Dew point activation method for exhuast gas sensors
AssigneeContinental Automotive Systems, Inc.
InventorJohn Patrick Schuster
Life of this patent
Estimating the term…
Abstract
An emission control system, such as an emission control system for a diesel engine, which includes both a NOx sensor and an electrostatic Particulate Matter (ePM) sensor, and uses the signal from the ePM sensor to determine when it is safe to activate and heat up the NOx sensor after engine ignition. This is performed as soon as moisture clears the exhaust, without having to wait any additional time as a safety factor to maximize the reliability of the NOx sensor against damage from water thermal shock. It also allows for a higher degree of application flexibility for a specific engine and aftertreatment combination to be used in a variety of vehicle applications, environmental conditions, and vehicle operating profiles.
Claims16
An exhaust system for a vehicle, comprising:
- a first sensor operable for detecting current created by the flow of particles in exhaust gas;
- and
- a nitrogen oxide sensor;
- wherein the amount of a substance in the exhaust system changes the current detected by the first sensor, such that when the current detected by the first sensor is above a predetermined value, the substance is present in the exhaust system, and when the substance has been removed from the exhaust system, the current detected by the first sensor is at or below the predetermined value, and the nitrogen oxide sensor is activated when the current generated by the first sensor is at or below the predetermined value.
A method for determining when to activate a sensor, comprising the steps of:
- providing an exhaust system for a vehicle;
- providing a first sensor being part of the exhaust system;
- and
- providing a NOx sensor being part of the exhaust system;
- measuring a current generated by the first sensor to detect the presence of a substance;
- detecting the presence of a substance in the exhaust system if the current generated by the first sensor is above a predetermined value;
- activating the NOx sensor once the current measured by the first sensor is at or below the predetermined value.
Dependencies are inferred from the claim text.