Method and apparatus for emissions mitigation on a hybrid vehicle

Patent metadata

Field	Value
Publication number	US-11305752-B2
Application number	US-201916671945-A
Country	US
Kind code	B2
Filing date	Nov 1, 2019
Priority date	Nov 1, 2019
Publication date	Apr 19, 2022
Grant date	Apr 19, 2022

Abstract

A system for emissions mitigation for a hybrid automobile vehicle includes an automobile vehicle provided with motive power from: a battery pack; an engine; and a controller in communication with the battery pack and the engine. A threshold battery pack state-of-charge (SOC) is predetermined. A minimum battery pack SOC is less than the threshold battery pack SOC. An engine-on charge depletion (EOCD) command is issued by the controller to start the engine in an engine-catalyst light-off operation condition when the vehicle is operating using power from the battery pack and when the threshold battery pack state-of-charge (SOC) is reached to mitigate against exceeding vehicle emissions standards.

First claim

What is claimed is:

1. An emissions mitigation system of a hybrid automobile vehicle, comprising:
an automobile vehicle provided with motive power from:
a battery pack; and
an engine;

a predetermined threshold battery pack state-of-charge (SOC); and
an engine-on charge depletion (EOCD) command issued to start the engine in an engine-catalyst light-off operation condition when the automobile vehicle is operating using power from the battery pack and when the threshold battery pack state-of-charge (SOC) is reached to mitigate against exceeding vehicle emissions standards.

2. The emissions mitigation system of a hybrid automobile vehicle of claim 1 , wherein the battery pack has a minimum battery pack SOC less than the threshold battery pack SOC.

3. The emissions mitigation system of a hybrid automobile vehicle of claim 2 , wherein the minimum battery pack SOC is approximately 16% SOC.

4. The emissions mitigation system of a hybrid automobile vehicle of claim 3 , wherein the threshold battery pack state-of-charge (SOC) is approximately 25% SOC.

5. The emissions mitigation system of a hybrid automobile vehicle of claim 1 , further including an engine controller, the engine controller collecting data including an ambient temperature, battery capability changes and a battery pack SOC, and storing predetermined values for a minimum threshold temperature T 1 and the threshold battery pack state-of-charge (SOC).

6. The emissions mitigation system of a hybrid automobile vehicle of claim 5 , wherein the engine controller includes a command signal generator to signal automatic start and stop of the engine.

7. The emissions mitigation system of a hybrid automobile vehicle of claim 1 , wherein the engine-catalyst light-off operation condition defines an engine speed ranging between an idle rpm up to approximately 1500 rpm.

8. The emissions mitigation system of a hybrid automobile vehicle of claim 1 , wherein a time period to operate at the engine-catalyst light-off operation condition is approximately two minutes.

9. The emissions mitigation system of a hybrid automobile vehicle of claim 1 , wherein a minimum limit for operation at the engine-catalyst light-off operation condition is until an engine minimum threshold temperature of approximately 60 degrees C. is reached.

10. The emissions mitigation system of a hybrid automobile vehicle of claim 1 , further including a charge depletion/charge sustaining (CD-CS) transition point P 1 of the battery pack of approximately 16% SOC defining a minimum battery pack SOC for battery pack use.

11. A emissions mitigation system of a hybrid automobile vehicle, comprising:
an automobile vehicle provided with motive power from:
a battery pack;
an engine; and
a controller in communication with the battery pack and the engine;

a predetermined threshold battery pack state-of-charge (SOC);
a minimum battery pack SOC less than the threshold battery pack SOC; and
an engine-on charge depletion (EOCD) command issued by the controller to start the engine in an engine-catalyst light-off operation condition when the automobile vehicle is operating using power from the battery pack and when the threshold battery pack state-of-charge (SOC) is reached to mitigate against exceeding vehicle emissions standards.

12. The emissions mitigation system of a hybrid automobile vehicle of claim 11 , further including a minimum engine threshold temperature of approximately 60 degrees C. wherein upon achieving the minimum engine threshold temperature the engine-catalyst light-off operation condition is discontinued.

13. The emissions mitigation system of a hybrid automobile vehicle of claim 12 , wherein a cold start emissions reduction (CSER) is complete when the engine achieves the minimum engine threshold temperature.

14. The emissions mitigation system of a hybrid automobile vehicle of claim 13 , further including a charge sustaining operation of the automobile vehicle wherein greenhouse gas emissions and soot do not exceed emission standards when the engine becomes a primary energy source.

15. The emissions mitigation system of a hybrid automobile vehicle of claim 12 , further including a temperature sensor measuring an engine coolant temperature to identify the minimum engine threshold temperature.

16. The emissions mitigation system of a hybrid automobile vehicle of claim 11 , wherein the minimum battery pack SOC defines a charge-depletion/charge-sustaining (CD-CS) transition point P 1 where transition from vehicle powered operation using the battery pack is changed to vehicle powered operation using the engine.

17. The emissions mitigation system of a hybrid automobile vehicle of claim 11 , wherein:
the minimum battery pack SOC is approximately 16% SOC; and
the threshold battery pack state-of-charge (SOC) ranges from approximately 20% up to approximately 35% inclusive.

18. A method of operating an emissions mitigation system of a hybrid automobile vehicle, comprising:
measuring battery metrics of a battery pack during operation of the automobile vehicle using power of the battery pack;
confirming if a capability reduction of the battery pack has occurred;
if a response to the confirming step is YES indicating a capability reduction of the battery pack has occurred, identifying a state-of-charge (SOC) transition point and an adjusted SOC transition point defining a threshold battery pack SOC;
automatically starting an engine when the threshold battery pack SOC is reached before a charge-depletion/charge-sustaining transition point defining the SOC transition point is reached; and
operating the engine “shielded” defined as the engine not supporting a vehicle load demand until the engine reaches a predetermined minimum threshold temperature.

19. The method of operating the emissions mitigation system of a hybrid automobile vehicle of claim 18 , further including:
selecting the threshold battery pack state-of-charge (SOC) of approximately 25% defining an adjusted SOC transition point; and
transitioning from operation of the automobile vehicle using power of the battery pack to operation of the automobile vehicle using power of the engine when the adjusted SOC transition point is reached.

20. The method of operating the emissions mitigation system of a hybrid automobile vehicle of claim 19 , further including performing a cold start emissions reduction (CSER) catalyst light-off (CLO) with the engine operated in a light operation mode including limiting an engine speed between an idle rpm speed and approximately 1500 rpm until the engine reaches a predetermined minimum threshold temperature.

Assignees

• Gm Global Tech Operations Llc

Inventors

• Piper Eric D
• Zettel Andrew M
• Heap Anthony H

Classifications

• F02N11/00

  Starting of engines by means of electric motors · CPC title

• Y02T10/12

  Improving ICE efficiencies · CPC title

• B60W2510/244

  Charge state · CPC title

• Y02T90/16

  Information or communication technologies improving the operation of electric vehicles · CPC title

• F02D2200/021

  Engine temperature · CPC title