System and method for detecting faulty fuel tank level sensor
First Claim
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1. A fluid level sensor monitoring method, comprising:
- monitoring an actual sensor output from the fluid level sensor;
calculating an estimated sensor output based on a fluid consumption variable value by calculating a difference between a reference sensor value and the fluid consumption variable to obtain the estimated sensor output;
setting the reference sensor value equal to the actual sensor output to obtain a new reference sensor value if the reference sensor value varies by a predetermined threshold; and
indicating a sensor malfunction if a difference between the actual sensor output and the estimated sensor output is outside a first threshold.
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Abstract
A system and method for detecting a stuck or malfunctioning fuel tank level sensor calculates an estimated fuel tank level sensor value and compares the estimated sensor value with the actual sensor value. Upper and lower threshold values may also be determined along with the estimated value. If the actual sensor value falls outside the threshold values, the sensor is considered faulty and an error signal is set in the system. The system also compares the actual sensor value with a reference sensor value to detect whether the fault is due to a stuck sensor or due to a different type of sensor malfunction.
22 Citations
19 Claims
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1. A fluid level sensor monitoring method, comprising:
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monitoring an actual sensor output from the fluid level sensor;
calculating an estimated sensor output based on a fluid consumption variable value by calculating a difference between a reference sensor value and the fluid consumption variable to obtain the estimated sensor output;
setting the reference sensor value equal to the actual sensor output to obtain a new reference sensor value if the reference sensor value varies by a predetermined threshold; and
indicating a sensor malfunction if a difference between the actual sensor output and the estimated sensor output is outside a first threshold. - View Dependent Claims (2, 3)
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4. A fluid level sensor monitoring method, comprising:
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monitoring an actual sensor output from the fluid level sensor;
calculating an estimated sensor output based on a fluid consumption variable value;
indicating a sensor malfunction if a difference between the actual sensor output and the estimated sensor output is outside a first threshold;
comparing the actual sensor output with a reference sensor value; and
distinguishing between a first sensor malfunction and a second sensor malfunction based on the comparing step. - View Dependent Claims (5, 6)
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7. A fluid level sensor monitoring method, comprising:
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monitoring an actual sensor output from the fluid level sensor;
calculating an estimated sensor output based on a fluid consumption variable value;
indicating a sensor malfunction if a difference between the actual sensor output and the estimated sensor output is outside a first threshold, wherein the indicating step comprises;
incrementing a counter when the difference between the actual sensor output and the estimated sensor output is outside a first threshold; and
indicating the sensor malfunction when the counter reaches a counter threshold.
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8. A method of monitoring a fuel tank level sensor, comprising:
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monitoring an actual sensor output from the fuel tank level sensor;
calculating a difference between to obtain a reference sensor value and a fuel consumption variable to obtain an estimated sensor output;
indicating a sensor malfunction if a difference between the actual sensor output and the estimated sensor output is outside a first threshold; and
indicating a stuck signal error, corresponding to a stuck condition, if a difference between the actual sensor value and the reference sensor value is inside a second threshold; and
indicating an implausible signal error, corresponding to a defective condition, if the difference between the actual sensor value and the reference sensor value is outside the second threshold. - View Dependent Claims (9, 10, 11, 12)
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13. A fluid level monitoring system, comprising:
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a fluid level sensor; and
a processor coupled to the fluid level sensor, wherein the processor executes an algorithm comprising the steps of;
monitoring an actual sensor output from the fluid level sensor;
calculating a difference between a reference sensor value and a fluid consumption variable to obtain an estimated sensor output;
setting the reference sensor value is equal to the actual sensor output to obtain a new reference sensor value if the reference sensor value vanes by a predetermined threshold, and indicating a sensor malfunction if a difference between the actual sensor output and the estimated sensor output is outside a first threshold. - View Dependent Claims (14, 15)
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16. A fluid level monitoring system, comprising:
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a fluid level sensor; and
a processor coupled to the fluid level sensor, wherein the processor executes an algorithm comprising the steps of;
monitoring an actual sensor output from the fluid level sensor;
calculating a difference between a reference sensor value and a fluid consumption variable to obtain an estimated sensor output; and
indicating a sensor malfunction if a difference between the actual sensor output and the estimated sensor output is outside a first threshold;
comparing the actual sensor output with a reference sensor value; and
distinguishing between a first sensor malfunction and a second sensor malfunction based on the comparison. - View Dependent Claims (17, 18)
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19. A fluid level monitoring system, comprising:
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a fluid level sensor; and
a processor coupled to the fluid level sensor, wherein the processor executes an algorithm comprising the steps of;
monitoring an actual sensor output from the fluid level sensor, calculating a difference between a reference sensor value and a fluid consumption variable to obtain an estimated sensor output, indicating a sensor malfunction if a difference between the actual sensor output and the estimated sensor output is outside a first threshold by incrementing a counter when the difference between the actual sensor output and the estimated sensor output is outside a first threshold and indicating the sensor malfunction when the counter reaches a counter threshold.
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Specification