Method of adaptive control for engine transient mitigation in a hybrid vehicle

• US 9,193,350 B2
• Filed: 04/05/2012
• Issued: 11/24/2015
• Est. Priority Date: 04/05/2012
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Wang, Qing, Syed, Fazal Urrahman, Kuang, Ming Lang
• Primary Examiner(s): To, Tuan C.
• Application Number:
  US13/439,930
• Publication Number:
  US 20130268175A1
• Time in Patent Office: 1,328 Days
• Field of Search: 701/22
• US Class Current: 1/1
• CPC Class Codes: B60K 6/52 Driving a plurality of drive axles, e.g. four-wheel drive
• CPC Class Codes: B60W 10/06 including control of combustion engines
• CPC Class Codes: B60W 20/10 Controlling the power contribution of each of the prime movers to meet required power demand
• CPC Class Codes: B60W 2510/0666 Engine power
• CPC Class Codes: Y02T 10/62 Hybrid vehicles

Abstract

A hybrid vehicle and method of control are provided. An engine raw power command is quantized. The quantized power command is set to one of a plurality of quantized power steps. A step size between the quantized power steps varies based on the raw power command. The engine of the hybrid vehicle is operated based on the set quantized power command.

Claims

1. A method of operating a hybrid vehicle comprising:

converting a raw power command for an engine into a quantized power command;

selecting one of a plurality of quantized power steps to meet the quantized power command,

wherein a step size between the quantized power steps varies based on the raw power command; and

operating the engine at the quantized power step selected.

2. The method of claim 1 further comprising:

operating the engine at a second quantized power step if the quantized power command falls between a first quantized power step and the second quantized power step and varies by more than a threshold value from the first quantized power step.

3. The method of claim 2 further comprising:

operating the engine at the first quantized power step if the quantized power command falls between the first and the second quantized power steps and varies less than a threshold value from the first quantized power step.

4. The method of claim 2 wherein:

the threshold value varies in an inverse relationship based on the raw power command such that the threshold value is smaller for a greater raw power command than for a smaller raw power command.

5. The method of claim 2 wherein:

the threshold value varies based on the raw power command.

6. The method of claim 2 wherein:

the threshold value comprises an upper threshold value and a lower threshold value which vary based on the raw power command.

7. The method of claim 1 wherein:

the step size varies based on the raw power command in an inverse relationship such that the step size is smaller for a greater raw power command than for a lesser raw power command.

8. The method of claim 1 further comprising:

selecting a first set of quantized power steps, wherein a first step size between the first set of quantized power steps is based on a first raw power command; and

selecting a second set of quantized power steps, wherein a second step size between the second set of quantized power steps is based on a second raw power command and is different than the first step size.

9. A hybrid vehicle control system comprising:

an engine;

an electric-machine; and

a powertrain controller programmed to;

convert a raw power command for the engine into a quantized power command; and

request the engine operate at a power level selected from one of a plurality of quantized power steps to meet the quantized power command,

wherein a step size between the quantized power steps varies based on the raw power command.

10. The hybrid vehicle control system of claim 9 wherein the controller is further configured to request the engine operate at a second quantized power step if the quantized power command falls between a first quantized power step and the second quantized power step and varies by more than a threshold value from the first quantized power step.

11. The hybrid vehicle control system of claim 10:

wherein the controller is further configured to request the engine operate at the first quantized power step if the quantized power command falls between the first and the second quantized power steps and varies less than a threshold value from the first quantized power step.

12. The hybrid vehicle control system of claim 10 wherein:

the threshold value varies in an inverse relationship based on the raw power command such that the threshold value is smaller for a greater raw power command than for a smaller raw power command.

13. The hybrid vehicle control system of claim 10 wherein:

the threshold value varies based on the raw power command.

14. The hybrid vehicle control system of claim 10 wherein:

the threshold value comprises an upper threshold value and a lower threshold value which vary based on the raw power command.

15. The hybrid vehicle control system of claim 9 wherein:

the step size varies based on the raw power command in an inverse relationship such that the step size is smaller for a greater raw power command than for a lesser raw power command.

16. The hybrid vehicle control system of claim 9 wherein the controller is further configured to:

request the engine operate at a first power level selected from a first set of quantized power steps, wherein a first step size between the first set of quantized power steps is based on a first raw power command; and

request the engine operate at a second power level selected from a second set of quantized power steps, wherein a second step size between the second set of quantized power steps is based on a second raw power command and is different than the first step size.

17. A method of operating a hybrid vehicle comprising:

converting a previous power command for an engine into a previous quantized power command;

operating the engine at a first power level selected from one of a plurality of previous quantized power steps having a first step size between each of the previous quantized power steps;

converting a current power command for an engine into a current quantized power command; and

operating the engine at a second power level selected from one of a plurality of current quantized power steps having a second step size between each of the current quantized power steps, the second step size being different from the first step size.

18. The method of claim 17 further comprising:

maintaining the current quantized power command if difference between the current power command and the quantized previous power command is larger than a threshold and otherwise setting the current quantized power command equal to the previous quantized power command.

19. The method of claim 17 further comprising:

during a tip-in event, maintaining the current quantized power command if the current power command is larger than the sum of the quantized previous power command and an upper threshold value; and

during the tip-in event, setting the quantized current engine power command equal to the previous quantized engine power command if the current engine power command is smaller than the sum of the quantized previous engine power command and the threshold value.

20. The method of claim 17 further comprising:

during a tip-out event, maintaining the current quantized engine power command if the current engine power command is smaller than the quantized previous engine power command subtracted by a lower threshold value; and

during the tip-out event, setting the quantized current power command equal to the previous quantized power command if the current power command is larger than the previous quantized power command subtracted by the lower threshold value.