US 12,263,601 B2
Angle calibration method
Terumasa Yoshida, Kobe (JP)
Assigned to KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
Appl. No. 18/008,301
Filed by KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
PCT Filed Jun. 4, 2021, PCT No. PCT/JP2021/021386
§ 371(c)(1), (2) Date Dec. 5, 2022,
PCT Pub. No. WO2021/246521, PCT Pub. Date Dec. 9, 2021.
Claims priority of application No. 2020-098368 (JP), filed on Jun. 5, 2020.
Prior Publication US 2023/0173680 A1, Jun. 8, 2023
Int. Cl. B25J 9/16 (2006.01); G01B 5/14 (2006.01)
CPC B25J 9/1692 (2013.01) [B25J 9/1664 (2013.01); G01B 5/14 (2013.01)] 11 Claims
OG exemplary drawing
 
1. An angle calibration method for calibrating an angle of a robot, the robot including
a first member,
a second member that is coupled to the first member in a relatively rotatable manner, and
an actuator that changes an angle of the second member relative to the first member in accordance with a command value,
the angle calibration method comprising:
a first step of obtaining a measurement object distance, which is a distance between two measurement object portions including a first measurement object portion in the first member and a second measurement object portion in the second member, by measuring a distance between wall surfaces of the two measurement object portions, the measurement being made while the actuator is given an arbitrary command value; and
a second step of obtaining an angular difference by calculation, the angular difference corresponding to a difference in distance between two measurement object portions, the calculation being made based on a reference measurement object distance obtained in the past and the measurement object distance obtained in the first step, the reference measurement object distance having been obtained by measuring the measurement object distance while the actuator was given an arbitrary command value, wherein
one of the two measurement object portions is a pin that protrudes from the first member,
the other of the two measurement object portions is a pin that protrudes from the second member, and
directions in which the two pins protrude are opposite to each other.