Determining and aligning a position of a device and a position of a wireless access point (AP)

A computer readable memory having stored therein instructions, that when executed by one or more processors, cause the one or more processors to perform functions comprising:

• receiving traces of data, wherein respective data is collected by sensors of a device over a plurality of locations and over time periods, and wherein a respective trace of data includes received signal strength indication (RSSI) data for a plurality of wireless access points (AP);
• selecting a set of traces and a given wireless AP among the traces of data for which data is indicative of a threshold amount of information to estimate a position of the device over the time periods and a position of the given wireless AP;
• selecting first characteristics from the set of traces to remain constant and second characteristics from the set of traces to be variable;
• selecting a localization constraint that provides one or more boundaries on the position of the device over the time periods and the position of the given wireless AP;
• performing a simultaneous localization and mapping (SLAM) optimization of the position of the device and the position of the given wireless AP, over a plurality of iterations, based on the localization constraint with the first characteristics held constant and the second characteristics allowed to vary;
• for the plurality of iterations, (i) selecting the set of traces based on the traces of data having an amount of GPS positioning data being less than a given amount of GPS positioning data in a previously selected set of traces, and (ii) performing the SLAM optimization based on the selected set of traces;
• and
• based on the iterative optimizations, providing an estimate of the position of the device over the time periods and an estimate of the position of the given wireless AP.

A system comprising:

• one or more processors;
• data storage configured to store instructions that, when executed by the one or more processors, cause the system to perform functions comprising:
• receiving traces of data, wherein respective data is collected by sensors of a device over a plurality of locations and over time periods, and wherein a respective trace of data includes received signal strength indication (RSSI) data for a plurality of wireless access points (AP);
• selecting a set of traces and a given wireless AP among the traces of data for which data is indicative of a threshold amount of information to estimate a position of the device over the time periods and a position of the given wireless AP;
• selecting first characteristics from the set of traces to remain constant and second characteristics from the set of traces to be variable;
• selecting a localization constraint that provides one or more boundaries on the position of the device over the time periods and the position of the given wireless AP;
• performing a simultaneous localization and mapping (SLAM) optimization of the position of the device and the position of the given wireless AP, over a plurality of iterations, based on the localization constraint with the first characteristics held constant and the second characteristics allowed to vary;
• for the plurality of iterations, (i) selecting the set of traces based on the traces of data having an amount of GPS positioning data being less than a given amount of GPS positioning data in a previously selected set of traces, and (ii) performing the SLAM optimization based on the selected set of traces;
• and
• based on the iterative optimizations, providing an estimate of the position of the device over the time periods and an estimate of the position of the given wireless AP.