical characteristics of said selected components, expected electrical parameter values at predetermined measurement points in a non-defective sub-circuit defined by said selected components and said interconnections therebetween given the said predetermined set of circuit conditions, e) means for selecting measurement points in said sub-circuit at which points said electrical parameter values are to be measured, (f) means for selectively inputting measurement data indicating the electrical parameter values measured at said selected measurement points, g) means for providing a comparison of said input measurement data with said calculated expected electrical parameter values, and h) means for identifying at least one most likely faulty component from the comparison of said input measurement data with said calculated expected electrical parameter values.
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8. A method for identifying a fault in an electrical circuit exhibiting a fault symptom and having electrical components with known expected electrical characteristics connected between circuit nodes in a pre-defined topography, said method comprising:
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maintaining a data base defining a plurality of electrical circuits, including their electrical components and inter-node connections of same; selecting, from the data base, data defining a particular sub-circuit of a circuit to be analyzed, including all interconnected components which are capable of causing said fault symptom; generating, from said data base, a visual display of said particular sub-circuit and of selected test points therein; calculating an expected value of electrical parameters at said selected test points based on the known expected electrical characteristics of components within said sub-circuit; and comparing measured values of electrical parameters at said selected test points with calculated expected values to identify a possibly faulty component within said particular sub-circuit. - View Dependent Claims (9)
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10. Apparatus for identifying a fault in an electrical circuit exhibiting a fault symptom and having electrical components with known expected electrical characteristics connected between circuit nodes in a pre-defined topography, said apparatus comprising:
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means for maintaining a data base defining a plurality of electrical circuits including their electrical components and inter-node connections of same; means for selecting, from the data base, data defining a particular sub-circuit of a circuit to be analyzed, including all interconnected components which are capable of causing said fault symptom; means for generating, from said data base, a visual display of said particular sub-circuit and of selected test points therein; means for calculating an expected value of electrical parameters at said selected test points based on the known expected electrical characteristics of components within said sub-circuit; and means for comparing measured values of electrical parameters at said selected test points with calculated expected values to identify a possibly faulty component within said particular sub-circuit. - View Dependent Claims (11)
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Specification