Engine controller and engine control method

Patent metadata

Field	Value
Publication number	US-10947922-B2
Application number	US-201916454192-A
Country	US
Kind code	B2
Filing date	Jun 27, 2019
Priority date	Jul 13, 2018
Publication date	Mar 16, 2021
Grant date	Mar 16, 2021

Abstract

A first intake air amount an engine is calculated based on a detected value of an intake air flow rate of an air flowmeter. A second intake air amount is calculated based on any one of a detected value of an intake pipe pressure and a throttle opening degree instead of the detected value of the intake air flow rate. When it is determined that the intake pulsation is not large, a difference amount of the second intake air amount from the first intake air amount is calculated. A corrected second intake air amount, which is a sum of the second intake air amount and the difference amount, is set as an intake air amount calculated value when it is determined that the intake pulsation is large.

First claim

What is claimed is:

1. An engine controller configured to execute:
a first intake air amount calculation process for calculating a first intake air amount, which serves as a calculated value of an intake air amount of an engine, based on a detected value of an intake air flow rate of an air flowmeter;
a second intake air amount calculation process for calculating a second intake air amount, which serves as a calculated value of an intake air amount of the engine, based on any one of a detected value of an intake pipe pressure and a throttle opening degree instead of the detected value of the intake air flow rate;
a determination process for determining whether intake pulsation in an intake passage of the engine is large by determining whether the pulsation is greater than or equal to a preset determination value;
a difference amount calculation process for, when determining in the determination process that the intake pulsation is not large, calculating a difference amount of the second intake air amount from the first intake air amount;
a calculation mode switching process for
setting the first intake air amount as an intake air amount calculated value of the engine when determining in the determination process that the intake pulsation is not large, and
setting a corrected second intake air amount, which is a sum of the second intake air amount and the difference amount, as the intake air amount calculated value when determining in the determination process that the intake pulsation is large; and

an injector driving process for performing a fuel injection control on an injector by determining a fuel injection amount based on the set intake air amount calculated value,
wherein the engine controller is further configured to perform learning of, in the difference amount calculation process, a difference amount learning value, which is a learning value of the difference amount, for each of difference amount learning regions divided from one another in accordance with a rotation speed of the engine.

2. The engine controller according to claim 1 , wherein the learning of the difference amount in the difference amount calculation process is configured to be performed by collectively updating the difference amount learning values in the difference amount learning regions when the learning of the difference amount is incomplete in all of the difference amount learning regions and by updating only the difference amount learning value of one of the difference amount learning regions in which the engine is currently running when the learning of the difference amount is complete in any one of the difference amount learning regions, and
wherein the engine controller is configured to:
determine whether an absolute value of a deviation amount of the learned difference amount from the current difference amount in the difference amount calculation process is less than or equal to a preset convergence determination value to determine the learning of the difference amount learning value has been completed.

3. The engine controller according to claim 1 , wherein
the learning of the difference amount in the difference amount calculation process is performed by updating the difference amount learning value based on a difference obtained by subtracting, from the difference amount, a shift correction amount calculated in accordance with the rotation speed of the engine and load of the engine, and
the corrected second intake air amount is calculated by using a sum of the difference amount learning value and the shift correction amount as a value of the difference amount.

4. The engine controller according to claim 1 , wherein
the learning of the difference amount in the difference amount calculation process is performed by updating the difference amount learning value based on a value obtained by performing environmental correction according to an environmental condition of the engine on the difference amount, and
the corrected second intake air amount is calculated by using a value obtained by performing inverse correction of the environmental correction on the difference amount learning value as a value of the difference amount.

5. The engine controller according to claim 1 , further comprising an intake pipe model for calculating a change amount of the intake pipe pressure per unit of time from the detected value of the intake air flow rate of the air flowmeter and calculating the intake pipe pressure by updating a value of the intake pipe pressure in accordance with the change amount of the intake pipe pressure per unit of time, wherein
the calculation of the first intake air amount in the first intake air amount calculation process is performed by using the intake pipe pressure calculated with the intake pipe model, and
a calculated value of the intake pipe pressure of the intake pipe model is replaced with the detected value of the intake pipe pressure or an estimated value of the intake pipe pressure that is based on the throttle opening degree when the determination of the determination process is switched from the determination that the intake pulsation is large to the determination that the intake pulsation is not large.

6. The engine controller according to claim 1 , wherein the engine controller is configured to:
learn a difference amount learning value, which is a learning value of the difference amount, by updating a value of the learning value of the difference amount in accordance with a deviation amount of the corrected second intake air amount from the first intake air amount in the difference amount calculation process;
learn the difference amount learning value according to the deviation amount in a first learning region before completion of the learning of the difference amount learning value wherein completion of the learning of the difference amount learning value is determined based on the deviation amount in the second learning region;
learn the difference amount learning value according to the deviation amount in a second learning region after completion of the learning of the difference amount learning value;
determine whether an absolute value of the deviation amount is less than or equal to a preset convergence determination value in each of preset determination cycles when the engine is running in the second learning region; and
determine, when a number of times of determining that the absolute value of the deviation amount is less than or equal to the convergence determination value becomes a preset learning complete determination value or higher, that the learning of the difference amount learning value has been completed, wherein
the first learning region includes a pulsation region, which is an engine running region where the intake pulsation occurs, and
the second learning region includes the pulsation region and is narrower than the first learning region.

7. The engine controller according to claim 6 , wherein
the difference amount learning value, the first learning region, and the second learning region are set separately for each of rotation speed regions divided in accordance with the engine rotation speed, and
whether the learning of the difference amount learning value has been completed is determined separately in each of the rotation speed regions.

8. The engine controller according to claim 6 , wherein
the first learning region is a region in which the intake pipe pressure is greater than or equal to a preset first lower limit value, and
the second learning region is a region in which the intake pipe pressure is greater than or equal to a second lower limit value, the second lower limit value being higher than the first lower limit value.

9. The engine controller according to claim 1 ,

Assignees

• Toyota Motor Co Ltd

Inventors

• Yamada Takafumi
• Shibata Hiroyuki
• Kurita Shunsuke
• Anami Takahiro

Classifications

• F02D13/0203

  Variable control of intake and exhaust valves · CPC title

• F02D2200/703

  Atmospheric pressure · CPC title

• F02D41/182 Primary

  for the control of a fuel injection device · CPC title

• F02D2041/001

  for engines with variable valve actuation · CPC title

• F02D41/18 Primary

  by measuring intake air flow · CPC title