Engine controller based on atmospheric pressure

Patent metadata

Field	Value
Publication number	US-10502156-B2
Application number	US-201515121349-A
Country	US
Kind code	B2
Filing date	Feb 25, 2015
Priority date	Feb 26, 2014
Publication date	Dec 10, 2019
Grant date	Dec 10, 2019

Abstract

An engine includes a fuel injector, an atmospheric pressure sensor, and an engine controller coupled to the fuel injector. The atmospheric pressure sensor detects the atmospheric pressure. The engine controller includes a first control device and a second control device. The first control device is configured to determine whether the engine is in a steady state or a transient state. The second control device is configured to calculate a fuel injection timing in the steady state, a the fuel injection timing in the transient state, and an atmospheric pressure correction process for correcting the fuel injection timing on the basis of the atmospheric pressure. The atmospheric correction process is performed only in the steady state to avoid redundancy. The engine controller outputs a final injection timing to the fuel injector as a result of the calculated fuel injection timing and the calculated atmospheric correction process.

First claim

The invention claimed is:

1. An engine comprising:
a fuel injector;
an atmospheric pressure sensor configured to detect an atmospheric pressure; and
an engine controller comprising a first control device and a second control device, and coupled to the fuel injector,
wherein the first control device is configured to determine whether the engine is in a steady state or a transient state,
wherein the second control device is configured to calculate a fuel injection timing in the steady state, a fuel injection timing in the transient state, and an atmospheric pressure correction process for correcting an effect of the atmospheric pressure on the fuel injection timing,
wherein the atmospheric pressure correction process is performed only in the steady state,
wherein the second control device is configured to:
when the engine is in the steady state, correct the calculated fuel injection timing in the steady state in accordance with an atmospheric pressure correction amount calculated, using the atmospheric pressure correction process; and
when the engine is in the transient state, use the calculated fuel injection timing in the transient state, and

wherein the engine controller is configured to output a final injection timing to the fuel injector.

2. The engine according to claim 1 , wherein the atmospheric pressure correction amount is calculated based on the atmospheric pressure detected by the atmospheric pressure sensor, an engine speed, and a fuel injection amount.

3. The engine according to claim 1 , wherein the first control device is configured to determine whether the engine is in the steady state or the transient state based on an amount of change of an accelerator position, an amount of change of a fuel injection amount, or an amount of change of an engine speed.

4. The engine according to claim 1 , wherein the atmospheric pressure correction amount is generated based on the atmospheric pressure detected by the atmospheric pressure sensor, an engine speed, a fuel injection amount, an atmospheric pressure correction amount map, and atmospheric pressure correction coefficient curve.

5. The engine according to claim 1 , wherein the engine controller is configured to perform the atmospheric pressure correction process by being configured to:
apply a standard injection timing map to an engine speed and a fuel injection amount to generate a standard injection timing, wherein the standard injection timing corresponds to the calculated fuel injection timing in the steady state;
apply an atmospheric pressure correction amount map to the engine speed and the fuel injection amount to generate a correction amount;
apply an atmospheric pressure correction coefficient curve to the atmospheric pressure detected by the atmospheric pressure sensor to generate a correction coefficient;
generate the atmospheric pressure correction amount based on integrating the correction amount and the correction coefficient; and
adjust the standard injection timing based on the atmospheric pressure correction amount to generate the final injection timing.

6. The engine according to claim 5 , wherein the correction amount is calculated independent of the atmospheric pressure detected by the atmospheric pressure sensor.

7. The engine according to claim 1 , wherein the final injection timing is further adjusted based on turbo lag.

8. The engine according to claim 1 , wherein the atmospheric pressure correction process is configured to determine whether or not to perform pre-injection, whether or not to perform pilot injection, an adjustment to a fuel injection amount, an adjustment to a fuel injection timing, or a combination thereof.

9. The engine according to claim 1 , wherein the atmospheric pressure correction process is configured to increase a pre-injection amount, decrease a pre-injection interval, or both.

10. An engine control system comprising:
an engine controller coupled to a fuel injector of an engine, the engine controller comprising:
a first control device configured to determine whether the engine is in a steady state or a transient state; and
a second control device configured to:
calculate a fuel injection timing in the steady state;
calculate a fuel injection timing in the transient state;
calculate an atmospheric pressure correction amount according to an atmospheric pressure correction process for correcting an effect of atmospheric pressure on the fuel injection timing in the steady state; and
output, to the fuel injector, a final fuel injection timing based on at least one of the fuel injection timing in the steady state, the fuel injection timing in the transient state, or the atmospheric pressure correction amount; and

an atmospheric pressure sensor coupled to the engine controller and configured to detect the atmospheric pressure; and
wherein, when the engine is in the transient state and when the atmospheric pressure detected by the atmospheric pressure sensor is less than or equal to a first threshold and is greater than or equal to a second threshold that is less than the first threshold, the second control device is configured to use the calculated fuel injection timing in the transient state as the final fuel injection timing.

11. The engine control system according to claim 10 , further comprising:
the engine including one or more cylinders; and
the fuel injector configured to inject fuel, based on the final fuel injection timing, into a cylinder of the one or more cylinders.

12. The engine control system according to claim 10 , wherein, when the engine is in the steady state, the second control device is configured to:
correct the fuel injection timing in the steady state based on the atmospheric pressure correction amount to determine a corrected fuel injection timing in the steady state; and
use the corrected fuel injection timing in the steady state as the final fuel injection timing.

13. An engine control system comprising:
an engine controller coupled to a fuel injector of an engine, the engine controller configured to:
calculate a steady state fuel injection timing;
calculate a transient state fuel injection timing;
calculate an atmospheric pressure correction amount according to an atmospheric pressure correction process for correcting an effect of atmospheric pressure on the steady state fuel injection timing; and
output, to the fuel injector, a final fuel injection timing based on at least one of the steady state fuel injection timing, the transient state fuel injection timing, or the atmospheric pressure correction amount;

wherein the engine controller is further configured to:
when the engine is in a transient state and when the atmospheric pressure is less than or equal to a first threshold and when the atmospheric pressure is greater than or equal to a second threshold, use the calculated transient state fuel injection timing as the final fuel injection timing, wherein the first threshold is greater than the second threshold; and
when the engine is in the transient state and when the atmospheric pressure is greater than the first threshold or the atmospheric pressure is less than the second threshold, correct the fuel injection timing in accordance with a second atmospheric pressure correction process, different from the atmospheric pressure correction process, to generate the final fuel injection timing.

14. The engine control system according to claim 13 , wherein:
when the engine is in a steady state, the engine controller is configured to:
correct the steady state fuel injection timing based on the atmospheric pressure correction amount to determine a corrected stead

Assignees

• Yanmar Co Ltd

Inventors

• Otani Tomohiro
• Iwase Atsuhito

Classifications

• F02D41/1448

  the characteristics being an exhaust gas pressure · CPC title

• F02D41/3011 Primary

  according to or using specific or several modes of combustion · CPC title

• F02D41/401 Primary

  Controlling injection timing (F02D41/402 takes precedence) · CPC title

• F02D41/2422

  Selective use of one or more tables · CPC title

• F02D41/1446

  the characteristics being exhaust temperatures · CPC title