Vehicle control system

Patent metadata

Field	Value
Publication number	US-11607953-B2
Application number	US-202117405584-A
Country	US
Kind code	B2
Filing date	Aug 18, 2021
Priority date	Aug 24, 2020
Publication date	Mar 21, 2023
Grant date	Mar 21, 2023

Abstract

A vehicle control system to be mounted in a hybrid electric vehicle includes an engine, a center differential that includes a front-wheel-side output portion and a rear-wheel-side output portion and distributes torque outputted from the engine to a front wheel and a rear wheel, a limited slip differential mechanism that limits a differential between the front-wheel-side output portion and the rear-wheel-side output portion, and a motor disposed in a drive-power transferring system that transfers drive power from the rear-wheel-side output portion to the rear wheel. The vehicle control system includes a processor. When the hybrid electric vehicle is switched from a first traveling mode to a second traveling mode, the processor stops the engine while causing the limited slip differential mechanism to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion.

First claim

The invention claimed is:

1. A vehicle control system to be mounted in a hybrid electric vehicle, the hybrid electric vehicle including:
an engine;
a center differential including a front-wheel-side output portion and a rear-wheel-side output portion and configured to distribute torque outputted from the engine to a front wheel and a rear wheel;
a limited slip differential mechanism configured to limit a differential between the front-wheel-side output portion and the rear-wheel-side output portion; and
a motor disposed in a drive-power transferring system configured to transfer drive power from the rear-wheel-side output portion to the rear wheel,
the vehicle control system comprising
a processor configured to, when the hybrid electric vehicle is switched from a first traveling mode in which the engine and the motor are both used as drive sources to a second traveling mode in which only the motor out of the engine and the motor is used as a drive source, stop the engine while causing the limited slip differential mechanism to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion.

2. The vehicle control system according to claim 1 , wherein
the processor is configured to stop the engine while causing the limited slip differential mechanism to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion, and thereafter perform rear-wheel drive switching control to switch the hybrid electric vehicle to a rear-wheel drive state by relaxing the differential limited by the limited slip differential mechanism.

3. The vehicle control system according to claim 2 , wherein
the processor is configured to perform the rear-wheel drive switching control on a basis of a result of an estimation of a road surface condition.

4. The vehicle control system according to claim 3 , wherein
the processor is configured to determine whether to perform the rear-wheel drive switching control on a basis of the result of the estimation of the road surface condition.

5. The vehicle control system according to claim 2 , wherein
the processor is configured to
calculate a required front-rear torque distribution value on a basis of data indicating a traveling state of the hybrid electric vehicle, the required front-rear torque distribution value comprising a value required in distribution of the torque between the front wheel and the rear wheel, and
perform the rear-wheel drive switching control on a basis of the required front-rear torque distribution value.

6. The vehicle control system according to claim 3 , wherein
the processor is configured to
calculate a required front-rear torque distribution value on a basis of data indicating a traveling state of the hybrid electric vehicle, the required front-rear torque distribution value comprising a value required in distribution of the torque between the front wheel and the rear wheel, and
perform the rear-wheel drive switching control on a basis of the required front-rear torque distribution value.

7. The vehicle control system according to claim 4 , wherein
the processor is configured to
calculate a required front-rear torque distribution value on a basis of data indicating a traveling state of the hybrid electric vehicle, the required front-rear torque distribution value comprising a value required in distribution of the torque between the front wheel and the rear wheel, and
perform the rear-wheel drive switching control on a basis of the required front-rear torque distribution value.

8. The vehicle control system according to claim 1 , wherein the processor is configured to
determine whether the hybrid electric vehicle is traveling straight when the hybrid electric vehicle is switched from the first traveling mode to the second traveling mode, and
stop the engine while causing the limited slip differential mechanism not to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion in a case where the hybrid electric vehicle is determined to be traveling straight.

9. The vehicle control system according to claim 2 , wherein the processor is configured to
determine whether the hybrid electric vehicle is traveling straight when the hybrid electric vehicle is switched from the first traveling mode to the second traveling mode, and
stop the engine while causing the limited slip differential mechanism not to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion in a case where the hybrid electric vehicle is determined to be traveling straight.

10. The vehicle control system according to claim 3 , wherein the processor is configured to
determine whether the hybrid electric vehicle is traveling straight when the hybrid electric vehicle is switched from the first traveling mode to the second traveling mode, and
stop the engine while causing the limited slip differential mechanism not to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion in a case where the hybrid electric vehicle is determined to be traveling straight.

11. The vehicle control system according to claim 4 , wherein the processor is configured to
determine whether the hybrid electric vehicle is traveling straight when the hybrid electric vehicle is switched from the first traveling mode to the second traveling mode, and
stop the engine while causing the limited slip differential mechanism not to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion in a case where the hybrid electric vehicle is determined to be traveling straight.

12. The vehicle control system according to claim 5 , wherein the processor is configured to
determine whether the hybrid electric vehicle is traveling straight when the hybrid electric vehicle is switched from the first traveling mode to the second traveling mode, and
stop the engine while causing the limited slip differential mechanism not to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion in a case where the hybrid electric vehicle is determined to be traveling straight.

13. The vehicle control system according to claim 6 , wherein the processor is configured to
determine whether the hybrid electric vehicle is traveling straight when the hybrid electric vehicle is switched from the first traveling mode to the second traveling mode, and
stop the engine while causing the limited slip differential mechanism not to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion in a case where the hybrid electric vehicle is determined to be traveling straight.

14. The vehicle control system according to claim 7 , wherein the processor is configured to
determine whether the hybrid electric vehicle is traveling straight when the hybrid electric vehicle is switched from the first traveling mode to the second traveling mode, and
stop the engine while causing the limited slip differential mechanism not to limit the differential between the front-wheel-side output portion and the rear-wheel-side output portion in a case where the hybrid electric vehicle is determined to be traveling straight.

Assignees

• Subaru Corp

Inventors

• Hirosumi Naohiko
• Inoue Satoshi
• Akiyama Hiroyuki

Classifications

• B60W2520/14

  Yaw · CPC title

• B60W2552/40

  Coefficient of friction · CPC title

• B60K17/356

  having fluid or electric motor, for driving one or more wheels · CPC title

• B60W2710/0666

  Engine torque · CPC title

• B60W10/06

  including control of combustion engines · CPC title