Diagnostic system and method for nitrogen oxide sensor

摘要

A system including a nitrogen oxide sensor and a controller is provided. The nitrogen oxide sensor is configured to generate a first signal indicative of nitrogen oxides content in an exhaust gas. The controller is communicably coupled to the nitrogen oxide sensor. The controller configured to receive the first signal indicative of nitrogen oxides content in the exhaust gas. The controller is also configured to receive a second signal corresponding to an operational parameter of a power source. Further, the controller is configured to compare a derivative of the first signal with a derivative of the second signal. The controller is configured to trigger an error counter when an absolute value of the compared derivative crosses a predetermined threshold. Thereafter, the controller is configured to determine a condition of the nitrogen oxide sensor based on a count of the error counter in a predetermined period of time.

主权项

1. A system comprising:
a nitrogen oxide sensor configured to generate a first signal indicative of, a content of nitrogen oxides in an exhaust gas over time; a fuel flow sensor configured to generate a second signal indicative of a fuel quantity introduced to an engine over time; and a controller communicably coupled to the nitrogen oxide sensor and the fuel flow sensor, the controller configured to:
receive, from the nitrogen oxide sensor, the first signal indicative of a content of nitrogen oxides in the exhaust gas over time;receive the second signal indicative of a fuel quantity introduced to an internal combustion engine over time;subtract a first order time derivative of the first signal from a first order time derivative of the second signal to arrive at a calculated difference;trigger an error counter when an absolute value of the calculated difference is greater than a predetermined threshold; anddetermine a condition of the nitrogen oxide sensor based on a count of the error counter in a predetermined period of time; andcommunicate the determined condition of the nitrogen oxide sensor to an operator.