Estimation apparatus, apparatus, estimation method and computer readable storage medium

A non-transitory computer readable storage medium storing a program for casing a computer to function as an estimation apparatus for estimating at least one of a position or an attitude of a second portion with respect to a first portion in an apparatus including the first portion, the second portion, a movable mechanism which changes at least one of the position or the attitude of the second portion with respect to the first portion, at least one magnetic sensor provided in one of the first portion or the second portion, and a magnet section which is provided in another of the first portion or the second portion and which provides a magnetic field measured by the at least one magnetic sensor, the program causing the computer to execute:

• estimating, based on a measured value of at least one component in at least one direction measured by the at least one magnetic sensor at a first time point and reference information indicating a measured value of at least one component in at least one direction of the at least one magnetic sensor according to a position or an attitude of the second portion with respect to the first portion, a position or an attitude of the second portion with respect to the first portion at the first time point;
• and
• updating the reference information based on a correlation of measured values of at least two components in the at least one direction measured by the at least one magnetic sensor.