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

Inventor: Hidekazu Tsukiji (Tokyo, JP)

Assignee: Asahi Kasei Microdevices Corporation

G01B7/008 G01B7/30 G01D5/145

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Quick Facts

Patent No.: US 12663252
App. No.: 18/444,766
Granted: Jun 23, 2026
Kind: B2

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Abstract

Provided is an estimation apparatus for estimating a position and 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 estimation apparatus includes an update unit which updates the reference information indicating a combination of measured values based on a correlation of measured values of the at least two components in the at least one direction measured by the at least one magnetic sensor.

Claims (39)

1 . An estimation apparatus that estimates 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 estimation apparatus comprising:

one or more processors, wherein

the one or more processors:

estimate, 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

update 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.

2 . The estimation apparatus according to claim 1 , wherein

the movable mechanism allows a first operation that causes the second portion to change from a first position or a first attitude to a second position or a second attitude with respect to the first portion, and a second operation that causes the second portion to change from the second position or the second attitude to the first position or the first attitude with respect to the first portion, and

3 . The estimation apparatus according to claim 2 , wherein

the one or more processors update the reference information based on the correlation of the measured values of the at least two components in the at least one direction measured by the at least one magnetic sensor when the second portion is in the first position or the first attitude with respect to the first portion, or the correlation of the measured values of the at least two components in the at least one direction measured by the at least one magnetic sensor when the second portion is in the second position or the second attitude with respect to the first portion.

4 . The estimation apparatus according to claim 1 , wherein

on a coordinate system in which a first axis represents a measured value of a component in a first direction which is measured by the at least one magnetic sensor and a second axis represents a measured value of a component in a second direction which is measured by the at least one magnetic sensor, the correlation is represented by a figure indicated by a set of coordinate values corresponding to the position or the attitude of the second portion with respect to the first portion which is indicated by a combination of the measured value of the component in the first direction which is measured by the at least one magnetic sensor and the measured value of the component in the second direction which is measured by the at least one magnetic sensor, and

the one or more processors update the reference information by performing at least one of a) expansion or reduction or b) movement to align the figure on the coordinate system onto coordinate values respectively indicated by a plurality of measured values of the component in the first direction and a plurality of measured values of the component in the second direction which are measured by the at least one magnetic sensor.

5 . The estimation apparatus according to claim 4 , wherein

the correlation includes

a first combination group of the measured value of the component in the first direction and the measured value of the component in the second direction which are measured by the at least one magnetic sensor according to the position or the attitude of the second portion with respect to the first portion during the first operation, and

a second combination group of the measured value of the component in the first direction and the measured value of the component in the second direction which are measured by the at least one magnetic sensor according to the position or the attitude of the second portion with respect to the first portion during the second operation, and

the figure includes a first line corresponding to the first combination group and a second line corresponding to the second combination group.

6 . The estimation apparatus according to claim 4 , wherein the one or more processors update the reference information by performing at least one of a) the expansion or the reduction or b) the movement of the figure on the coordinate system to align a predetermined feature point on the figure to any of coordinate values respectively indicated by the plurality of measured values of the component in the first direction and the plurality of measured values of the component in the second direction which are measured by the at least one magnetic sensor.

7 . The estimation apparatus according to claim 6 , wherein

the predetermined feature point on the figure includes a point at which the component of the first axis becomes maximum or minimum, and a point at which the component of the second axis becomes maximum or minimum.

8 . The estimation apparatus according to claim 4 , wherein

the one or more processors does not update the reference information when it is not possible to align, by performing at least one of a) expansion or reduction or b) movement, the figure on the coordinate system onto the coordinate values respectively indicated by the plurality of measured values of the component in the first direction and the plurality of measured values of the component in the second direction which are measured by the at least one magnetic sensor during the first operation or during the second operation to a predetermined degree of coincidence or more.

9 . The estimation apparatus according to claim 1 , wherein

the reference information is represented by each of predetermined fit functions indicating variation of the measured value of the at least one component in the at least one direction of the at least one magnetic sensor according to the position or the attitude of the second portion with respect to the first portion, and

the one or more processors update the reference information by adjusting a specific coefficient of each of the predetermined fit functions based on the correlation of the measured values of the at least two components in the at least one direction measured by the at least one magnetic sensor.

10 . An apparatus comprising:

the estimation apparatus according to claim 1 ;

the first portion;

the second portion; and

the movable mechanism.

11 . An estimation method of 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 estimation method comprising:

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.

12 . 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:

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.