Methods and system for starting an engine of a hybrid vehicle

Patent metadata

Field	Value
Publication number	US-2016031435-A1
Application number	US-201414449759-A
Country	US
Kind code	A1
Filing date	Aug 1, 2014
Priority date	Aug 1, 2014
Publication date	Feb 4, 2016
Grant date	—

Abstract

Systems and methods for starting an engine of a hybrid vehicle are disclosed. The systems and methods disclosed may apply to series or parallel hybrid driveline configurations. In one example, engine cranking torque may be adjusted in response to a variety of operating conditions so that the engine may be started faster or slower.

First claim

1 . A driveline method, comprising:
estimating a driveline integrated starter/generator torque reserve; supplying a first torque to start an engine in response to the driveline integrated starter/generator torque reserve being less than a threshold; and supplying a second torque, different from the first torque, to start the engine in response to the driveline integrated starter/generator torque reserve being greater than a threshold.

2 . The method of claim 1 , where the driveline integrated starter/generator torque reserve is a torque capacity of the driveline integrated starter/generator torque reserve at a present driveline speed minus a present driveline integrated starter/generator torque reserve output torque.

3 . The method of claim 2 , further comprising reducing the driveline integrated starter/generator torque reserve in response to a steering angle.

4 . The method of claim 2 , further comprising reducing the driveline integrated starter/generator torque reserve in response to vehicle mass.

5 . The method of claim 2 , further comprising reducing the driveline integrated starter/generator torque reserve in response to road grade.

6 . The method of claim 2 , further comprising reducing the driveline integrated starter/generator torque reserve in response to vehicle speed being greater than a non-zero speed threshold.

7 . The method of claim 2 , further comprising reducing the driveline integrated starter/generator torque reserve in response to an indication of towing a trailer.

8 . The method of claim 1 , where the first torque is sufficient to accelerate the engine to a speed of a driveline integrated starter/generator.

9 . The method of claim 8 , where the second torque is insufficient to accelerate the engine to the speed of the driveline integrated starter/generator.

10 . A driveline method, comprising:
supplying a first torque to start an engine in response to a first condition of a road; and supplying a second torque, different from the first torque, to start the engine in response to a second condition of the road.

11 . The method of claim 10 , where the first torque is sufficient to accelerate the engine to a speed of a driveline integrated starter/generator.

12 . The method of claim 11 , where the second torque is insufficient to accelerate the engine to the speed of the driveline integrated starter/generator.

13 . The method of claim 10 , where the condition of the road is a road grade.

14 . The method of claim 10 , where the condition of the road is arrival at an intersection.

15 . The method of claim 14 , where the intersection is a rail road intersection.

16 . The method of claim 10 , where the condition of the road is a road roughness amount.

17 . A driveline system, comprising:
an engine; an electric machine; a driveline disconnect clutch positioned between the engine and the electric machine; and a controller including executable instructions stored in non-transitory memory for starting the engine via the electric machine in a first mode where engine cranking torque is sufficient to accelerate the engine to a speed of the electric machine, starting the engine in a second mode where engine cranking torque is insufficient to accelerate the engine to the speed of the electric machine, and adjusting slip of the driveline disconnect clutch to provide engine cranking torque in the first and second modes.

18 . The driveline system of claim 17 , further comprising additional instructions to estimate a driveline integrated starter/generator torque reserve and enter the first or second mode based on the driveline integrated starter/generator torque reserve.

19 . The driveline system of claim 17 , further comprising additional instructions to enter the first or second mode based on a condition of a road.

20 . The driveline system of claim 17 , where the condition of the road is a road grade.

Assignees

• Ford Global Tech Llc

Inventors

• Gibson Alexander O'Connor
• Nedorezov Felix
• Lee Seunghoon
• Doering Jeffrey Allen
• Jiang Hong

Classifications

• B60W20/12

  using control strategies taking into account route information {(estimation or calculation of non-directly measurable driving parameters B60W40/00)} · CPC title

• F02N11/04

  the motors being associated with current generators · CPC title

• B60W10/08

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

• Y10S903/93

  Conjoint control of different elements · CPC title

• B60W2710/085

  Torque change rate · CPC title