DETERMINING A PATROL PATH

• US 20130325336A1
• Filed: 05/16/2013
• Published: 12/05/2013
• Est. Priority Date: 05/30/2012
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Dong, Wei Shan, Duan, Ning, Li, Li, Sun, Wei, Wang, Zhi Hu, Fellows, Ronald, Zhou, Chang Jin
• Granted Patent: US 9,285,232 B2
• Time in Patent Office: Days
• US Class Current: 701/527
• CPC Class Codes: G01C 21/3453 Special cost functions, i.e. other than distance or default speed limit of road segments
• CPC Class Codes: G01C 21/3461 Preferred or disfavoured areas, e.g. dangerous zones, toll or emission zones, intersections, manoeuvre types, segments such as motorways, toll roads, ferries

Abstract

A method of determining a path comprises obtaining a path in a road net, the road net comprising a plurality of nodes; calculating, with a processing device, an event displacement probability within coverage of the path, wherein the event displacement probability is used to describe a possibility of displacement of an event that could have occurred within the coverage of the path, to outside the coverage of the path to occur; and changing the path based on the event displacement probability.

Claims

1. A method of determining a path, the method comprising:

obtaining a path in a road net, the road net comprising a plurality of nodes;

calculating, with a processing device, an event displacement probability within coverage of the path, wherein the event displacement probability is used to describe a possibility of displacement of an event that could have occurred within the coverage of the path, to outside the coverage of the path to occur; and

changing the path based on the event displacement probability.

2. The method according to claim 1, wherein the coverage of the path comprises at least one of:

a range reachable by eyesight when one is progressing along the path;

a range reachable by sound produced when one is progressing along the path;

a maximum range enclosed by all points having a straight-line distance A with each node in the path;

a maximum range enclosed by all points having a path distance B with each node in the path, wherein the path distance is a length of progressing along a road in the road net.

3. The method according to claim 2, wherein an event displacement probability within coverage of the path is used to describe a possibility of displacement of an event that could have occurred within the coverage of the path, to an extended area and occur outside the coverage of the path, wherein the extended area comprises one of:

a maximum range enclosed by all points having a straight-line distance C with a border of the coverage of the path;

a maximum range enclosed by all points having a path distance D with a border of the coverage of the path;

a part which is the maximum range enclosed by all points having a straight-line distance C with a border of the coverage of the path subtracted by the coverage of the path;

a part which is the maximum range enclosed by all points having a path distance D with a border of the coverage of the path subtracted by the coverage of the path.

4. The method according to claim 3, the calculating an event displacement probability within coverage of the path comprising:

calculating an event displacement probability within coverage of the path based on historical data of an event occurring probability within the coverage of the path during a period, and historical data of an event occurring probability within the extended area during the same period.

5. The method according to claim 4, wherein the calculating an event displacement probability within coverage of the path further comprises:

taking historical data of an area other than the extended area during the same period as a basis for the calculating.

6. The method according to claim 1, wherein the method further comprises calculating event occurring probabilities between adjacent nodes in the road net, and the changing the path based on the event displacement probability comprises changing, based on the event displacement probability, an event occurring probability between at least one node within the coverage of the path and nodes adjacent to the at least one node, and obtaining a new path based on the changed event occurring probability.

7. The method according to claim 1, wherein the method further comprises:

obtaining X paths in the road net, an end node of every path being a node whose path distance from a start node is closest to E, and E being a set distance;

calculating event occurring probabilities between adjacent nodes in the road net;

obtaining Y paths having the highest event occurring probability in the X paths based on the event occurring probabilities between adjacent nodes in the road net;

calculating a probability for a node to present on the Y paths; and

the changing the path based on the event displacement probability comprises changing, based on the event displacement probability, a probability for at least one node within the coverage of the path to present on the Y paths, and obtaining a new path based on the probability for the changed node to present on the Y paths.

8. The method according to claim 1, wherein the method further comprises:

obtaining P paths in the road net, an end node of every path being a node whose path distance from a start node is closest to F, and F being a set distance;

calculating event occurring probabilities between adjacent nodes in the road net;

obtaining Q paths having the highest event occurring probability in the P paths based on the event occurring probabilities between adjacent nodes in the road net;

calculating a probability for a node to present on the Q paths;

generating a transformation matrix based on a probability for a node to present on the Q paths, wherein if a first node is adjacent to a second node, at least one value corresponding to the second node in the transformation matrix is a ratio of the probability for the second node to present on the Q paths to a sum of probabilities for each node adjacent to the first node to present on the Q paths; and

wherein the changing the path based on the event displacement probability comprises updating, based on the event displacement probability, at least one value corresponding to at least one node within the coverage of the path in the transformation matrix, and obtaining a new path based on the updated transformation matrix.

9. A method of indicating a patrol path, the method comprising:

receiving a request which comprises information indicating a start point of the patrol path;

obtaining a path changed based on an event displacement probability according to the method of claim 1, wherein the path changed based on an event displacement probability takes the indicated start point of the patrol path as a start point; and

sending an indication of a patrol path based on the path changed based on the event displacement probability.

10. The method according to claim 9, wherein:

the request further comprises information indicating a direction of the patrol path; and

the path changed based on the event displacement probability takes the indicated start point of the patrol path as a start point and is along the indicated direction of the patrol path.

11-19. -19. (canceled)