Control apparatus for internal combustion engine

Patent metadata

Field	Value
Publication number	US-10344697-B2
Application number	US-201715632999-A
Country	US
Kind code	B2
Filing date	Jun 26, 2017
Priority date	Jun 28, 2016
Publication date	Jul 9, 2019
Grant date	Jul 9, 2019

Abstract

An internal combustion engine has a humidity sensor that is disposed in an intake passage of the internal combustion engine, a temperature sensor configured to detect an intake air temperature in a position of the humidity sensor, and a controller configured to correct an offset error of the sensor value by adding a correction value to the sensor value. The controller is configured to acquire the intake air temperatures respectively at a plurality of timings in a process of the intake air temperature changing, acquire the sensor values at the respective plurality of timings, calculate values excluding influences of temperature differences of the intake air temperatures from the respective sensor values as humidity index values respectively, and determine a correction value so that a variation degree of the humidity index values becomes small.

First claim

What is claimed is:

1. A control apparatus for an internal combustion engine comprising:
a humidity sensor that is disposed in an intake passage of the internal combustion engine, and is configured to detect a sensor value corresponding to relative humidity of intake air in the intake passage;
a temperature sensor configured to detect an intake air temperature in a position of the humidity sensor; and
a controller configured to correct an offset error of the sensor value by performing correction by adding a correction value to the sensor value,
the controller being configured to:
acquire the intake air temperatures at a plurality of timings in a process of the intake air temperature changing;
acquire the sensor values at the respective plurality of timings;
calculate respective humidity index values that are not dependent on influences of temperature differences of the intake air temperatures using values obtained by adding respective relative humidity change amounts to the respective sensor values;
determine the relative humidity change amount that causes a variation degree of the humidity index values to become small; and
set the determined relative humidity change amount as the correction value,
wherein the control apparatus controls the internal combustion engine using sensor values that are corrected by adding the correction value.

2. The control apparatus for the internal combustion engine according to claim 1 ,
wherein the controller is configured to calculate absolute humidity values as the respective humidity index values which are calculated by using the values obtained by adding the respective relative humidity change amounts to the respective sensor values and the intake air temperature corresponding to the respective sensor values.

3. The control apparatus for the internal combustion engine according to claim 1 ,
wherein the controller is configured to calculate relative humidity values at a time of the intake air temperature being a predetermined reference intake air temperature as the respective humidity index values by using the values obtained by adding the respective relative humidity change amounts to the respective sensor values.

4. The control apparatus for the internal combustion engine according to claim 1 ,
wherein the controller is configured to determine the correction value so that the variance degree of the humidity index values becomes minimum.

5. The control apparatus for the internal combustion engine according to claim 1 ,
wherein the controller is configured to:
during the acquiring of the intake air temperatures at a plurality of timings and the acquiring of the sensor values at the respective plurality of timings, acquire a first sensor value that is the sensor value at a time of the intake air temperature being a first intake air temperature, and a second sensor value that is the sensor value at a time of the intake air temperature changing from the first intake air temperature and reaching a second intake air temperature,
during the calculating of the respective humidity index values, calculate values that are not dependent on an influence of a temperature difference of the first intake air temperature and the second intake air temperature using values obtained by adding respective relative humidity change amounts to the first sensor value and the second sensor value, as first humidity index values and second humidity index values respectively, and
during the determining of the relative humidity change amount and the setting of the determined relative humidity change amount, determine the relative humidity change amount that causes a difference value of a corresponding one of the first humidity index values and the second humidity index values to be close to zero and set the determined relative humidity change amount as the correction value.

6. The control apparatus for the internal combustion engine according to claim 1 ,
wherein the controller is configured to restrict acquisition of the sensor value, until an integrated value of a volume of intake air that is taken into the intake passage after start of the internal combustion engine exceeds a capacity from an inlet to the humidity sensor in the intake passage, in a warm-up period of the internal combustion engine.

7. The control apparatus for the internal combustion engine according to claim 1 ,
wherein the controller is configured to restrict acquisition of the sensor value, when intake air containing a fuel component flows in the position of the humidity sensor in the intake passage of the internal combustion engine.

8. A control apparatus for an internal combustion engine comprising:
a humidity sensor that is disposed in an intake passage of the internal combustion engine, and is configured to detect a sensor value corresponding to relative humidity of intake air in the intake passage;
a temperature sensor configured to detect an intake air temperature in a position of the humidity sensor; and
a controller configured to correct an offset error of the sensor value by performing correction by adding a correction value to the sensor value,
the controller being configured to
acquire the intake air temperatures at a plurality of timings in a process of the intake air temperature changing;
acquire the sensor values at the respective plurality of timings;
calculate respective relative humidity differences between relative humidity values calculated using respective reference absolute humidity values and relative humidity values calculated using the sensor values as respective humidity index values, and
calculate the reference absolute humidity value at which a variation degree of the relative humidity differences becomes minimum, and
set an average value of the relative humidity differences at the calculated reference absolute humidity as the correction value,
wherein the control apparatus controls the internal combustion engine using sensor values that are corrected by adding the correction value.

9. A control apparatus for an internal combustion engine comprising:
a humidity sensor that is disposed in an intake passage of the internal combustion engine, and is configured to detect a sensor value corresponding to relative humidity of intake air in the intake passage;
a temperature sensor configured to detect an intake air temperature in a position of the humidity sensor; and
a controller configured to correct an offset error of the sensor value by performing correction by adding a correction value to the sensor value,
the controller being configured to:
acquire the intake air temperatures at a plurality of timings in a process of the intake air temperature changing;
acquire the sensor values at the respective plurality of timings;
calculate respective absolute humidities by using the respective sensor values and the intake air temperatures corresponding to the respective sensor values;
calculate respective humidity index values obtained by adding absolute humidity change amounts calculated from respective relative humidity change amounts to the respective absolute humidities;
determine the absolute humidity change amounts that cause a variation degree of the humidity index values to become small; and
set the relative humidity change amount used to calculate the determined absolute humidity change amounts as the correction value,
wherein the control apparatus controls the internal combustion engine using the sensor values that are corrected by adding the correction value.

Assignees

• Toyota Motor Co Ltd

Inventors

• Ito Hironori

Classifications

• F02D2200/0414

  Air temperature · CPC title

• F02D41/2474 Primary

  Characteristics of sensors · CPC title

• F02D41/0065

  Specific aspects of external EGR control (constructional details of EGR system F02M26/00) · CPC title

• G01N33/007

  Arrangements to check the analyser (calibrating gas analysers G01N33/0006) · CPC title

• F02D2200/0418

  Air humidity · CPC title