Abnormality detection device for air-fuel ratio sensor, abnormality detection system for air-fuel ratio sensor, data analysis device, and control device for internal combustion engine

Patent metadata

Field	Value
Publication number	US-10844803-B2
Application number	US-202016819363-A
Country	US
Kind code	B2
Filing date	Mar 16, 2020
Priority date	Mar 22, 2019
Publication date	Nov 24, 2020
Grant date	Nov 24, 2020

Abstract

An abnormality detection device for an air-fuel ratio sensor is provided. An air-fuel ratio sensor is provided in an exhaust passage. A storage device stores mapping data specifying a mapping. The mapping outputs an abnormality determination variable using first time series data and second time series data as an input. The first time series data is time series data of an excess amount variable in a first predetermined period. The excess amount variable is a variable corresponding to an excess amount of fuel actually discharged to the exhaust passage in relation to an amount of fuel reacting without excess or deficiency with oxygen contained in a fluid discharged to the exhaust passage. The second time series data is time series data of an air-fuel ratio detection variable in a second predetermined period.

First claim

What is claimed is:

1. An abnormality detection device for an air-fuel ratio sensor that is provided in an exhaust passage of an internal combustion engine, the abnormality detection device, comprising:
a storage device; and
an execution device, wherein
the storage device stores mapping data specifying a mapping,
the mapping outputs an abnormality determination variable using first time series data and second time series data as an input,
the first time series data is time series data of an excess amount variable in a first predetermined period,
the excess amount variable is a variable corresponding to an excess amount of fuel actually discharged to the exhaust passage in relation to an amount of fuel reacting without excess or deficiency with oxygen contained in a fluid discharged to the exhaust passage,
the second time series data is time series data of an air-fuel ratio detection variable in a second predetermined period,
the air-fuel ratio detection variable is a variable related to a detection value of the air-fuel ratio sensor,
the abnormality determination variable is a variable related to presence and absence of an abnormality that decreases responsiveness of the air-fuel ratio sensor,
the execution device is configured to execute an acquisition process, a calculation process, and a handling process,
in the acquisition process, the execution device acquires the first time series data and the second time series data,
in the calculation process, the execution device inputs the first time series data and the second time series data, which are acquired by the acquisition process, to the mapping to calculate a value of the abnormality determination variable, and
in the handling process, when the calculation result of the calculation process indicates the abnormality, the execution device operates predetermined hardware to handle the abnormality.

2. The abnormality detection device according to claim 1 , wherein
the air-fuel ratio detection variable includes a temporally-varying variable, and
the temporally-varying variable is a variable related to temporal variation of the detection value in a sampling period for a value of each air-fuel ratio detection variable configuring the second time series data.

3. The abnormality detection device according to claim 1 , wherein
the air-fuel ratio detection variable includes a difference variable, and
the difference variable is a variable related to a difference between a local maximum of the detection value and a local minimum of the detection value in a sampling period for a value of each air-fuel ratio detection variable configuring the second time series data.

4. The abnormality detection device according to claim 1 , wherein the excess amount variable is determined based on an actual amount of fuel injected by a fuel injection valve of the internal combustion engine.

5. The abnormality detection device according to claim 1 , wherein
the internal combustion engine includes:
a canister configured to collect fuel vapor from a fuel tank, the fuel tank storing fuel that is to be injected from a fuel injection valve;
a purge passage configured to connect the canister to an intake passage of the internal combustion engine; and
an adjustment device configured to adjust a flow rate of the fuel vapor, the fuel vapor flowing into the intake passage from the canister through the purge passage, and

the excess amount variable includes a purge variable that is a variable related to the flow rate of the fuel vapor.

6. The abnormality detection device according to claim 1 , wherein
the internal combustion engine includes a forced induction device upstream of the air-fuel ratio sensor in the exhaust passage,
the exhaust passage includes a bypass passage that bypasses the forced induction device,
the bypass passage has a flow path cross-sectional area that is adjusted by a wastegate valve,
the input to the mapping includes a flow path variable that is a variable related to the flow path cross-sectional area of the bypass passage,
the acquisition process includes a process that acquires the flow path variable, and
the calculation process includes a process that calculates the value of the abnormality determination variable based on an output of the mapping in which the flow path variable is further included in the input to the mapping.

7. The abnormality detection device according to claim 1 , wherein
the internal combustion engine includes:
an exhaust gas recirculation (EGR) passage configured to connect the exhaust passage to an intake passage; and
an EGR valve configured to adjust a flow rate of a fluid flowing from the exhaust passage into the intake passage through the EGR passage,

the input to the mapping includes an EGR variable that is a variable related to the flow rate of the fluid flowing into the intake passage from the exhaust passage,
the acquisition process includes a process that acquires the EGR variable, and
the calculation process includes a process that calculates the value of the abnormality determination variable based on an output of the mapping in which the EGR variable is further included in the input to the mapping.

8. The abnormality detection device according to claim 1 , wherein
the internal combustion engine includes a valve characteristic variable device configured to change a valve characteristic of an intake valve,
the input to the mapping includes a valve characteristic variable that is a variable related to the valve characteristic,
the acquisition process includes a process that acquires the valve characteristic variable, and
the calculation process includes a process that calculates the value of the abnormality determination variable based on an output of the mapping in which the valve characteristic variable is further included in the input to the mapping.

9. The abnormality detection device according to claim 1 , wherein the calculation process includes a process that calculates the value of the abnormality determination variable based on the first time series data and the second time series data acquired by the acquisition process on condition that a flow rate of the fluid discharged to the exhaust passage is within a predetermined range.

10. The abnormality detection device according to claim 1 , wherein
the exhaust passage is provided with a catalyst,
the air-fuel ratio sensor is an upstream air-fuel ratio sensor disposed at an upstream side of the catalyst in the exhaust passage,
a downstream air-fuel ratio sensor is provided at a downstream side of the catalyst in the exhaust passage,
the execution device executes a main feedback process and a sub-feedback process,
the main feedback process feedback-controls the detection value of the upstream air-fuel ratio sensor to a target value,
when the detection value of the downstream air-fuel ratio sensor is richer than a stoichiometric air-fuel ratio by a predetermined amount or more, the sub-feedback process causes the target value to be leaner than the stoichiometric air-fuel ratio,
when the detection value of the downstream air-fuel ratio sensor is leaner than the stoichiometric air-fuel ratio by a predetermined amount or more, the sub-feedback process causes the target value to be richer than the stoichiometric air-fuel ratio, and
in synchronization with a point in time when the target value is switched from rich to lean and a point in time when the target value is switched from lean to rich, the acquisition process sets the first predetermined period and sets the second predetermined period after the first predetermined period.

11. The abnormality detection device according to claim 1 , wherein
the storage de

Assignees

• Toyota Motor Co Ltd

Inventors

• Muto Harufumi
• Katayama Akihiro
• Mori Kohei
• Hashimoto Yosuke

Classifications

• Y02T10/40

  Engine management systems · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• F02D2041/1409

  using at least a proportional, integral or derivative controller · CPC title

• F02D2041/001

  for engines with variable valve actuation · CPC title

• F02D41/30

  Controlling fuel injection {(F02D41/182, F02D41/24 take precedence)} · CPC title