Method and system for selecting an engine operating point for a hybrid vehicle

Patent metadata

Field	Value
Publication number	US-9145133-B2
Application number	US-201314075356-A
Country	US
Kind code	B2
Filing date	Nov 8, 2013
Priority date	Nov 8, 2013
Publication date	Sep 29, 2015
Grant date	Sep 29, 2015

Abstract

A vehicle includes a powertrain having an engine and an electric machine (M/G) connected by an upstream clutch, and a gearbox connected to the M/G by a torque converter. A controller is configured to, in response to a Park or Neutral gear selection and an electrical power request from the M/G, operate the engine at an engine speed and an engine torque based on the request and M/G speed and torque for improved powertrain efficiency. A method is provided for controlling a vehicle. In response to a Park or Neutral gear selection and an electrical power request from the M/G, the engine is operated at an engine speed and an engine torque based on the request and M/G speed and torque for improved powertrain efficiency.

First claim

What is claimed is:

1. A vehicle comprising:
a powertrain having an engine and an electric machine (M/G) connected by an upstream clutch;
a gearbox connected to the M/G by a torque converter; and
a controller configured to, in response to a Park or Neutral gear selection and an electrical power request from the M/G, operate the engine at an engine speed and an engine torque based on the request and M/G speed and torque for improved powertrain efficiency.

2. The vehicle of claim 1 wherein the controller is further configured to, in response to a Park or Neutral gear selection and an electrical power request from the M/G, operate the M/G as a generator.

3. The vehicle of claim 2 wherein the controller is further configured to, in response to a Park or Neutral gear selection and an electrical power request from the M/G, operate the M/G at a torque output generally equal to torque losses in the torque converter minus the engine torque.

4. The vehicle of claim 1 wherein the controller is further configured to, in response to a Park or Neutral gear selection and an electrical power request from the M/G, lock the upstream clutch.

5. The vehicle of claim 4 wherein the controller is further configured to, in response to a Park or Neutral gear selection and an electrical power request from the M/G, operate the M/G at the engine speed.

6. The vehicle of claim 1 wherein the powertrain efficiency comprises an efficiency of the engine, an efficiency of the M/G, and an efficiency of the torque converter.

7. The vehicle of claim 1 wherein the gearbox comprises a park mechanism, and
wherein the controller is further configured to receive a signal indicative of the park mechanism being engaged to determine the gear selection.

8. The vehicle of claim 1 wherein the gearbox comprises a shifting clutch, and
wherein the controller is further configured to receive a signal indicative of the shifting clutch being disengaged to determine the gear selection.

9. The vehicle of claim 1 wherein the gearbox is an automatic, step ratio transmission gearbox.

10. A method for controlling a vehicle having an engine selectively coupled to an electric machine (M/G) by an upstream clutch with the M/G selectively coupled to a step ratio gearbox by a torque converter, comprising, in response to a Park or Neutral gear selection and an electrical power request from the M/G, operating the engine at an engine speed and engine torque based on the request and M/G speed and torque for improved powertrain efficiency.

11. The method of claim 10 further comprising, in response to a Park or Neutral gear selection and an electrical power request from the M/G, operating the M/G as a generator at a torque output generally equal to torque losses in the torque converter minus the engine torque.

12. The method of claim 10 further comprising, in response to a Park or Neutral gear selection and an electrical power request from the M/G, engaging the upstream clutch such that the M/G operates at the engine speed.

13. The method of claim 10 wherein the engine speed and engine torque are selected as a (ω e *, τ e *) target value based on a solution for an optimized powertrain efficiency that satisfies the request for electrical power from the M/G and incorporates an efficiency of the engine, an efficiency of the M/G, and an efficiency of the torque converter.

14. The method of claim 13 wherein the solution for an optimized powertrain efficiency is limited by a threshold value for engine torque and a threshold value for engine speed to reduce noise and vibration from the engine.

15. The method of claim 13 wherein the solution for an optimized powertrain efficiency is limited by a threshold value for engine torque when the vehicle is above an altitude.

16. The method of claim 10 further comprising receiving a signal indicative of a parking mechanism being engaged to determine the gear selection.

17. The method of claim 10 further comprising receiving a signal indicative of a shifting clutch being disengaged to determine the gear selection.

Assignees

• Ford Global Tech Llc

Inventors

• Liang Wei
• Yamazaki Mark Steven
• Wang Xiaoyong
• Johri Rajit
• Mcgee Ryan Abraham
• Kuang Ming Lang

Classifications

• Y02T10/62

  Hybrid vehicles · CPC title

• B60W10/06 Primary

  including control of combustion engines · CPC title

• B60W10/08

  including control of electric propulsion units, e.g. motors or generators · CPC title

• B60W20/108 Primary

  Operations & Transport · mapped topic

• Y10S903/93

  Conjoint control of different elements · CPC title