Particulate detection apparatus

Patent metadata

Field	Value
Publication number	US-11137332-B2
Application number	US-201916505262-A
Country	US
Kind code	B2
Filing date	Jul 8, 2019
Priority date	Jul 9, 2018
Publication date	Oct 5, 2021
Grant date	Oct 5, 2021

Abstract

A particulate detection apparatus for controlling a particulate sensor which detects the amount of particulates discharged from a filter for collecting particulates contained in exhaust gas. The particulate sensor includes a detection section configured to electrify particulates contained in exhaust gas so as to produce electrified particulates. The particulate detection apparatus includes a period judgment section, an output obtainment section and an anomaly judgment section. The period judgment section judges whether or not the present point in time is within a previously set anomaly determination period just after completing a filter regeneration process. The output obtainment section obtains a sensor output representing the result of detection by the particulate sensor in the case where the present point in time is judged to be within the anomaly determination period. The anomaly judgment section judges whether or not the particulate sensor is anomalous based on the sensitivity characteristic of the sensor output.

First claim

What is claimed is:

1. A particulate detection apparatus for controlling a particulate sensor which detects an amount of particulates discharged from a filter attached to an exhaust pipe of an internal combustion engine for collecting particulates contained in exhaust gas discharged from the internal combustion engine,
the particulate sensor including a detection section configured to electrify particulates contained in the exhaust gas flowing into an interior of the detection section so as to produce electrified particulates,
the particulate detection apparatus comprising:
a period judgment section configured to judge whether or not a present point in time is within a previously set anomaly determination period just after completing a filter regeneration process for regenerating the filter by removing the particulates collected by the filter;
an output obtainment section configured to obtain a sensor output representing the result of detection by the particulate sensor in the case where the period judgment section judges that the present point in time is within the anomaly determination period; and
an anomaly judgment section configured to judge whether or not the particulate sensor is anomalous based on a sensitivity characteristic of the sensor output obtained by the output obtainment section.

2. The particulate detection apparatus as claimed in claim 1 , wherein the detection section includes a discharge section configured to generate ions by means of corona discharge and is configured to cause the generated ions to adhere to the particulates contained in the exhaust gas, thereby electrifying the particulates,
wherein the particulate sensor includes a heating section configured to heat the discharge section, and
wherein the particulate detection apparatus comprises:
a heating execution section configured to execute the heating by the heating section in the case where the anomaly judgment section judges that the particulate sensor is anomalous; and
an anomaly conclusive determination section configured to conclusively determine that the particulate sensor is anomalous in the case where a number of times the anomaly judgment section has judged that the particulate sensor is anomalous is greater than a previously set number of times for an anomaly conclusive determination.

3. The particulate detection apparatus as claimed in claim 1 , wherein the anomaly judgment section comprises:
an upstream particulate amount obtainment section configured to obtain upstream particulate amount information representing an upstream particulate amount which is the amount of the particulates contained in the exhaust gas before flowing into the filter;
a first relevant value computation section configured to compute a first downstream particulate relevant value, which relates to the amount of the particulates discharged from the filter within the anomaly determination period, based on the upstream particulate amount represented by the upstream particulate amount information obtained by the upstream particulate amount obtainment section and a previously set collection efficiency just after regeneration which represents the collection efficiency of the filter just after completing the filter regeneration process; and
a second relevant value computation section configured to compute a second downstream particulate relevant value, which relates to the amount of particulates discharged from the filter within the anomaly determination period, based on the sensor output obtained by the output obtainment section,
wherein the anomaly judgment section judges whether or not the particulate sensor is anomalous based on the sensitivity characteristic obtained using the first downstream particulate relevant value computed by the first relevant value computation section and the second downstream particulate relevant value computed by the second relevant value computation section.

4. The particulate detection apparatus as claimed in claim 3 , wherein each of the first downstream particulate relevant value and the second downstream particulate relevant value is the average of the amount of the particulates discharged from the filter within the anomaly determination period.

5. The particulate detection apparatus as claimed in claim 3 , wherein each of the first downstream particulate relevant value and the second downstream particulate relevant value is a cumulative value obtained by cumulating the amount of particulates discharged from the filter within the anomaly determination period.

Assignees

• Ngk Spark Plug Co

Inventors

• Sugiyama Takeshi
• Hibino Yoshinori

Classifications

• B01D46/84

  by heating only · CPC title

• G01N2015/0046

  in gas, e.g. smoke · CPC title

• B01D2279/30

  for treatment of exhaust gases from IC Engines · CPC title

• B01D46/442

  by measuring the concentration of particles · CPC title

• F01N11/00

  Monitoring or diagnostic devices for exhaust-gas treatment apparatus · CPC title