Method and system for querying in a moving object database
View Patent ↗A database receives location information about a moving object. Using the destination of the object and an electronic map, the database finds a projected path for the moving object. From the projected path, the database computes a trajectory. The trajectory may be used to estimate past and future positions of the moving object. The moving object may send location updates to the database when its actual location differs from its anticipated location by more than an uncertainty threshold.
1. A method of querying trajectory data for a moving object, the method comprising:
receiving from a user at least one query input parameter;
accessing a trajectory for a moving object, wherein the trajectory defines permissible spatial and temporal uncertainties in actual locations of the moving object relative to expected locations of the moving object along a temporal-spatial path that the moving object travels from a starting location through intermediate locations to a destination location; and
performing a query on the trajectory, wherein the query uses as an input the at least one query input parameter received from the user.
2. A computer readable medium having stored therein instructions for causing a processor to execute the method of claim 1 .
3. The method of claim 1 , further comprising providing a notification to the user based on a result of the query.
4. The method of claim 1 , further comprising sending to a second user, via a wireless communication link, a notification based on a result of the query.
5. The method of claim 1 , further comprising sending to a mobile user a notification based on a result of the query.
6. The method of claim 1 , further comprising displaying a result of the query to the user on a graphical output device.
7. The method of claim 1 , wherein accessing a trajectory for a moving object comprises retrieving the trajectory from an object-oriented database or a relational database.
8. The method of claim 1 , wherein accessing the trajectory for a moving object comprises retrieving the trajectory from a database, and wherein the database stores respective trajectories for a plurality of moving objects.
9. The method of claim 1 , further comprising:
saving the query; and
re-performing the query at a later time.
10. The method of claim 1 , further comprising:
receiving an actual location of the moving object and a time that the moving object was at the actual location;
updating the trajectory of the moving object based on the actual location of the moving object and the time that the moving object was at the actual location; and
re-performing the query on the updated trajectory.
11. The method of claim 10 , further comprising providing a notification to the user based on a result of the re-performed query.
12. The method of claim 1 , wherein the query receives as input a location and a time, wherein the query returns a statistical likelihood that the moving object will be at the location by the time, wherein the query also returns a location having the highest statistical likelihood that the moving object will be there at the time, and wherein the statistical likelihood is based at least in part on the permissible spatial and temporal uncertainties in the actual locations of the moving object.
13. The method of claim 12 , wherein the at least one query input parameter includes the location or the time.
14. The method of claim 1 , wherein the query receives as input a location and a time interval, wherein the query returns a statistical likelihood that the moving object will be at the location during at least part of the time interval, and wherein the statistical likelihood is based at least in part on the permissible spatial and temporal uncertainties in the actual locations of the moving object.
15. The method of claim 14 , wherein the at least one query input parameter includes the location or the time interval.
16. The method of claim 1 , wherein the query receives as input a spatial region and a time, wherein the query returns a statistical likelihood that the moving object will be within the spatial region at the time, and wherein the statistical likelihood is based at least in part on the permissible spatial and temporal uncertainties in the actual locations of the moving object.
17. The method of claim 16 , wherein the at least one query input parameter includes the spatial region or the time.
18. The method of claim 1 , wherein the query receives as input a spatial region and a time interval, wherein the query returns a statistical likelihood that the moving object will be within the spatial region during at least part of the time interval, and wherein the statistical likelihood is based at least in part on the permissible spatial and temporal uncertainties in the actual locations of the moving object.
19. The method of claim 18 , wherein the at least one query input parameter includes the spatial region or the time interval.
20. A method of querying trajectory data, the method comprising:
receiving from a user at least one query input parameter;
accessing respective trajectories for each of a plurality of moving objects, wherein each respective trajectory defines permissible spatial and temporal uncertainties in actual locations of one of the moving objects relative to expected locations of the moving object along a temporal-spatial path that the moving object travels from a starting location through intermediate locations to a destination location; and
performing a query on the trajectories, wherein the query uses as an input the at least one query input parameter.
21. A computer readable medium having stored therein instructions for causing a processor to execute the method of claim 20 .
22. The method of claim 20 , further comprising notifying the user of a result of the query.
23. The method of claim 20 , further comprising sending to a second user, via a wireless communication link, a notification based on a result of the query.
24. The method of claim 20 , further comprising sending to a mobile user a notification based on a result of the query.
25. The method of claim 20 , wherein accessing the respective trajectories comprises retrieving the respective trajectories from an object-oriented database or a relational database.
26. The method of claim 20 , further comprising:
saving the query;
receiving from the user an indication to re-perform the query; and
responsively re-performing the query.
27. The method of claim 20 , further comprising:
receiving an actual location of one of the moving objects and a time that the moving object was at the actual location;
updating the trajectory of the moving object based on the actual location of the moving object and the time that the moving object was at the actual location; and
re-performing the query using the updated trajectory.
28. The method of claim 20 , wherein receiving from a user at least one query input parameter comprises:
displaying a map to the user on a graphical user interface; and
receiving from the user a selection of a location on the map.
29. The method of claim 20 , wherein receiving from a user at least one query input parameter comprises:
displaying a map to the user on a graphical user interface; and
receiving from the user a selection of a geographic region on the map.
30. The method of claim 20 , wherein receiving from a user at least one query input parameter comprises:
electronically displaying a map to the user; and
detecting that the user has drawn a closed region on the map with an input device.