Fault detector and method of detecting faults
First Claim
1. A fault detector for detecting valve movement of a valve in a fuel injector of an engine system, the valve comprising an electromagnetic actuator arranged to move the valve between first and second valve positions during a valve cycle, the engine system comprising a sensor for sensing a current through the actuator, the detector comprising:
- a controller arranged to control the sensor;
inputs for receiving from the sensor data related to the current through the actuator;
a processor arranged to analyze the received data for current discontinuities; and
outputs for outputting a valve movement signal in dependence upon the current discontinuities determined by the processor;
wherein the controller is arranged to enable the sensor during a finite sampling window;
to move the sampling window from a first window position for a first injection event to a progressively later window position for one or more subsequent injection events;
to determine a new sampling window position on the basis of a valve movement signal output for at least two of the preceding window positions; and
to feedback the new sampling window position for a subsequent injection event.
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Accused Products
Abstract
A fault detector for detecting valve movement of a valve in a fuel injector of an engine system, the valve comprising an electromagnetic actuator arranged to move the valve between first and second valve positions during a valve cycle, the engine system comprising a sensor for sensing a current through the actuator. The detector comprises a controller arranged to control the sensor; inputs for receiving from the sensor data related to the current through the actuator; a processor arranged to analyze the received data for current discontinuities; and outputs for outputting a valve movement signal in dependence upon the current discontinuities determined by the processor. The controller is arranged to enable the sensing means during a finite sampling window and to: (i) move the sampling window from a first window position for a first injection event to a progressively later window position for one or more subsequent injection events; (ii) to determine a new sampling window position on the basis of a valve movement signal output for at least two of the preceding window positions; and (iii) to feedback the new sampling window position for a subsequent injection event.
34 Citations
24 Claims
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1. A fault detector for detecting valve movement of a valve in a fuel injector of an engine system, the valve comprising an electromagnetic actuator arranged to move the valve between first and second valve positions during a valve cycle, the engine system comprising a sensor for sensing a current through the actuator, the detector comprising:
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a controller arranged to control the sensor; inputs for receiving from the sensor data related to the current through the actuator; a processor arranged to analyze the received data for current discontinuities; and outputs for outputting a valve movement signal in dependence upon the current discontinuities determined by the processor; wherein the controller is arranged to enable the sensor during a finite sampling window;
to move the sampling window from a first window position for a first injection event to a progressively later window position for one or more subsequent injection events;
to determine a new sampling window position on the basis of a valve movement signal output for at least two of the preceding window positions; and
to feedback the new sampling window position for a subsequent injection event. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19)
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20. A method of detecting valve movement of a valve in a fuel injector of an engine system, the valve comprising an electromagnetic actuator that is arranged to move the valve between first and second positions during a valve cycle, the method comprising:
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sampling the current through the actuator during a finite sampling window, analyzing the sampled current for current discontinuities, and determining valve movements in dependence upon the current discontinuities, wherein the sampling window is moved from a first window position for a first injection event to a progressively later window position for one or more subsequent injection events, and in that the method further comprises calculating a new sampling window position on the basis of a fault detect signal output for at least two of the preceding window positions; and
feeding back the new sampling window position for a subsequent injection event. - View Dependent Claims (23)
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21. A fault detector for detecting valve movement of a valve in a fuel injector of an engine system, the valve comprising an electromagnetic actuator that is arranged to move the valve between first and second positions during a valve cycle, the detector comprising:
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inputs for receiving data related to the current through the actuator; a processor arranged to analyze the received data for current discontinuities; and outputs for outputting a valve movement signal in dependence upon the current discontinuities determined by the processor; wherein the processor is arranged to analyze the received data by determining the second derivative with respect to time of the current through the actuator and is further arranged to determine the second derivative based on a differential process, for which input data points are non-consecutive.
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22. A method of detecting valve movement of a valve in a fuel injector of an engine system, the valve comprising an electromagnetic actuator that is arranged to move the valve between first and second positions during a valve cycle, the method comprising:
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sampling the current through the actuator in order to determine current data; analyzing the sampled current data for current discontinuities; and outputting a valve movement signal in dependence upon the current discontinuities; wherein the current data is analyzed by determining the second derivative with respect to time of the current through the actuator and wherein the second derivative is based on a differential process, for which input data points are non-consecutive.
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24. An engine control unit for a vehicle comprising a detector for detecting valve movement of a valve in a fuel injector of an engine system, the valve comprising an electromagnetic actuator arranged to move the valve between first and second valve positions during a valve cycle, the engine system comprising a sensor for sensing a current through the actuator, the detector comprising:
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a controller arranged to control the sensor; inputs for receiving from the sensor data related to the current through the actuator; a processor arranged to analyze the received data for current discontinuities; and outputs for outputting a valve movement signal in dependence upon the current discontinuities determined by the processor; wherein the controller is arranged to enable the sensor during a finite sampling window;
to move the sampling window from a first window position for a first injection event to a progressively later window position for one or more subsequent injection events;
to determine a new sampling window position on the basis of a valve movement signal output for at least two of the preceding window positions; and
to feedback the new sampling window position for a subsequent injection event.
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Specification