Probe based variable speed sign value

• US 10,109,184 B2
• Filed: 10/08/2014
• Issued: 10/23/2018
• Est. Priority Date: 10/08/2014
• Status: Active Grant

• Current Assignee: HERE Global B.V. (HERE Holding Corporation)
• Original Assignee: HERE Global B.V. (HERE Holding Corporation)
• Inventors: Fowe, James Adeyemi, Capota, Catalin, Stenneth, Leon Oliver
• Primary Examiner(s): Shaawat, Mussa A
• Assistant Examiner(s): Kim, Kyung J
• Application Number:
  US14/509,487
• Publication Number:
  US 20160104376A1
• Time in Patent Office: 1,476 Days
• Field of Search: None
• CPC Class Codes: G08G 1/0112 from the vehicle, e.g. floating car data [FCD]
• CPC Class Codes: G08G 1/0116 from roadside infrastructure, e.g. beacons
• CPC Class Codes: G08G 1/0129 for creating historical data or processing based on historical data
• CPC Class Codes: G08G 1/0141 for traffic information dissemination
• CPC Class Codes: G08G 1/052 with provision for determining speed or overspeed speed measuring in general G01P
• 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
• CPC Class Codes: G08G 1/096716 where the received information does not generate an automatic action on the vehicle control
• CPC Class Codes: G08G 1/096741 where the source of the transmitted information selects which information to transmit to each vehicle
• CPC Class Codes: G08G 1/096775 where the origin of the information is a central station

Abstract

Systems, methods, and apparatuses are disclosed for predicting or estimating the value of a variable speed sign (VSS). A variable speed sign is identified. Probe data is collected at one or more vehicles in proximity to the variable speed sign. The speeds of the vehicles are included in or derived from the probe data. A statistical analysis is performed on the probe data. A speed limit value for the variable speed sign is determined based on the statistical analysis.

Claims

1. A method comprising:

identifying a variable speed sign;

receiving probe data collected at a plurality of vehicles in proximity to the variable speed sign, wherein the probe data is collected by a plurality of mobile devices and includes speeds of the plurality of vehicles;

performing a statistical analysis on the probe data;

determining, using the processor, an estimated speed limit value for the variable speed sign based on the statistical analysis; and

reporting the estimated speed limit value to at least one mobile device or at least one vehicle, wherein the estimated speed limit value is used by the at least one mobile device or the at least one vehicle to control a speed of the at least one vehicle by increasing or decreasing throttle or braking force of the at least one vehicle.

2. The method of claim 1, further comprising:

selecting a predetermined number of road links downstream of the variable speed sign, wherein the probe data is associated with the predetermined number of road links.

3. The method of claim 2, further comprising:

determining the predetermined number based on a geographical region.

4. The method of claim 1, further comprising:

determining a medoid factor (K) for the statistical analysis, wherein the statistical analysis includes K medoid clustering.

5. The method of claim 4, wherein the medoid factor is based on a standard deviation of at least a subset of the probe data.

6. The method of claim 4, further comprising:

comparing a size of a first speed cluster from the K medoid clustering to a size of a second speed cluster from the K medoid clustering; and

when the size of the first speed cluster is less than the size of the second speed cluster, removing the first speed cluster as possible outliers,

wherein the first speed cluster is higher than the second speed cluster.

7. The method of claim 4, further comprising:

identifying a plurality of centroids from the K medoid clustering; and

storing the plurality of centroids as a set of possible speed limit values.

8. The method of claim 7, wherein the probe data collected at the plurality of vehicles includes recent probe data and the statistical analysis is a first statistical analysis, the method further comprising:

performing a second statistical analysis on the recent probe data; and

selecting the speed limit value for the variable speed sign from the set of possible speed limit values in response to the second statistical analysis.

9. The method of claim 8, wherein performing the second statistical analysis comprises:

performing K medoid clustering on the recent probe data;

identifying a winning medoid from the K medoid clustering, and wherein selecting the speed limit value includes;

performing a nearest neighbor search for the winning medoid from the set of possible speed limit values.

10. The method of claim 1, wherein the estimated speed limit value is used by the at least one mobile device or the at least one vehicle to select a route for the at least one vehicle.

11. An apparatus comprising:

at least one processor; and

at least one memory including computer program code for one or more programs;

the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least perform;

identifying a variable speed sign;

receiving probe data collected from a plurality of vehicles downstream of the variable speed sign, wherein the probe data includes speeds of the plurality of vehicles and locations of the plurality of vehicles;

performing a statistical analysis on the probe data;

selecting, using the processor, an estimated speed limit value for the variable speed sign based on the statistical analysis; and

reporting the estimated speed limit value to a mobile device or a vehicle associated with the mobile device, wherein the estimated speed limit value is used by the mobile device or the vehicle associated with the mobile device to autonomously control a speed of the vehicle associated with the mobile device.

12. The apparatus of claim 11, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least perform:

selecting a medoid factor (K) for the statistical analysis based on a standard deviation of at least a subset of the probe data, wherein the statistical analysis includes K medoid clustering.

13. The apparatus of claim 12, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least perform:

comparing a size of a first speed cluster from the K medoid clustering to a size of a second speed cluster from the K medoid clustering;

in response to the size of the first speed cluster being less than the size of the second speed cluster, removing the first speed cluster as possible outliers.

14. The apparatus of claim 12, the at least one memory and the computer program code configured to, with the at least one processor, cause the apparatus to at least perform:

identifying a plurality of centroids from the K medoid clustering; and

storing the plurality of centroids as a set of possible speed limit values.

15. The apparatus of claim 12, wherein the statistical analysis comprises a first statistical analysis on historical probe data resulting in a set of possible speed limit values and a second statistical analysis on recent probe data to select one of the set of possible speed limit values.

16. The apparatus of claim 15, wherein the estimated speed limit value is selected from the set of possible speed limit values as a nearest neighbor of a centroid from the second statistical analysis.

17. The apparatus of claim 15, wherein the first statistical analysis includes K medoid clustering on the historical probe data and the second statistical analysis includes K medoid clustering on the recent probe data.

18. The apparatus of claim 11, wherein autonomously controlling the speed of the vehicle associated with the mobile device comprises adjusting a throttle or a brake force, wherein the vehicle associated with the mobile device is an autonomous vehicle or a highly assisted vehicle.

19. The apparatus of claim 11, wherein the estimated speed limit value is used in selection of a route.

20. A non-transitory computer readable medium including instructions that when executed on a computer are operable to:

collect probe data including geographic locations of a plurality of vehicles;

send the probe data including geographic locations to an external device, wherein a variable speed sign is identified from the geographic locations and a vehicle speed is derived from the probe data;

receive an estimated speed limit value for the variable speed sign based on a statistical analysis of the probe data, wherein the statistical analysis includes clustering; and

provide the estimated speed limit value to a mobile device or a vehicle associated with the mobile device for controlling a speed of the vehicle, wherein the estimated speed limit value is used by the mobile device or the vehicle to autonomously control the speed of the vehicle associated with the mobile device by increasing or decreasing a throttle or braking force of the vehicle.