Position estimation system and position estimation method

A position estimation method performed by at least one processor for estimating a position of a mobile device carried by a user, the position estimation method comprising:

• acquiring reception strength of signals of the mobile device at communicators configured to wirelessly communicate with the mobile device and installed at different positions in a vehicle, respectively;
• acquiring a time-of-flight related value, which is a parameter different from the reception strength, that directly or indirectly indicates a time of flight of radio waves sent from the communicators to the mobile device;
• correct the time-of-flight related value using a correction function that is for acquiring a corrected time-of-flight related value by inputting the reception strength and the time-of-flight related value acquired in the acquiring;
• and
• estimate the position of the mobile device using the corrected time-of-flight related value, wherein
• the correction function is a function determined using teaching data including positions of the mobile device and the reception strength and the time-of-flight related values at the positions of the mobile device, and
• a data volume of the correction function is smaller than a data volume of the teaching data.

A position estimation system configured to estimate a position of a mobile device relative to a vehicle by wirelessly communicating with the mobile device carried by a user, the position estimation system comprising:

• communicators configured to wirelessly communicate with the mobile device and installed at different positions in the vehicle;
• at least one processor;
• and
• at least one memory storing computer program code, wherein
• the at least one memory and the computer program code are configured, with the at least one processor, to cause the position estimation system to carry out:
• controlling operation of the communicators;
• estimating a position of the mobile device;
• acquiring reception strength of signals of the mobile device at the communicators, respectively;
• acquiring a time-of-flight related value, which is a parameter different from the reception strength, that directly or indirectly indicates a time of flight of radio waves sent from the communicators to the mobile device;
• correcting the time-of-flight related value using a correction function that is for acquiring a corrected time-of-flight related value by inputting the reception strength and the time-of-flight related value acquired by the communication controller;
• and
• estimating the position of the mobile device using the corrected time-of-flight related value,
• the correction function is a function determined using teaching data including positions of the mobile device and the reception strength and the time-of-flight related values at the positions of the mobile device, and
• a data volume of the correction function is smaller than a data volume of the teaching data.