Estimation apparatus, estimation method and computer readable medium
An estimation apparatus comprises: a collection unit configured to collect a plurality of pieces of update information used for updating reference information, which indicates measurement values in accordance with a position or an attitude of a second portion against a first portion which is measured by at least one magnetic sensor while changing at least one of the position and the attitude of the second portion against the first portion over a predetermined movable range; a clustering unit configured to perform clustering on the plurality of pieces of update information according to a predetermined classification condition; and an updating unit configured to update the reference information based on at least one piece of update information included in a maximum class into which a highest number of pieces of information are classified among the plurality of pieces of update information.
1. An estimation apparatus which is configured to estimate at least one of a position and an attitude of a second portion against a first portion in an apparatus comprising the first portion, the second portion, a movable mechanism which is configured to change at least one of a position and an attitude of the second portion against the first portion, at least one magnetic sensor which is provided in one of the first portion or the second portion, a magnet unit which is provided in the other of the first portion or the second portion and which is configured to provide a magnetic field which is measured by the at least one magnetic sensor, wherein the estimation apparatus comprises:
an estimation unit configured to estimate a position or an attitude of the second portion against the first portion at a first time point, based on a measurement value at the first time point measured by the at least one magnetic sensor and reference information indicating measurement values of the at least one magnetic sensor in accordance with the position or the attitude of the second portion against the first portion;
a collection unit configured to collect a plurality of pieces of update information used for updating the reference information, which indicates measurement values in accordance with the position or the attitude of the second portion against the first portion which is measured by the at least one magnetic sensor while changing at least one of the position or the attitude of the second portion against the first portion over a predetermined movable range;
a clustering unit configured to perform clustering on the plurality of pieces of update information according to a predetermined classification condition; and
an updating unit configured to update the reference information based on at least one piece of update information included in a maximum class into which a highest number of pieces of information are classified among the plurality of pieces of update information.
2. The estimation apparatus according to claim 1 , wherein the updating unit is configured not to update the reference information based on the at least one piece of update information included in the maximum class when a number of the update information included in the maximum class is less than a reference number defined based on a number of the plurality of pieces of update information.
3. The estimation apparatus according to claim 1 , wherein the updating unit is configured not to update the reference information based on the at least one piece of update information included in the maximum class when a number of the update information included in the maximum class is less than a majority of a number of the plurality of pieces of update information.
4. The estimation apparatus according to claim 1 , wherein the clustering unit is configured to perform clustering on the plurality of pieces of update information and the reference information according to the predetermined classification condition.
5. The estimation apparatus according to claim 4 , wherein the clustering unit is configured to:
when the reference information is included in the maximum class, update the reference information by averaging, for each position or attitude of the second portion against the first portion, each measurement value in accordance with the position or the attitude of the second portion against the first portion indicated in the at least one piece of update information and each measurement value in accordance with the position or the attitude of the second portion against the first portion indicated in the reference information; and
when the reference information is not included in the maximum class, update the reference information by averaging, for each position or attitude of the second portion against the first portion, each measurement value in accordance with the position or the attitude of the second portion against the first portion indicated in the at least one piece of update information.
6. The estimation apparatus according to claim 1 , wherein the clustering unit is configured to update the reference information based on the latest update information among the at least one piece of update information.
7. The estimation apparatus according to claim 1 , wherein the collection unit is configured to collect the plurality of pieces of update information which indicates measurement values in accordance with the position or the attitude of the second portion against the first portion which is measured at an equal interval by the at least one magnetic sensor while changing at least one of the position or the attitude of the second portion against the first portion at a constant speed over the predetermined movable range.
8. The estimation apparatus according to claim 1 , wherein
the first portion and the second portion are configured to configure a display unit, and
the second portion is configured to change a position against the first portion by moving in a predetermined direction against the first portion and to change a width of a display screen in the predetermined direction of the display unit.
9. The estimation apparatus according to claim 1 , wherein
the first portion and the second portion are configured to configure a display unit, and
the movable mechanism is a hinge mechanism which can fold the second portion against the first portion, and
the second portion is configured to change the attitude against the first portion by rotating against the first portion via the hinge mechanism.
10. The estimation apparatus according to claim 9 , wherein
the at least one magnetic sensor is configured to be provided in the second portion,
the hinge mechanism is integrally configured with the first portion, and
the magnet unit is provided on the hinge mechanism.
11. An apparatus comprising:
the estimation apparatus according to claim 1 ;
the first portion;
the second portion; and
the movable mechanism.
12. An estimation method for estimating at least one of a position and an attitude of a second portion against a first portion in an apparatus comprising the first portion, the second portion, a movable mechanism which is configured to change at least one of a position and an attitude of the second portion against the first portion, at least one magnetic sensor which is provided in one of the first portion or the second portion, a magnet unit which is provided in the other of the first portion or the second portion and which is configured to provide a magnetic field which is measured by the at least one magnetic sensor, wherein the estimation method comprises:
estimating a position or an attitude of the second portion against the first portion at a first time point, based on a measurement value at the first time point measured by the at least one magnetic sensor and reference information indicating measurement values of the at least one magnetic sensor in accordance with the position or the attitude of the second portion against the first portion;
collecting a plurality of pieces of update information used for updating the reference information, which indicates measurement values in accordance with the position or the attitude of the second portion against the first portion which is measured by the at least one magnetic sensor while changing at least one of the position or the attitude of the second portion against the first portion over a predetermined movable range;
performing clustering on the plurality of pieces of update information according to a predetermined classification condition; and
updating the reference information based on at least one piece of update information included in a maximum class into which a highest number of pieces of information are classified among the plurality of pieces of update information.
13. A non-transitory computer readable medium which is configured to store a program for causing a computer to function as an estimation apparatus which is configured to estimate at least one of a position and an attitude of a second portion against a first portion in an apparatus comprising the first portion, the second portion, a movable mechanism which is configured to change at least one of a position and an attitude of the second portion against the first portion, at least one magnetic sensor which is provided in one of the first portion or the second portion, a magnet unit which is provided in the other of the first portion or the second portion and which is configured to provide a magnetic field which is measured by the at least one magnetic sensor, wherein the computer readable medium configured to store the program causes the computer to perform:
estimating a position or an attitude of the second portion against the first portion at a first time point, based on a measurement value at the first time point measured by the at least one magnetic sensor and reference information indicating measurement values of the at least one magnetic sensor in accordance with the position or the attitude of the second portion against the first portion;
collecting a plurality of pieces of update information used for updating the reference information, which indicates measurement values in accordance with the position or the attitude of the second portion against the first portion which is measured by the at least one magnetic sensor while changing at least one of the position or the attitude of the second portion against the first portion over a predetermined movable range;
performing clustering on the plurality of pieces of update information according to a predetermined classification condition; and
updating the reference information based on at least one piece of update information included in a maximum class into which a highest number of pieces of information are classified among the plurality of pieces of update information.