US 11,940,303 B2
Position detection device and position detection method
Tetsuya Narita, Tokyo (JP); and Masahiro Fujita, Saitama (JP)
Assigned to SONY CORPORATION, Tokyo (JP)
Appl. No. 16/489,029
Filed by SONY CORPORATION, Tokyo (JP)
PCT Filed Mar. 1, 2018, PCT No. PCT/JP2018/007815
§ 371(c)(1), (2) Date Aug. 27, 2019,
PCT Pub. No. WO2018/190018, PCT Pub. Date Oct. 18, 2018.
Claims priority of application No. 2017-079612 (JP), filed on Apr. 13, 2017.
Prior Publication US 2020/0003586 A1, Jan. 2, 2020
Int. Cl. G01D 5/244 (2006.01); G01B 7/30 (2006.01); G01D 5/245 (2006.01); G01R 33/06 (2006.01); G01D 5/347 (2006.01)
CPC G01D 5/24419 (2013.01) [G01B 7/30 (2013.01); G01D 5/2455 (2013.01); G01R 33/06 (2013.01); G01D 5/34794 (2021.05)] 13 Claims
OG exemplary drawing
 
1. A position detection device comprising:
circuitry configured to:
calculate a reference position of a moving body on a basis of a first signal and a second signal, the first signal being detected from a first track provided on the moving body and having a scale of predetermined cycles, and the second signal being detected from a second track provided on the moving body and having a scale of cycles less than the predetermined cycles;
specify a cycle corresponding to the reference position of the moving body among the scale of cycles of the first track on a basis of the reference position;
calculate an interpolation angle of the moving body in the specified cycle on a basis of the first signal;
calculate an absolute position of the moving body on a basis of a combination of the specified cycle and the interpolation angle;
detect a position deviation occurs between the reference position and the absolute position on a basis of a difference between the reference position and the absolute position being greater than a predetermined value set based on a total number of the predetermined cycles of the first track;
determine, based on the detected position deviation, a total number of cycles included in the difference between the reference position and the absolute position; and
calculate a corrected absolute position,
wherein the calculation of the corrected absolute position includes subtracting, from the absolute position, the determined total number of cycles included in the difference between the reference position and the absolute position,
wherein the total number of cycles included in the difference between the reference position and the absolute position is determined by rounding a value obtained by dividing the difference between the reference position and the absolute position by a number of degrees included in a cycle in the first track, and
wherein the corrected absolute position is determined by subtracting from the absolute position a value obtained by multiplying the total number of cycles by the number of degrees included in the cycle in the first track.