Utilizing determined optimized time windows for precomputing optimal path matrices to reduce computer resource usage

• US 10,354,529 B1
• Filed: 12/31/2018
• Issued: 07/16/2019
• Est. Priority Date: 08/02/2018
• Status: Active Grant

• Current Assignee: Salesforce.com, Inc.
• Original Assignee: MapAnything, Inc. (Salesforce.com, Inc.)
• Inventors: Stewart, John Brian, Weerapurage, Dinesh Premalal, Carnes, Timothy Alan, Groer, Christopher Sebastian, Gallege, Lahiru Sandakith Pileththuwasan, Lou, Chenlu
• Primary Examiner(s): Kiswanto, Nicholas
• Application Number:
  US16/236,644
• Time in Patent Office: 197 Days
• CPC Class Codes: G01C 21/3492 employing speed data or traffic data, e.g. real-time or historical traffic control systems for road vehicles involving transmission of navigation instructions to the vehicle G08G1/0968
• CPC Class Codes: G06F 17/11 for solving equations , e.g. nonlinear equations, general mathematical optimization problems optimization specially adapted for a specific administrative, business or logistic context G06Q10/04
• CPC Class Codes: G06F 17/16 Matrix or vector computation , e.g. matrix-matrix or matrix-vector multiplication, matrix factorization matrix transposition G06F7/78
• CPC Class Codes: G06Q 10/047 Optimisation of routes or paths, e.g. travelling salesman problem
• CPC Class Codes: G08G 1/096811 where the route is computed offboard
• CPC Class Codes: G08G 1/0969 having a display in the form of a map

Abstract

A method involves accelerating the electronic determination of high quality solutions to routing problems by utilizing determined optimized time windows for precomputing optimal path matrices to reduce computer resource usage. The use of traffic windows defined based on changes in rates of change of speeds for traffic on road segments allows for more rapid determination of a set of one or more high quality solutions as compared to requiring on-demand, in-process determination of a shortest path for a particular time during comparison of paths or routes performed as part of a process for determining high quality solutions to the routing problem.

Claims

1. A system configured to accelerate the electronic determination of optimized solutions to routing problems by utilizing determined optimized time windows for precomputing optimal path matrices to reduce computer resource usage, the system comprising:

(a) one or more data servers each including traffic data for road segments in one or more areas of a road network; and

(b) a server comprising one or more processors and one or more non-transitory computer readable media containing computer executable instructions executable by the one or more processors for performing a method comprising

(i) receiving, at the server, problem data for a routing problem comprising information for one or more locations involved in the routing problem;

(ii) electronically accessing, from the one or more data servers, traffic data for a first set of road segments in one or more areas of a road network encompassing the one or more locations, the traffic data comprising data for a travel metric for travel along the road segments at various times of day;

(iii) electronically calculating, based on the accessed traffic data, data for a best fit line representing a best fit for the accessed traffic data, the data for the best fit line including, for each of various respective times of day, a respective best fit value for the travel metric for that respective time of day;

(iv) electronically defining, based on the calculated data for the best fit line, a plurality of traffic windows each having a start time and an end time during a day, electronically defining the plurality of traffic windows comprising

(A) electronically determining a plurality of inflection points representing times of day at which a change in a rate of change of the best fit line exceeds a minimum threshold, and

(B) electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points, each inflection point representing an end time for one traffic window and a start time for another traffic window;

(v) electronically populating one or more optimal path matrices with travel value estimates for each defined traffic window by, for each respective defined traffic window, calculating, for each of one or more respective ordered pairs of locations involved in the routing problem, a respective travel value estimate for an optimal path for travel from a respective first location of the respective ordered pair of locations to a respective second location of the respective ordered pair of locations, such calculated respective travel value estimate being calculated based on road network data and traffic data for that respective defined traffic window;

(vi) electronically determining a set of one or more optimized solutions to the routing problem using a plurality of the calculated travel time values accessed from the one or more optimal path matrices; and

(vii) returning, from the server, data corresponding to the determined set of one or more optimized solutions to the routing problem;

(viii) wherein the use of traffic windows defined based on changes in rates of change of the travel metric for travel on road segments allows for more rapid determination of the set of one or more optimized solutions as compared to requiring on-demand, in-process determination of an optimal path for a particular time during comparison of paths or routes performed as part of a process for determining optimized solutions to the routing problem.

2. The system of claim 1, wherein electronically determining a plurality of inflection points representing times of day at which a change in a rate of change of the best fit line exceeds a minimum threshold comprises applying statistical methods to determine the plurality of inflection points.

3. The system of claim 1, wherein electronically determining a plurality of inflection points representing times of day at which a change in a rate of change of the best fit line exceeds a minimum threshold comprises calculating one or more second derivatives of the best fit line.

4. The system of claim 1, wherein electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points comprises automatically defining a start time for a first traffic window proximate a certain time of day.

5. The system of claim 1, wherein electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points comprises automatically defining a start time for a first traffic window proximate midnight.

6. The system of claim 1, wherein electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points comprises automatically defining an end time for a last traffic window proximate a certain time of day.

7. The system of claim 1, wherein electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points comprises automatically defining an end time for a last traffic window proximate midnight.

8. The system of claim 1, wherein electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points comprises defining a traffic window which overlaps from one day to a next day.

9. The system of claim 1, wherein electronically populating one or more optimal path matrices with travel time estimates for each defined traffic window comprises electronically populating a different optimal path matrix for each defined traffic window.

10. The system of claim 1, wherein electronically populating one or more optimal path matrices with travel time estimates for each defined traffic window comprises electronically populating a single optimal path matrix with travel time estimates for each defined traffic window.

11. The system of claim 1, wherein the travel metric comprises a speed metric.

12. The system of claim 1, wherein the travel metric comprises a travel time metric.

13. A system configured to accelerate the electronic determination of optimized solutions to routing problems by utilizing determined optimized time windows for precomputing optimal path matrices to reduce computer resource usage, the system comprising:

(a) one or more data servers each including traffic data for road segments in one or more areas of a road network; and

(b) a server comprising one or more processors and one or more non-transitory computer readable media containing computer executable instructions executable by the one or more processors for performing a method comprising

(i) receiving, at a server, problem data for a routing problem comprising information for one or more locations involved in the routing problem;

(ii) electronically accessing, from the one or more data servers, traffic data for a first set of road segments in one or more areas of a road network encompassing the one or more locations, the traffic data comprising data for a travel metric for travel along the road segments at various times of day;

(iii) electronically defining, based on the accessed traffic data for the first set of road segments, a plurality of traffic windows each having a start time and an end time during a day, electronically defining the plurality of traffic windows comprising

(A) electronically applying statistical methods to the accessed traffic data to determine a plurality of inflection points which represent times of day at which a change in a rate of change of the travel metric exceeds a minimum threshold, and

(B) electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points, each inflection point representing an end time for one traffic window and a start time for another traffic window;

(iv) electronically populating one or more optimal path matrices with travel value estimates for each defined traffic window by, for each respective defined traffic window, calculating, for each of one or more respective ordered pairs of locations involved in the routing problem, a respective travel value estimate for an optimal path for travel from a respective first location of the respective ordered pair of locations to a respective second location of the respective ordered pair of locations, such calculated respective travel value estimate being calculated based on road network data and traffic data for that respective defined traffic window;

(v) electronically determining a set of one or more optimized solutions to the routing problem using a plurality of the calculated travel time values accessed from the one or more optimal path matrices; and

(vi) returning, from the server, data corresponding to the determined set of one or more optimized solutions to the routing problem;

(vii) wherein the use of traffic windows defined based on changes in rates of change of the travel metric for travel on road segments allows for more rapid determination of the set of one or more optimized solutions as compared to requiring on-demand, in-process determination of an optimal path for a particular time during comparison of paths or routes performed as part of a process for determining optimized solutions to the routing problem.

14. The system of claim 13, wherein the travel metric comprises a speed metric.

15. The system of claim 13, wherein the travel metric comprises a travel time metric.

16. The system of claim 13, wherein electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points comprises automatically defining a start time for a first traffic window proximate a certain time of day.

17. The system of claim 13, wherein electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points comprises automatically defining a start time for a first traffic window proximate midnight.

18. The system of claim 13, wherein electronically defining a start time and an end time for each traffic window of the plurality of traffic windows based on the determined plurality of inflection points comprises defining a traffic window which overlaps from one day to a next day.

19. The system of claim 13, wherein electronically populating one or more optimal path matrices with travel time estimates for each defined traffic window comprises electronically populating a different optimal path matrix for each defined traffic window.

20. The system of claim 13, wherein electronically populating one or more optimal path matrices with travel time estimates for each defined traffic window comprises electronically populating a single optimal path matrix with travel time estimates for each defined traffic window.