Device and method for traffic sign recognition

• US 9,070,293 B2
• Filed: 08/23/2012
• Issued: 06/30/2015
• Est. Priority Date: 08/24/2011
• Status: Active Grant

• Current Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Original Assignee: Ford Global Technologies, LLC (Ford Motor Company)
• Inventors: Roeber, Marc, Gunia, Dirk, Wey, Torsten, Doerne, Gerald
• Primary Examiner(s): Nguyen, Tai T
• Assistant Examiner(s): Wu, Zhen Y
• Application Number:
  US13/593,032
• Publication Number:
  US 20130049988A1
• Time in Patent Office: 1,041 Days
• Field of Search: 340/905, 340/917
• US Class Current: 1/1
• CPC Class Codes: G08G 1/09623 Systems involving the acquisition of information from passive traffic signs by means mounted on the vehicle G08G1/0967 takes precedence
• CPC Class Codes: G08G 1/0967 Systems involving transmission of highway information, e.g. weather, speed limits transmission of navigation instructions to the vehicle G08G1/0968

Abstract

A method and apparatus for determining whether to alert a driver of a vehicle to the presence of a traffic sign in the vehicle'"'"'s driving environment. An optical system on-board the vehicle detects the traffic sign and determine information related to the sign. Driving maneuvers carried out by the vehicle are monitored to determine driving situation information. The driving situation information and the traffic sign information are used to determine a probability that the sign is pertinent for the vehicle under the current driving conditions. If the probability is above a threshold, the driver is alerted to the traffic sign. The probability of the pertinence of the traffic sign may be further determined on the basis of lane-specific information such as vehicle position relative to a freeway exit ramp start or end, or performance of a lane change by the vehicle.

Claims

1. A method of determining whether to alert a driver of a vehicle to a speed limit sign adjacent to a roadway comprising:

operating an optical system on-board the vehicle to a) identify a start and an end of an exit ramp adjacent to the roadway, and b) detect a speed limit sign-;

monitoring driving maneuvers carried out by the vehicle to determine driving situation information;

determining, based on a position of the sign relative to at least one of the start and the end of the exit ramp, whether the sign applies only to the exit ramp;

using the driving situation information to determine whether the vehicle is turning off onto the exit ramp; and

suppressing a driver alert related to the speed limit sign if it is determined that a) the sign applies only to the exit ramp and b) the vehicle is not turning off onto the exit ramp.

2. The method of claim 1 wherein the driving situation information comprises at least one of a driving speed, a yaw rate, a steering wheel angle, a status of a vehicle navigation system, and a distance travelled by the vehicle.

3. The method of claim 1 wherein the determination whether the vehicle is turning off onto the exit ramp is related to performance of a lane change by the vehicle.

4. The method of claim 1 wherein the determination whether the vehicle is turning off onto the exit ramp is related to operation of a turn signal by the driver.

5. Apparatus for determining whether presence of a traffic sign is to be communicated to a driver of a vehicle comprising:

a camera system a) identifying an exit ramp start (ERS) and an exit ramp end (ERE) adjacent to a roadway on which the vehicle is travelling, and b) detecting the traffic sign and generating traffic sign information;

a vehicle system generating driving situation information; and

a recognition module operative to;

receive the traffic sign information from the camera, receive the driving situation information from the vehicle system, determine therefrom that a) based on a position of the traffic sign relative to at least one of the ERS and the ERE that the traffic sign applies only to the exit ramp and b) that the vehicle is turning off onto the exit ramp, and communicate presence of the traffic sign to the driver only upon the determinations a) and b) above.

6. The apparatus of claim 5 wherein the camera system further serves as part of a lane keeping system.

7. The apparatus of claim 5 wherein the sign information comprises at least one of a type of sign, a limit value prescribed by the sign, a position of the sign, and a restriction of the sign defined by an additional sign.

8. The apparatus of claim 5 wherein the driving situation information comprises at least one of a driving speed, a yaw rate, a steering wheel angle, a status of a vehicle navigation system, and a distance travelled by the vehicle.

9. The apparatus of claim 5 wherein the determination that the vehicle is turning off onto the exit ramp is based at least in part on performance of a lane change by the vehicle.

10. The apparatus of claim 5 wherein the determination that the vehicle is turning off onto the exit ramp is based at least in part on operation of a turn signal by the driver.

11. A method comprising:

operating an optical system on-board a vehicle to detect;

a) an exit ramp having a start and an end spaced from one another by a distance, and b) a speed limit sign and a position of the sign relative to the exit ramp;

determining driving situation information of the vehicle;

operating an traffic sign recognition module to determine that a) based on the position of the sign relative to the exit ramp the sign applies only to the exit ramp, and b) based on the driving situation information the vehicle is not turning off onto the exit ramp; and

if the driving situation information indicates the vehicle is not turning off onto the exit ramp, suppressing communication of presence of the sign to a vehicle driver.

12. The method of claim 11 wherein the driving situation information comprises at least one of a driving speed, a yaw rate, a steering wheel angle, a status of a vehicle navigation system, and a distance travelled by the vehicle.

13. The method of claim 11 further comprising:

operating the optical system to detect an additional traffic sign, and wherein the determination that the sign applies only to the exit ramp is further based upon a restriction of the speed limit sign defined by the additional sign.