Wi-Fi enhanced tracking algorithms
Disclosed herein is the use of Wi-Fi based location estimates of a mobile device to provide global offset corrections (including automated initialization) and enhanced navigation accuracy through delivery of heading corrections. In an embodiment, dead reckoning tracking data may be received for a tracked subject. The tracking data includes a plurality of tracking points forming a tracking path of the tracked subject. A Wi-Fi position system location estimate is also obtained. The Wi-Fi position system location estimate is one of a plurality of Wi-Fi position system location estimates correlated to the dead reckoning tracking data. And a tracking related parameter is determined based on the correlation of the dead reckoning tracking data to the Wi-Fi position system location estimate.
1. A computer-implemented method of tracking a trackee, the method being implemented by a computer that includes a physical processor, the method comprising:
obtaining dead reckoning tracking data for a tracked subject, wherein the dead reckoning tracking data includes a plurality of tracking points forming a tracking path of the tracked subject;
obtaining a at least one weighted Wi-Fi position system location estimate based on a plurality of Wi-Fi position system location estimates that are correlated to the dead reckoning tracking data;
determining a tracking path adjustment parameter based on how the dead reckoning tracking data correlates to the weighted Wi-Fi position system location estimate, the tracking path adjustment parameter configured to correct the tracking path of the tracked subject.
2. The method of claim 1 , wherein the tracking path adjustment parameter comprises at least one of: a global offset, a rotation, a drift, or a scale.
3. The method of claim 1 , further comprising
assigning a reliability number to a Wi-Fi position system location estimate; and
using the reliability number to weight a contribution of the Wi-Fi position system location estimate to create the weighted Wi-Fi position system location estimate.
4. The method of claim 3 , wherein the reliability number is based on at least one of
an error property of the Wi-Fi position system location estimate, or
a consistency with a motion model of the tracked subject.
5. The method of claim 3 , further comprising:
performing path segmentation on the tracking path;
determining a shape that bounds the plurality of Wi-Fi position system location estimates;
refining segmentation of the tracking path based on the reliability numbers assigned to the plurality of Wi-Fi position system location estimates; and
performing shape matching on the refined path segmentation.
6. The method of claim 1 , further comprising:
providing a corrected path based on the tracking path adjustment parameter.
7. The method of claim 1 , wherein the dead reckoning tracking data is obtained from at least one of an inertial sensor, an optical flow sensor, a Doppler velocimeter, or a wheel encoder.
8. A computing system comprising:
a dead reckoning sensor;
a processor communicatively connected with the dead reckoning sensor, the processor adapted to execute computer-readable instructions; and
a memory communicatively coupled to said processor, said memory having stored therein computer-readable instructions that, if executed by the processor, cause the processor to perform operations comprising:
obtaining dead reckoning tracking data for a tracked subject obtained from the dead reckoning sensor, wherein the dead reckoning tracking data includes a plurality of tracking points forming a tracking path of the tracked subject;
obtaining a weighted Wi-Fi position system location estimate based on a plurality of Wi-Fi position system location estimates that are correlated to the dead reckoning tracking data;
determining a tracking path adjustment parameter based on how the dead reckoning tracking data correlates to the weighted Wi-Fi position system location estimate, the tracking path adjustment parameter configured to correct the tracking path of the tracked subject.
9. The computing system of claim 8 , wherein the tracking path adjustment parameter comprises at least one of: a global offset, a rotation, a drift, or a scale.
10. The computing system of claim 8 , further comprising instructions, if executed by the processor, cause the processor to perform operations comprising:
assigning a reliability number to a Wi-Fi position system location estimate; and
using the reliability number to weight a contribution of the Wi-Fi position system location estimate to create the weighted Wi-Fi position system location estimate.
11. The computing system of claim 10 , wherein the reliability number is based on at least one of
an error property of the Wi-Fi position system location estimate, or
a consistency with a motion model of the tracked subject.
12. The computing system of claim 10 , further comprising instructions, if executed by the processor, causes the processor to perform operations comprising:
performing path segmentation on the tracking path;
determining a shape that bounds the plurality of Wi-Fi position system location estimates;
refining segmentation of the tracking path based on the reliability numbers assigned to the plurality of Wi-Fi position system location estimates; and
performing shape matching on the refined path segmentation.
13. The computing system of claim 8 , further comprising instructions, if executed by the processor, cause the processor to perform operations comprising:
providing a corrected tracking path of the tracked subject based on the tracking path adjustment parameter.
14. The computing system claim 8 , wherein the dead reckoning sensor is at least one of an inertial sensor, an optical flow sensor, a Doppler velocimeter, or a wheel encoder.
15. A non-transitory computer readable storage device having stored therein computer-readable instructions that, if executed by a processor, cause the processor to perform operations comprising:
obtain dead reckoning tracking data for a tracked subject, wherein the dead reckoning tracking data includes a plurality of tracking points forming a tracking path of the tracked subject;
obtain a weighted Wi-Fi position system location estimate based on a plurality of Wi-Fi position system location estimates that are correlated to the dead reckoning tracking data;
determine a tracking path adjustment parameter based on how the dead reckoning tracking data correlates to the weighted Wi-Fi position system location estimate, the tracking path adjustment parameter configured to correct the tracking path of the tracked subject.
16. The non-transitory computer readable storage device of claim 15 , wherein the tracking path adjustment parameter comprises at least one of: a global offset, a rotation, a drift, or a scale.
17. The non-transitory computer readable storage device of claim 15 , further comprising instructions, if executed by the processor, causes the processor to perform operations comprising:
assign a reliability number to a Wi-Fi position system location estimate; and
use the reliability number to weight a contribution of the Wi-Fi position system location estimate to create the weighted Wi-Fi position system location estimate.
18. The non-transitory computer readable storage device of claim 17 , wherein the reliability number is based on at least one of
an error property of the Wi-Fi position system location estimate,
a second error property of a neighboring Wi-Fi position system location estimate, or
a consistency with a motion model of the tracked subject.
19. The non-transitory computer readable storage device of claim 17 , further comprising instructions, if executed by the processor, causes the processor to perform operations comprising:
perform path segmentation on the tracking path;
determine a shape that bounds the plurality of Wi-Fi position system location estimates;
refine segmentation of the tracking path based on the reliability numbers assigned to the plurality of Wi-Fi position system location estimates; and
perform shape matching on the refined path segmentation.
20. The non-transitory computer readable storage device of claim 15 , further comprising instructions, if executed by the processor, causes the processor to perform operations comprising:
provide a corrected path based on the tracking path adjustment parameter.