Vehicle state sensing system and vehicle state sensing method

• US 20050201593A1
• Filed: 03/08/2005
• Published: 09/15/2005
• Est. Priority Date: 03/09/2004
• Status: Active Grant

• Current Assignee: DENSO Corporation
• Original Assignee: DENSO Corporation
• Inventors: Sawada, Mamoru, Matsumoto, Toshiki
• Granted Patent: US 7,477,760 B2
• Time in Patent Office: Days
• US Class Current: 382/104
• CPC Class Codes: B60W 40/02 related to ambient conditions
• CPC Class Codes: B60W 40/103 Side slip angle of vehicle body
• CPC Class Codes: B60W 40/105 Speed

Abstract

An on-vehicle camera captures an image of an outside visual scene that is outside of a vehicle and outputs image data of the captured image. A wheel speed sensor outputs a measurement signal, which corresponds to a moving speed of the vehicle. An ECU determines a state of the vehicle based on the measurement signal of the wheel speed sensor and an optical flow of a predetermined point of the captured image, which is captured during traveling of the vehicle. The optical flow of the predetermined point is obtained based on the image data of the captured image.

Claims

1. A vehicle state sensing system comprising:

an image recognizing means that is installed in a vehicle, wherein the image recognizing means is for capturing an image of an outside visual scene that is outside of the vehicle and is for outputting image data of the captured image;

a vehicle speed sensing means for outputting a measurement signal, which corresponds to a moving speed of the vehicle; and

a vehicle state determining means for determining a state of the vehicle based on the measurement signal of the vehicle speed sensing means and an optical flow of a predetermined point of the captured image, which is captured during traveling of the vehicle, wherein the optical flow of the predetermined point is obtained based on the image data of the captured image.

2. The vehicle state sensing system according to claim 1, wherein the vehicle state determining means determines a slip angle of the vehicle as the state of the vehicle, and the slip angle of the vehicle indicates a translational movement of the vehicle in a transverse direction of the vehicle.

3. The vehicle state sensing system according to claim 2, wherein the vehicle state determining means determines the slip angle of the vehicle using the following equation where:

4. The vehicle state sensing system according to claim 1, wherein the vehicle state determining means determines a yaw rate of the vehicle as the state of the vehicle, and the yaw rate of the vehicle indicates a rotational movement of the vehicle about a center of mass of the vehicle.

5. The vehicle state sensing system according to claim 4, wherein the vehicle state determining means determines the yaw rate of the vehicle using the following equation

6. A vehicle state sensing method comprising:

obtaining a moving speed of a vehicle;

obtaining image data of an image of an outside visual scene that is outside of the vehicle and is captured by an image recognizing means during traveling of the vehicle;

obtaining an optical flow of a predetermined point of the captured image based on the image data; and

determining a state of the vehicle based on the moving speed of the vehicle and the optical flow of the predetermined point.

7. The vehicle state sensing method according to claim 6, wherein the determining of the state of the vehicle includes determining a slip angle of the vehicle as the state of the vehicle, and the slip angle of the vehicle indicates a translational movement of the vehicle in a transverse direction of the vehicle.

8. The vehicle state sensing method according to claim 7, wherein the determining of the slip angle of the vehicle includes determining of the slip angle of the vehicle using the following equation

9. The vehicle state sensing method according to claim 6, wherein the determining of the state of the vehicle includes determining a yaw rate of the vehicle as the state of the vehicle, and the yaw rate of the vehicle indicates a rotational movement of the vehicle about a center of mass of the vehicle.

10. The vehicle state sensing method according to claim 9, wherein the determining of the yaw rate of the vehicle includes determining of the yaw rate of the vehicle using the following equation