Method and system for handling misclassification of speed signs

• US 10,657,394 B2
• Filed: 07/12/2018
• Issued: 05/19/2020
• Est. Priority Date: 07/12/2018
• Status: Active Grant

• Current Assignee: HERE Global B.V. (Nokia Corporation)
• Original Assignee: HERE Global B.V. (Nokia Corporation)
• Inventors: Stenneth, Leon
• Primary Examiner(s): Lu, Tom Y
• Application Number:
  US16/034,200
• Publication Number:
  US 20200019798A1
• Time in Patent Office: 677 Days
• CPC Class Codes: B60W 2554/804 Relative longitudinal speed
• CPC Class Codes: B60W 2555/60 Traffic rules, e.g. speed limits or right of way
• CPC Class Codes: B60W 2556/20 Data confidence level
• CPC Class Codes: B60W 50/14 Means for informing the driver, warning the driver or prompting a driver intervention
• CPC Class Codes: G06F 17/18 for evaluating statistical data , e.g. average values, frequency distributions, probability functions, regression analysis forecasting specially adapted for a specific administrative, business or logistic context G06Q10/04
• CPC Class Codes: G06T 1/0007 Image acquisition
• CPC Class Codes: G06T 2207/30256 Lane; Road marking
• CPC Class Codes: G06V 10/764 using classification, e.g. of video objects
• CPC Class Codes: G06V 20/582 of traffic signs
• CPC Class Codes: G06V 2201/08 Detecting or categorising vehicles

Abstract

A method, system, and computer program product is provided, for example, for assisting a user of the vehicle in following a prescribed speed limit while travelling in the vehicle. The method comprises providing a speed limit related recommendation to the user of the vehicle. The method further comprises receiving an image data representing a posted sign, in a vicinity of the vehicle, the image data being detected by one or more image capturing devices. Additionally, the method comprises processing the image data received to determine an observed numerical value. The method further comprises calculating, by a processor, a sign reliability factor based on a function of at least the observed numerical value, a historic mean of one or more vehicle speeds at the time of sign observation and a standard deviation of the one or more vehicle speeds at the time of sign observation. Additionally, the method may include providing data for an indication of the speed limit to be followed by the vehicle.

Claims

1. A method for providing a speed limit related recommendation to a user of a vehicle, the method comprising:

receiving an image data representing a posted sign, in a vicinity of the vehicle, the image data being detected by one or more image capturing devices;

processing the image data received to determine an observed numerical value;

calculating, by a processor, a sign reliability factor based on a function of at least the observed numerical value, a historic mean of one or more vehicle speeds at the time of sign observation and a standard deviation of the one or more vehicle speeds at the time of sign observation; and

providing data for an indication of a speed limit to be followed by the vehicle, on a user interface, based on the sign reliability factor of the observed numerical value being above or below a pre-defined threshold.

2. The method of claim 1, wherein the data for the indicated speed limit to be followed by the vehicle is the data for observed numerical value based on determining that the sign reliability factor of the observed numerical value is above the pre-defined threshold.

3. The method of claim 1, wherein the data for the indicated speed limit to be followed by the vehicle is a data for a speed limit available on a mapping database based on determining that the sign reliability factor of the observed numerical value is below the pre-defined threshold.

4. The method of claim 1, wherein calculating the sign reliability factor further comprises using a quality parameter based on a type of the vehicle.

5. The method of claim 1, wherein calculating the sign reliability factor further comprises using a weightage factor based on absolute z-value of the one or more vehicle speeds at the time of sign observation.

6. The method of claim 1, further comprising updating a speed limit available on a mapping database with the observed numerical value based on determining that the sign reliability factor of the observed numerical value is above the pre-defined threshold.

7. The method of claim 1, further comprising providing other data for determining a validation status for the posted sign based on the sign reliability factor of the observed numerical value being above or below the pre-defined threshold.

8. A navigation system comprising:

a user interface to provide a speed limit related recommendation to a user of a vehicle;

at least one processor; and

at least one non-transitory memory including computer program code instructions, the computer program code instructions configured to, when executed, cause the system to at least;

receive an image data representing a posted sign, in a vicinity of the vehicle, the image data being detected by one or more image capturing devices;

process the image data received to determine an observed numerical value;

calculate, using the processor, a sign reliability factor based on a function of at least the observed numerical value, a historic mean of one or more vehicle speeds at the time of sign observation and a standard deviation of the one or more vehicle speeds at the time of sign observation; and

provide data to display on the user interface, an indication of the speed limit to be followed by the vehicle, based on the sign reliability factor of the observed numerical value being above or below a pre-defined threshold.

9. The navigation system of claim 8, wherein the data for the indicated speed limit to be followed by the vehicle is the data for the observed numerical value based on determining that the sign reliability factor of the observed numerical value is above the pre-defined threshold.

10. The navigation system of claim 8, wherein the data for the indicated speed limit to be followed by the vehicle is a data for a speed limit available on a mapping database based on determining that the sign reliability factor of the observed numerical value is below the pre-defined threshold.

11. The navigation system of claim 8, wherein calculating the sign reliability factor further comprises using a quality parameter based on a type of the vehicle.

12. The navigation system of claim 8, wherein calculating the sign reliability factor further comprises using a weightage factor based on absolute z-value of the one or more vehicle speeds at the time of sign observation.

13. The navigation system of claim 8, wherein a speed limit available on a mapping database is updated with the observed numerical value based on determining that the sign reliability factor of the observed numerical value is above the pre-defined threshold.

14. The navigation system of claim 8, wherein the system is further caused to provide other data for determining a validation status for the posted sign based on the sign reliability factor of the observed numerical value being above or below the pre-defined threshold.

15. A computer program product comprising at least one non-transitory computer-readable storage medium having computer-executable program code instructions stored therein, the computer-executable program code instructions comprising program code instructions to:

receive an image data representing a posted sign, in a vicinity of the vehicle, the image data being detected by one or more image capturing devices;

process the image data received to determine an observed numerical value;

calculate, using a processor, a sign reliability factor based on a function of at least the observed numerical value, a historic mean of one or more vehicle speeds at the time of sign observation and a standard deviation of the one or more vehicle speeds at the time of sign observation; and

provide data for an indication of the speed limit to be followed by the vehicle, based on the sign reliability factor of the observed numerical value being above or below a pre-defined threshold.

16. The computer program product of claim 15, wherein the data for the indicated speed limit to be followed by the vehicle is the data for the observed numerical value based on determining the sign reliability factor of the observed numerical value is above the pre-defined threshold.

17. The computer program product of claim 15, wherein the data for the indicated speed limit to be followed by the vehicle is a data for a speed limit available on a mapping database based on determining that the sign reliability factor of the observed numerical value is below the pre-defined threshold.

18. The computer program product of claim 15, wherein calculating the sign reliability factor further comprises using a quality parameter based on a type of the vehicle.

19. The computer program product of claim 15, wherein calculating the sign reliability factor further comprises using a weightage factor based on absolute z-value of the one or more vehicle speeds at the time of sign observation.

20. The computer program product of claim 15 comprising further instructions to update a speed limit available on a mapping database with the observed numerical value based on determining that the sign reliability factor of the observed numerical value is above the pre-defined threshold.