Detection of a physical collision between two client devices in a location sharing system
The invention provides methods, systems, and devices for detecting a physical collision between two client devices based on sensor data. A server computer receives a first collision signature from a first client device, and a second collision signature from a second client device. Based on determining that a correlation of the first collision signature and the second collision signature does not achieve a detection threshold, the server computer lowers, for a limited period of time, the detection threshold. If the server computer receives, within the limited period of time, a third collision signature from the first client device, and a fourth collision signature from the second client device, and determines that a correlation of the third collision signature and the fourth collision signature achieves the lowered detection threshold, the server computer detects a collision between the first and second client devices.
1. A method comprising:
receiving, at a server computer, a first collision signature from a first client device, and a second collision signature from a second client device;
determining that a first timespan between a timestamp of the first collision signature and a timestamp of the second collision signature is below a time threshold;
increasing, based on determining that the first timespan is below the time threshold, the time threshold for a limited period of time;
receiving, at the server computer and within the limited period of time, a third collision signature from the first client device, and a fourth collision signature from the second client device;
determining that a second timespan between a timestamp of the third collision signature and a timestamp of the fourth collision signature meets the time threshold; and
detecting, based on determining that the second timespan meets the time threshold, a collision associated with the first and second client devices.
2. The method of claim 1 , wherein each collision signature includes a sequence of instant acceleration readings acquired by a corresponding client device.
3. The method of claim 1 , further comprising:
receiving location data from the first client device;
determining a plurality of visit points of the first client device by aggregating the location data received from the first client device;
receiving location data from the second client device;
determining a plurality of visit points of the second client device by aggregating the location data received from the second client device;
determining that a location of the first collision signature corresponds to one of the plurality of visit points of the first client device; and
determining that a location of the second collision signature corresponds to one of the plurality of visit points of the second client device.
4. The method of claim 3 , further comprising:
determining that a location of the third collision signature corresponds to one of the plurality of visit points of the first client device; and
determining that a location of the fourth collision signature corresponds to one of the plurality of visit points of the second client device.
5. The method of claim 1 , further comprising:
creating, in response to detecting the collision, a communication session between the first and the second client devices via the server computer.
6. The method of claim 1 , wherein the first client device is associated with a first user, and the second client device is associated with a second user.
7. The method of claim 6 , further comprising:
sending, in response to detecting the collision, a notification to a third client device associated with a third user that is connected, in a social graph, with both the first and second users.
8. A system comprising:
a processor; and
a memory storing instructions that, when executed by the processor, configure the processor to perform operations comprising:
receiving a first collision signature from a first client device, and a second collision signature from a second client device;
determining that a first timespan between a timestamp of the first collision signature and a timestamp of the second collision signature is below a time threshold;
increasing, based on determining that the first timespan is below the time threshold, the time threshold for a limited period of time;
receiving, within the limited period of time, a third collision signature from the first client device, and a fourth collision signature from the second client device;
determining that a second timespan between a timestamp of the third collision signature and a timestamp of the fourth collision signature meets the time threshold; and
detecting, based on determining that the second timespan meets the time threshold, a collision associated with the first and second client devices.
9. The system of claim 8 , wherein each collision signature includes a sequence of instant acceleration readings acquired by a corresponding client device.
10. The system of claim 8 , the operations further comprising:
receiving location data from the first client device;
determining a plurality of visit points of the first client device by aggregating the location data received from the first client device;
receiving location data from the second client device;
determining a plurality of visit points of the second client device by aggregating the location data received from the second client device;
determining that a location of the first collision signature corresponds to one of the plurality of visit points of the first client device; and
determining that a location of the second collision signature corresponds to one of the plurality of visit points of the second client device.
11. The system of claim 10 , further comprising:
determining that a location of the third collision signature corresponds to one of the plurality of visit points of the first client device; and
determining that a location of the fourth collision signature corresponds to one of the plurality of visit points of the second client device.
12. The system of claim 8 , further comprising:
creating, in response to detecting the collision, a communication session between the first and the second client devices.
13. The system of claim 8 , wherein the first client device is associated with a first user, and the second client device is associated with a second user.
14. The system of claim 13 , the operations further comprising:
sending, in response to detecting the collision, a notification to a third client device associated with a third user that is connected, in a social graph, with both the first and second users.
15. A non-transitory computer-readable storage medium, the computer-readable storage medium including instructions that when executed by a computer, cause the computer to perform operations comprising:
receiving a first collision signature from a first client device, and a second collision signature from a second client device;
determining that a first timespan between a timestamp of the first collision signature and a timestamp of the second collision signature is below a time threshold;
increasing, based on determining that the first timespan is below the time threshold, the time threshold for a limited period of time;
receiving, within the limited period of time, a third collision signature from the first client device, and a fourth collision signature from the second client device;
determining that a second timespan between a timestamp of the third collision signature and a timestamp of the fourth collision signature meets the time threshold; and
detecting, based on determining that the second timespan meets the time threshold, a collision associated with the first and second client devices.
16. The computer-readable storage medium of claim 15 , wherein each collision signature includes a sequence of instant acceleration readings acquired by a corresponding client device.
17. The computer-readable storage medium of claim 15 , the operations further comprising:
receiving location data from the first client device;
determining a plurality of visit points of the first client device by aggregating the location data received from the first client device;
receiving location data from the second client device;
determining a plurality of visit points of the second client device by aggregating the location data received from the second client device;
determining that a location of the first collision signature corresponds to one of the plurality of visit points of the first client device; and
determining that a location of the second collision signature corresponds to one of the plurality of visit points of the second client device.
18. The computer-readable storage medium of claim 17 , further comprising:
determining that a location of the third collision signature corresponds to one of the plurality of visit points of the first client device; and
determining that a location of the fourth collision signature corresponds to one of the plurality of visit points of the second client device.
19. The computer-readable storage medium of claim 18 , further comprising:
creating, in response to detecting the collision, a communication session between the first and the second client devices.
20. The computer-readable storage medium of claim 18 , wherein the first client device is associated with a first user, and the second client device is associated with a second user.