Process for the automatic determination of speed limitations on a road and an associated system

• US 8,428,307 B2
• Filed: 07/18/2008
• Issued: 04/23/2013
• Est. Priority Date: 07/20/2007
• Status: Active Grant

• Current Assignee: Valeo Vision (Valeo SE)
• Original Assignee: Valeo Vision (Valeo SE)
• Inventors: Bradai, Benazouz, Lauffenburger, Jean-Philippe, Basset, Michel, Herbin-Sahler, Anne
• Primary Examiner(s): Mehta, Bhavesh
• Assistant Examiner(s): ANSARI, TAHMINA N
• Application Number:
  US12/175,565
• Publication Number:
  US 20090041304A1
• Time in Patent Office: 1,740 Days
• Field of Search: None
• US Class Current: 382/104
• 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 1/09626 where the origin of the information is within the own vehicle, e.g. a local storage device, digital map

Abstract

An automatic process is provided for automatically determining a current speed limitation on a road being used by a motor vehicle, in which by means of a first system, making use in particular of a GPS aerial and cartographical details, a first set of information is established, in which at least one likely speed limitation is associated with a confidence index; by means of a second system, involving the use of a camera and image processing applications capable of identifying roadside speed limitation panels, a second set of information is established comprising at least one probable speed limitation, wherein the basis of the first and second sets of information, the current speed limitation is determined along the road in question.

Claims

1. A process for the automatic determination of a current speed limitation on a road that is being used, or about to be used, by a motor vehicle, comprising the following steps:

establishing, by means of a first system, known as the navigation system, which involves notably a data receiver from a geographical positioning system together with cartographical data, a likely speed limitation associated with a first confidence index;

generating a first set of information comprising at least the likely speed limitation and the first confidence index;

establishing, by means of a second system, known as the image processing system, which involves notably the use of a camera and image processing applications capable of identifying and interpreting speed limitation panels arranged in the vicinity of the road, a probable speed limitation associated with a second confidence index;

generating a second set of information comprising at least the probable speed limitation and the second confidence index; and

determining the current speed limitation on the road in question, on the basis of the first set of information and the second set of information and taking into consideration the first confidence index and the second confidence index;

wherein said first confidence index is calculated using a first plurality of criteria of information that is weighted in relation to a confidence of their associated information.

2. The process according to claim 1, wherein the first set of information is completed by a set of additional likely speed limitations.

3. The process according to claim 1, wherein the likely speed limitation and each additional likely speed limitation are associated with a weighting coefficient, known as a mass of belief, determined on the basis of at least one of the following parameters:

the first confidence index;

an index for the consistency between the likely speed limitation and the characteristics of the road provided by navigation system.

4. The process according to claim 2, wherein the additional likely speed limitations are the two statutory speed limitations immediately preceding and following the likely speed limitation.

5. The process according to claim 1, wherein the second set of information is completed by a set of additional probable speed limitations.

6. The process according to claim 1, wherein the probable speed limitation and each additional probable speed limitation are associated with a weighting coefficient, known as a mass of belief, determined on the basis of at least one of the following parameters:

the second confidence index;

an index of possible confusion between the figures constituting the established probable speed limitation and other figures.

9. The process according to claim 1, wherein said process comprises an additional step consisting in only using the determined current speed limitation if a third confidence index is greater than a third threshold value.

10. The process according to claim 1, wherein the first confidence index is calculated on the basis of one or more parameters from a first set of parameters made up of the following parameters:

accuracy of the geographical positioning system;

level of information on the road;

functional class of the road;

type of road;

surroundings of the vehicle;

selection of a driving mode by the driver and the level of conformity between a pre-determined itinerary and information provided by sensors fitted to the vehicle;

accuracy of the digitization of the cartography;

date on which the cartography was last updated.

11. The process according to claim 10, wherein the first confidence index is calculated by carrying out a weighted average of values assigned to the following parameters, the parameters being associated with weighting coefficients obtained from a learning phase:

accuracy of the geographical positioning system;

level of information on the road;

functional class of the road;

type of road;

surroundings of the vehicle;

selection of a driving mode by the driver and the level of conformity between a pre-determined itinerary and information provided by sensors fitted to the vehicle.

7. A process for the automatic determination of a current speed limitation on a road that is being used, or about to be used, by a motor vehicle, comprising the following steps:

establishing, by means of a first system, known as the navigation system, which involves notably a data receiver from a geographical positioning system together with cartographical data, a likely speed limitation associated with a first confidence index;

constituting a first set of information comprising at least the likely speed limitation and the first confidence index;

establishing, by means of a second system, known as the image processing system, which involves notably the use of a camera and image processing applications capable of identifying and interpreting speed limitation panels arranged in the vicinity of the road, a probable speed limitation associated with a second confidence index;

constituting a second set of information comprising at least the probable speed limitation and the second confidence index; and

determining the current speed limitation on the road in question, on the basis of the first set of information and the second set information and taking into consideration the first confidence index and the second confidence index;

wherein the set of additional probable speed limitations are statutory speed limitations for which an index for the possible confusion between the figures constituting the established probable speed limitation and the figures for the set of additional probable speed limitation is greater than a threshold value, known as the critical threshold value.

8. A process for the automatic determination of a current speed limitation on a road that is being used, or about to be used, by a motor vehicle, comprising the following steps:

establishing, by means of a first system, known as the navigation system, which involves notably a data receiver from a geographical positioning system together with cartographical data, a likely speed limitation associated with a first confidence index;

constituting a first set of information comprising at least the likely speed limitation and the first confidence index;

establishing, by means of a second system, known as the image processing system, which involves notably the use of a camera and image processing applications capable of identifying and interpreting speed limitation panels arranged in the vicinity of the road, a probable speed limitation associated with a second confidence index;

constituting a second set of information comprising at least the probable speed limitation and the second confidence index; and

determining the current speed limitation on the road in question, on the basis of the first set of information and the second set of information and taking into consideration the first confidence index and the second confidence index;

wherein the determined current speed limitation is associated with a third confidence index, calculated at least on the basis of the first confidence index and the second confidence index.

12. A process for the automatic determination of a current speed limitation on a road that is being used, or about to be used, by a motor vehicle, comprising the following steps:

establishing, by means of a first system, known as the navigation system, which involves notably a data receiver from a geographical positioning system together with cartographical data, a likely speed limitation associated with a first confidence index;

constituting a first set of information comprising at least the likely speed limitation and the first confidence index;

establishing, by means of a second system, known as the image processing system, which involves notably the use of a camera and image processing applications capable of identifying and interpreting speed limitation panels arranged in the vicinity of the road, a probable speed limitation associated with a second confidence index;

constituting a second set of information comprising at least the probable speed limitation and the second confidence index; and

determining the current speed limitation on the road in question, on the basis of the first set of information and the second set of information and taking into consideration the first confidence index and the second confidence index;

wherein the second confidence index is calculated on the basis of one or more parameters, from a second set of parameters relating to one or more images obtained by the camera, from the following;

index of the consistency of the identification of speed limitation panels from one image to the next one;

measurement of the texture of the image in question,

shadow factor of the image in question,

vertical gradient of the reduction of the light,

symmetry index of the image in question.

13. The process according to claim 12, wherein the second confidence index is calculated by carrying out a weighted average of the values assigned to all of the parameters of the second set of parameters, these parameters being associated with weighting coefficients resulting from a learning phase.

14. A process for the automatic determination of a current speed limitation on a road that is being used, or about to be used, by a motor vehicle, comprising the following steps:

establishing, by means of a first system, known as the navigation system, which involves notably a data receiver from a geographical positioning system together with cartographical data, a likely speed limitation associated with a first confidence index;

constituting a first set of information comprising at least the likely speed limitation and the first confidence index;

establishing, by means of a second system, known as the image processing system, which involves notably the use of a camera and image processing applications capable of identifying and interpreting speed limitation panels arranged in the vicinity of the road, a probable speed limitation associated with a second confidence index;

constituting a second set of information comprising at least the probable speed limitation and the second confidence index; and

determining the current seed limitation on the road in question, on the basis of the first set of information and the second set of information and taking into consideration the first confidence index and the second confidence index;

wherein said process comprises additional steps, consisting in;

comparing the first confidence index with a first threshold value and the second confidence index with a second threshold value;

when determining the current speed limitation, considering only the set or sets of information, from the first set of information and the second set of information, the confidence index of which is greater than the threshold value to which it is compared.

15. A process for the automatic determination of a current speed limitation on a road that is being used, or about to be used, by a motor vehicle, comprising the following steps:

establishing, by means of a first system, known as the navigation system, which involves notably a data receiver from a geographical positioning system together with cartographical data, a likely speed limitation associated with a first confidence index;

constituting a first set of information comprising at least the likely speed limitation and the first confidence index;

establishing, by means of a second system, known as the image processing system, which involves notably the use of a camera and image processing applications capable of identifying and interpreting speed limitation panels arranged in the vicinity of the road, a probable speed limitation associated with a second confidence index;

constituting a second set of information comprising at least the probable speed limitation and the second confidence index; and

determining the current speed limitation on the road in question on the basis of the first set of information and the second set of information and taking into consideration the first confidence index and the second confidence index;

wherein the step for the determination of the current speed limitation involves the use of a Dempster-Shafer equation.

16. A system for automatic determining a current speed limitation for a road being driven on, or about to be driven on, by a motor vehicle, wherein said system comprises:

a first system, known as the navigation system, involving notably a geographical positioning system and cartographical data in order to establish a likely speed limitation associated with a first confidence index and to constitute a first set of information comprising at least the likely speed limitation and the first confidence index;

a second system, known as the image processing system, involving notably the use of a camera and image processing applications, capable of identifying and interpreting speed limitation panels arranged in the vicinity of the road, in order to establish a probable speed limitation associated with a second confidence index and in order to constitute a second set of information comprising at least the probable speed limitation and the second confidence index;

means for associating said first confidence index to said first set of information and said second confidence index to said second set of information and for processing information in order to determine, from said first set of information and said second set of information, said current speed limitation in force on the road in question in response to an evaluation of both said first set of information and said first confidence index and said second set of information and said second confidence index.

17. The system according to claim 16, wherein said system comprises means for restitution of the determined current speed limitation.

18. A system for automatic determining a current speed limitation for a road being driven on, or about to be driven on, by a motor vehicle, said system comprising:

a geographical positioning system for establishing a likely speed limitation associated with a first confidence index;

a camera and image processing system, capable of identifying and interpreting speed limitation panels arranged in the vicinity of the road in order to establish a probable speed limitation associated with a second confidence index; and

a data fusion system for receiving a first set of information and a second set of information and for associating said first confidence index to said first set of information and said second confidence index to said second set of information and for determining said current speed limitation in force on the road in question in response to an evaluation of both said first set of information and said first confidence index and said second set of information and said second confidence index.

19. The system according to claim 18, wherein said system comprises means for restitution of the determined current speed limitation.

20. The system according to claim 18, wherein said data fusion system displays said likely speed limitation if said first confidence index is greater than said second confidence index or displays said probable speed limitation if said second confidence index exceeds said first confidence index.