Process for the diagnosis of an ignition device of an internal combustion engine
AssigneeSiemens Automotive Corporation
InventorsGilles Hannoyer, Philippe Blanchard, Catherine Meyer, Yves Geoffroy
Life of this patent
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Abstract
The diagnosis of an open-circuit fault or of a short-circuit in an ignition system is effected by performing asynchronous periodic extraction of samples of current in a switch. A check is made to ensure the satisfaction of certain temporal conditions in respect to a moment of extraction of the samples and comparing the samples, on the basis of that the temporal conditions are satisfied, with predetermined fault threshold values.
Claims10
A process for diagnosing an ignition device of an internal combustion engine, which comprises:
- providing an ignition device including at least one ignition coil, providing a switch connected to the at least one ignition coil, providing a control computer emitting at least one control signal for controlling the switch, and providing a current measuring means for measuring a current flowing through the switch;
- performing a sampling step defined by periodically extracting samples of a value of the current flowing through the switch with the current measuring means;
- performing a determining step defined by determining a moment of extraction and a conducting state of a circuit formed of the at least one coil and the switch at the moment of extraction for each of the samples;
- performing a checking step defined by checking if the moment of extraction for each of the samples satisfies at least one temporal condition with respect to the at least one control signal emitted by the control computer;
- performing a comparing step defined by comparing each of the samples with a predetermined threshold value if the at least one temporal condition was satisfied during the checking step;
- and
- performing a deducing step defined by deducing a presence and nature of an operating fault of the circuit from results of the comparing step.
In an ignition device having a plurality of circuits each formed of a coil and a switch, a diagnosis apparatus comprising:
- current measuring means for measuring a current common to a plurality of circuits;
- means for determining a moment of events including a moment of extraction of current measuring samples, and a moment of turning on and off a respective switch of the plurality of circuits;
- storage means for recording at least one collection of values including a current sample, a moment of extraction of the current sample, a reference to a conduction state of each of the plurality of circuits, a set of pre-established threshold values and time lag values, and an instruction set forming part of a piece of software;
- and
- calculation and comparison means for executing checking and comparison operations defined according to a process by running and executing said instruction set stored in said storage means.
In an ignition device having a plurality of circuits each formed of a coil and a switch, an electronic ignition computer comprising:
- current measuring means for measuring a current common to a plurality of circuits;
- means for determining a moment of events including a moment of extraction of current measuring samples, and a moment of turning on and off a respective switch of the plurality of circuits;
- storage means for recording at least one collection of values including a current sample, a moment of extraction of the current sample, a reference to a conduction state of each of the plurality of circuits, a set of pre-established threshold values and time lag values, and an instruction set forming part of a piece of software;
- and
- calculation and comparison means for executing checking and comparison operations defined according to a process by running and executing said instruction set stored in said storage means.
Dependencies are inferred from the claim text.