Method of controlling posture of vehicle

Patent metadata

Field	Value
Publication number	US-2021039493-A1
Application number	US-202016927383-A
Country	US
Kind code	A1
Filing date	Jul 13, 2020
Priority date	Aug 7, 2019
Publication date	Feb 11, 2021
Grant date	—

Abstract

A method of controlling posture of a vehicle is provided to determine a minute tendency of understeer or oversteer of the vehicle and to control the posture of the vehicle when recognizing the minute tendency of the understeer or oversteer while driving the vehicle straight. The includes determining whether torque is applied to drive wheels while driving the vehicle and acquiring equivalent inertia information of a drive system in real time based on drive system operation information in response to determining that the torque is being applied to the drive wheels. The understeer or oversteer of the vehicle is determined from the equivalent inertia information obtained in real-time.

First claim

What is claimed is:

1 . A method of controlling posture of a vehicle, comprising:
determining, by a controller, whether torque is applied to drive wheels while driving the vehicle; acquiring, by the controller, equivalent inertia information of a drive system in real time based on drive system operation information in response to determining that the torque is being applied to the drive wheels; and determining, by the controller, understeer or oversteer of the vehicle from the equivalent inertia information obtained in real time.

2 . The method of controlling posture of a vehicle of claim 1 , wherein the determining of whether the torque is applied to the drive wheels includes determining that the torque is applied to the drive wheels when a torque command for a drive device for driving the vehicle is greater than a predetermined command reference value.

3 . The method of controlling posture of a vehicle of claim 1 , wherein the vehicle is a four-wheel-drive vehicle having a front-wheel-drive motor and a rear-wheel-drive motor as drive devices for driving the vehicle.

4 . The method of controlling posture of a vehicle of claim 1 , wherein the vehicle is a front-wheel-drive vehicle having a front-wheel-drive motor as a drive device for driving the vehicle, or a rear-wheel-drive vehicle having a rear-wheel-drive motor as the drive device for driving the vehicle.

5 . The method of controlling posture of a vehicle of claim 1 , wherein the drive system operation information is information of a drive system speed and a torque command in a previous control period for a drive device for driving the vehicle.

6 . The method of controlling posture of a vehicle of claim 5 , wherein the drive system speed is one of speeds of the drive wheels, a speed of the drive device, a transmission input shaft rotational speed, and a transmission output shaft rotational speed.

7 . The method of controlling posture of a vehicle of claim 1 , wherein the vehicle is a four-wheel-drive vehicle having a front-wheel drive device and a rear-wheel drive device as the drive devices for driving the vehicle, and the equivalent inertia information of the drive system includes a variation of equivalent inertia of a front-wheel side obtained in real time from operational information of a front-wheel-side drive system and a variation of equivalent inertia of a rear-wheel side obtained in real time from operation information of a rear-wheel-side drive system.

8 . The method of controlling posture of a vehicle of claim 7 , further comprising: determining the understeer or the oversteer of the vehicle in response to determining that a difference between the variation of the equivalent inertia of the front-wheel side and the variation of the equivalent inertia of the rear-wheel side is greater than a predetermined difference reference value.

9 . The method of controlling posture of a vehicle of claim 8 , further comprising:
determining, by the controller, the understeer in response to determining that the difference as a result of subtracting the variation of the equivalent inertia of the rear-wheel side from the variation of the equivalent inertia of the front-wheel side is greater than a predetermined first difference reference value; and determining, by the controller, the oversteer in response to determining that the difference as a result of subtracting the variation of the equivalent inertia of the front-wheel side from the variation of the equivalent inertia of the rear-wheel side is greater than a predetermined second difference reference value.

10 . The method of controlling posture of a vehicle of claim 1 , wherein the vehicle is a front-wheel-drive vehicle having a front-wheel drive device as a drive device for driving the vehicle, and the equivalent inertia information of the drive system includes a variation of equivalent inertia of a front-wheel side obtained in real time from operational information of a front-wheel-side drive system.

11 . The method of controlling posture of a vehicle of claim 10 , further comprising determining the understeer in response to determining that the variation of the equivalent inertia of the front-wheel side is greater than a predetermined variation reference value.

12 . The method of controlling posture of a vehicle of claim 1 , wherein the vehicle is arear-wheel-drive vehicle having arear-wheel drive device as a drive device for driving the vehicle, and the equivalent inertia information of the drive system includes a variation of equivalent inertia of arear-wheel side obtained in real time from operational information of arear-wheel-side drive system.

13 . The method of controlling posture of a vehicle of claim 12 , further comprising determining the oversteer in response to determining that the variation of the equivalent inertia of the rear-wheel side is greater than a predetermined variation reference value.

14 . The method of controlling posture of a vehicle of claim 1 , further comprising:
performing, by the controller, a correction to reduce a torque command for a drive device for driving the vehicle in response to determining the understeer or the oversteer; and adjusting, by the controller, an operation of the drive device according to a corrected torque command.

15 . The method of controlling posture of a vehicle of claim 14 , wherein the performing of the correction to reduce the torque command, includes performing the correction to reduce the torque command for a front-wheel drive device in response to determining the understeer and performing the correction to reduce the torque command for arear-wheel drive device in response to determining the oversteer.

16 . The method of controlling posture of a vehicle of claim 14 , wherein a torque correction to reduce the torque command is determined based on the equivalent inertia information of a drive system.

17 . The method of controlling posture of a vehicle of claim 16 , wherein the vehicle is a four-wheel-drive vehicle having a front-wheel drive device and arear-wheel drive device as the drive devices for driving the vehicle, and the equivalent inertia information of the drive system to determine the torque correction includes a variation of equivalent inertia of a front-wheel side obtained in real time from operational information of a front-wheel-side drive system and a variation of equivalent inertia of arear-wheel side obtained in real time from operation information of arear-wheel-side drive system.

18 . The method of controlling posture of a vehicle of claim 17 , further comprising determining the torque correction amount based on a difference between the variation of the equivalent inertia of the front-wheel side and the variation of the equivalent inertia of the rear-wheel side.

19 . The method of controlling posture of a vehicle of claim 16 , wherein the vehicle is a front-wheel-drive vehicle having a front-wheel drive device as the drive device for driving the vehicle, and the equivalent inertia information of the drive system to determine the torque correction includes a variation of equivalent inertia of a front-wheel side obtained in real time from operational information of a front-wheel-side drive system.

20 . The method of controlling posture of a vehicle of claim 16 , wherein the vehicle is arear-wheel-drive vehicle having arear-wheel drive device as the drive device for driving the vehicle, and the equivalent inertia information of the drive system to determine the torque correction includes a variation of eq

Assignees

• Hyundai Motor Co Ltd
• Kia Motors Corp

Inventors

• Oh Ji Won
• Eo Jeong Soo

Classifications

• B60L15/2036

  Electric differentials, e.g. for supporting steering vehicles · CPC title

• B60L15/00

  Methods, circuits, or devices for controlling the traction-motor speed of electrically-propelled vehicles · CPC title

• B60L3/106

  for maintaining or recovering the adhesion of the drive wheels · CPC title

• B60G2800/246

  Understeer · CPC title

• B60G2800/01

  Attitude or posture control · CPC title