Method and apparatus for traffic management

Patent metadata

Field	Value
Publication number	US-9424744-B2
Application number	US-201013505165-A
Country	US
Kind code	B2
Filing date	Oct 18, 2010
Priority date	Oct 30, 2009
Publication date	Aug 23, 2016
Grant date	Aug 23, 2016

Abstract

A method for determining travel time of a vehicle on a road, wherein the vehicle is operable within a mobile communication network, comprising: collecting historical communication events of a mobile user in order to obtain travel samples, wherein the historical communication events indicate when the mobile user travelled along a monitored road; determining a cell handover sequence from the historical communication events; determining from the cell handover sequence, one of more road segments of the monitored road; determining the travel time of the one or more road segments according to the travel time samples; selecting, for an undetermined road segment of the monitored road for which the real-time travel time is not determined from the collected historical communication events, a candidate mobile user that is most likely to appear on the undetermined road segment; actively positioning the candidate mobile user to obtain positioning information; and returning to the step of collecting communication events of a mobile user currently on a monitored road with the active positioning as one communication event for the candidate mobile user, to determine the real-time travel time of the undetermined road segment.

First claim

The invention claimed is:

1. A method for determining travel time of a vehicle on a road, wherein the vehicle is operable within a mobile communication network, comprising:
collecting historical communication events of a mobile user in order to obtain travel samples, wherein the historical communication events indicate when the mobile user travelled along a monitored road;
determining a cell handover sequence from the historical communication events;
determining from the cell handover sequence, one of more road segments of the monitored road;
determining the travel time of the one or more road segments according to the travel time samples;
selecting, for an undetermined road segment of the monitored road for which the real-time travel time is not determined from the collected historical communication events, a candidate mobile user that is most likely to appear on the undetermined road segment;
calculating a travel probability of each mobile user to pass the undetermined road segment at a specified time, said candidate mobile user being selected based on said calculated travel probability, the travel probability of a mobile user being calculated as a function of an estimated speed and a speed vector of the mobile user on the monitored road, said estimated speed calculated by:
computing a minimum travel speed and a maximum travel speed of the each mobile user, the minimum and maximum travel speed of the each mobile user computed as a function of: a distance from a position of a cell to which the each mobile user belongs at a current time to a start point of the undetermined road segment, a coverage radius of the cell, a length of the undetermined road segment, and the current time;

actively positioning the candidate mobile user to obtain positioning information; and
returning to the step of collecting communication events of a mobile user currently on a monitored road with the active positioning as one communication event for the candidate mobile user, to determine the real-time travel time of the undetermined road segment.

2. The method of claim 1 , wherein the step of collecting historical communication related to a mobile user currently on a monitored road to obtain travel time samples further comprises:
collecting two continuous communication events related to the same mobile user within a predetermined time period; and
recording positions of cells in which the two communication events took place and a time difference between the two communication events as the travel time sample.

3. The method of claim 2 , wherein the step of determining the real-time travel time of a road segment in the monitored road according to the travel time samples further comprises:
determining, for each of the travel time samples, whether the positions of two cells in the travel time sample are the same, and determining that the travel time sample is a valid travel time sample when the positions of these two cells are different;
selecting, from the valid travel time samples, an unambiguous sample that can uniquely determine the real-time travel time of a certain road segment;
identifying the certain road segment with the unambiguous sample;
comparing, for an ambiguous sample in the valid travel time samples, the time difference in the ambiguous sample with a sum of the real-time travel time of the respective constituent road segments of each of the possible road segments corresponding to the ambiguous sample to select the possible road segment that is nearest in time, wherein for the constituent road segment for which the real-time travel time is not determined, a baseline travel time of the constituent road segment is used to replace its real-time travel time; and
identifying the possible road segment that is nearest in time with the ambiguous sample.

4. The method of claim 3 , wherein the step of determining the real-time travel time of corresponding road segment in the monitored road according to the travel time samples further comprises:
determining whether these two cells are neighbouring cells when the positions of these two cells are different; and
determining that the travel time sample is valid when these two cells are not the neighbouring cells.

5. The method of claim 3 , wherein the step of determining the real-time travel time of corresponding road segment on the monitored road according to the travel time samples further comprises:
calculating arithmetic average value of unambiguous samples when a plurality of unambiguous samples exists for the same road segment; and
identifying the road segment with the arithmetic average value.

6. The method of claim 1 , wherein the step of selecting, for an undetermined road segment on the monitored road for which the real-time travel time is not determined, a candidate mobile user that is most likely to appear on the undetermined road segment comprises:
analyzing moving modes and speed vectors of the corresponding mobile users on the monitored road according to the valid travel time samples;
estimating, the travel speed of each corresponding mobile user passing the undetermined road segment from the current time to said specified time; and
selecting a certain number of mobile users with a large calculated travel probability as the candidate mobile user.

7. The method of claim 6 , wherein the step of estimating, for each of the corresponding mobile users, the travel speed at which the mobile user passes the undetermined road segment from current time to specified time comprises:
estimating the minimum travel speed of the mobile user according to

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 wherein E[d] represents the distance from the position of the cell to which the mobile user belongs at the current time to the start point of the undetermined road segment, R represents the coverage radius of the cell, K represents the length of the undetermined road segment, t represents the specified time, T represents the current time; and
estimating the maximum travel speed of the mobile user according to

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Assignees

• Shang Wei Xiong
• Wang Hua Yong
• Xiang Zhe
• Ying Chun
• Zhou Jin Z
• Zhu yan feng
• IBM

Inventors

• Shang Wei Xiong
• Wang Hua Yong
• Xiang Zhe
• Ying Chun
• Zhou Jin Z
• Zhu yan feng

Classifications

• G08G1/0141

  for traffic information dissemination · CPC title

• H04W4/027

  using movement velocity, acceleration information · CPC title

• H04W4/029

  Location-based management or tracking services · CPC title

• H04W4/026

  using orientation information, e.g. compass · CPC title

• G08G1/0104 Primary

  Measuring and analyzing of parameters relative to traffic conditions · CPC title