Method and system for improving sensor accuracy
AssigneeCummins Inc.
InventorsEric B. Andrews, Matthew L. Schneider
Life of this patent
Estimating the term…
Abstract
A method and system for improving sensor accuracy of diesel emissions is disclosed. The method and system change the sensor reading as a function of sensor age to provide a more accurate measure of the diesel emissions. By estimating the degree of sensor error and then providing a gain correction factor as a function of sensor age, a more accurate measure of the diesel emissions is provided.
Claims29
A method for improving sensor accuracy when measuring emissions from a vehicle comprising:
- operating a sensor to measure emissions from a vehicle;
- storing an aggregate time indicating the total service age of the sensor;
- and
- changing an output of the sensor indicating measured emissions based upon the aggregate time;
- wherein the changing utilizes a correction factor accounting for a leveling off of sensor sensitivity loss as a function of accumulated emissions concentration and total exhaust mass flow over the aggregate time.
A method for improving sensor accuracy when measuring emissions from a vehicle comprising:
- changing at least one sensor reading as a function of sensor age to provide a more accurate measure of the emissions wherein the changing is implemented in accordance with the following equation:
- NOxactual═NOxsensor×G, where NOxactual comprises the actual emissions, NOxsensor comprises the emissions as measured by the sensor and G comprises a gain correction factor wherein the gain correction factor is determined by estimating the amount of accumulated NOx concentration over a predetermined period of sensor operation.
An engine system comprising:
- an engine;
- an aftertreatment unit coupled to the engine for treating emissions;
- a sensor system, wherein the sensor system includes at least one sensor;
- and
- an electronic control module in communication with the sensor system, wherein the module includes instructions executable by the module for changing at least one sensor emissions reading utilizing a correction factor accounting for a change in the rate of sensor sensitivity loss based upon at least accumulated emissions concentration and total exhaust mass flow over time.
An engine system comprising:
- an engine;
- an aftertreatment unit coupled to the engine for sensing emissions;
- a sensor system, wherein the sensor system includes at least one sensor;
- and
- an electronic control module in communication with the sensor system, wherein the module includes a mechanism for changing the at least one sensor output as a function of the age of the at least one sensor, wherein the changing is implemented in accordance with the following equation:
- NOxactual═NOxsensor×G, where NOxactual comprises the actual emissions, NOxsensor comprises the emissions as measured by the sensor and G comprises a gain correction factor, wherein the gain correction factor is determined by estimating the amount of accumulated NOx concentration over a predetermined time period of sensor operation.
A computer readable medium containing non-transitory program instructions for improving sensor accuracy when measuring emissions from a vehicle comprising:
- instructions for tracking the total time that the sensor has been in operation;
- and instructions for changing a sensor output indicating measured emissions including accounting for a decrease in the rate of sensor sensitivity loss as a function of the time that the sensor has been in service.
A computer readable medium containing non-transitory program instructions for improving sensor accuracy when measuring emissions from a vehicle, the instructions comprising:
- changing at least one sensor reading as a function of sensor age to provide a more accurate measure of the emissions, wherein the changing is implemented in accordance with the following equation:
- NOxactual═NOxsensor×G, where NOxactual comprises the actual emissions, NOxsensor comprises the emissions as measured by the sensor and G comprises a gain correction factor, wherein the gain correction factor is determined by estimating the amount of accumulated NOx concentration over a predetermined time period of sensor operation.
Dependencies are inferred from the claim text.