Pressure sensor diagnosis via a computer
AssigneeFord Global Technologies, LLC
InventorMichiel J. van Nieuwstadt
Life of this patent
Estimating the term…
Abstract
A method is described for controlling regeneration of a particulate filter based on at least a sensor, such as a differential pressure sensor. Degradation of the sensor is then detected in a variety of ways. One approach takes advantage of the slowly varying flow resistance of the filter compared with the more rapid variations in flow caused by changing engine conditions. Default operation is then taken when a degraded sensor is detected.
Claims29
A system for a vehicle having an engine with an exhaust system, the system comprising:
- a pressure sensor coupled in the engine exhaust;
- a particulate filter coupled in the engine exhaust;
- and
- a computer storage medium having a computer program encoded therein for determining degradation of said exhaust pressure sensor, comprising:
- code for determining at least a parameter based on at least two flow conditions;
- code for measuring a signal from the exhaust pressure sensor;
- and
- code for determining degradation of the exhaust pressure sensor based at least on said parameter and said signal.
A method for monitoring a pressure sensor, the sensor responding to both a first and second parameter, the method comprising:
- measuring a signal from the pressure sensor at least during a condition where variation of the first parameter is greater than a first amount and variation of the second parameter is less than a second amount;
- and
- determining degradation of the sensor based on said signal and a reference.
A method for monitoring a pressure sensor in an engine exhaust, the method comprising:
- measuring a signal from the pressure sensor during at least a first and second flow condition;
- determining an expected response of the sensor during said flow conditions;
- and
- determining degradation of the sensor when said signal differs by an amount from said expected response.
A system for a vehicle having an engine with an exhaust system, the system comprising:
- a pressure sensor coupled in the engine exhaust;
- a particulate filter coupled in the engine exhaust;
- and
- a computer storage medium having a computer program encoded therein for determining degradation of said exhaust pressure sensor, comprising:
- code for determining an expected sensor response;
- code for measuring a signal response from the exhaust pressure sensor during at least a selected engine operating condition;
- and
- code for determining degradation of the exhaust pressure sensor based at least on said expected sensor response and said signal response.
A system for a vehicle having an engine with an exhaust system, the system comprising:
- a particulate filter coupled in the engine exhaust;
- a sensor coupled in the engine exhaust;
- and
- a computer storage medium having a computer program encoded therein, comprising:
- code for regenerating said particulate filter based on said sensor;
- and
- code for determining degradation of said sensor based on an operating parameter.
A system for a vehicle having an engine with an exhaust system, the system comprising:
- a sensor coupled in the engine exhaust so that the sensor is exposed to the exhaust;
- a particulate filter coupled in the engine exhaust with the sensor;
- and
- a computer storage medium having a computer program encoded therein for determining degradation of said sensor, comprising:
- code for determining at least an operating parameter of the sensor based on at least two flow conditions of the exhaust;
- code for measuring a signal from the sensor over time;
- and
- code for determining degradation of the sensor over time based at least on said parameter and said signal.
Dependencies are inferred from the claim text.