System for diagnosing reagent solution quality
First Claim
1. A system for diagnosing the quality of a reagent solution, comprising:
- a reagent solution source configured to supply the reagent solution to an emissions catalyst of an internal combustion engine, means for determining a quality value corresponding to the quality of the reagent solution,a long run averaging filter configured to receive the quality value and produce a long run average of the quality value,a short run averaging filter configured to receive the quality value and produce a short run average of the quality value,a comparator configured to compare a difference between the long run average of the quality value and the short run average of the quality value to a first threshold and produce a fault value if the difference crosses the first threshold,a temperature sensor configured to produce a temperature signal indicative of a temperature of the reagent solution, anda threshold determining circuit configured to produce the first threshold as a function of the temperature signal.
3 Assignments
0 Petitions
Accused Products
Abstract
A system for diagnosing the quality of a reagent solution may comprise a reagent solution source for supplying the reagent solution to an emissions catalyst of an internal combustion engine. Means may be provided for determining a quality value corresponding to the quality of the reagent solution. A first filter may receive the quality value and produce a first filtered quality value, and a first comparator may compare the filtered quality value to a threshold and produce a fault value if the first filtered quality value crosses the threshold. Alternatively or additionally, a second filter may receive the quality value and produce a second filtered quality value. A second comparator may compare a difference between the first and second filtered quality values to another threshold and produce another fault value if the difference crosses that threshold.
61 Citations
18 Claims
-
1. A system for diagnosing the quality of a reagent solution, comprising:
-
a reagent solution source configured to supply the reagent solution to an emissions catalyst of an internal combustion engine, means for determining a quality value corresponding to the quality of the reagent solution, a long run averaging filter configured to receive the quality value and produce a long run average of the quality value, a short run averaging filter configured to receive the quality value and produce a short run average of the quality value, a comparator configured to compare a difference between the long run average of the quality value and the short run average of the quality value to a first threshold and produce a fault value if the difference crosses the first threshold, a temperature sensor configured to produce a temperature signal indicative of a temperature of the reagent solution, and a threshold determining circuit configured to produce the first threshold as a function of the temperature signal. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18)
-
Specification