US 12,269,175 B2
Curved surface following control method for robot
Masanori Ito, Kobe (JP); and Hiroki Suemoto, Kobe (JP)
Assigned to KAWASAKI JUKOGYO KABUSHIKI KAISHA, Kobe (JP)
Appl. No. 17/785,402
Filed by Kawasaki Jukogyo Kabushiki Kaisha, Kobe (JP)
PCT Filed Dec. 15, 2020, PCT No. PCT/JP2020/046780
§ 371(c)(1), (2) Date Jun. 15, 2022,
PCT Pub. No. WO2021/125175, PCT Pub. Date Jun. 24, 2021.
Claims priority of application No. 2019-226602 (JP), filed on Dec. 16, 2019.
Prior Publication US 2023/0028732 A1, Jan. 26, 2023
Int. Cl. B25J 9/16 (2006.01)
CPC B25J 9/1694 (2013.01) [B25J 9/1633 (2013.01)] 3 Claims
OG exemplary drawing
 
1. A curved surface following control method for controlling a robot including a hand part to which a work tool is attached, an arm part connected to the hand part, and a controller for controlling operation of the hand part and the arm part, the curved surface following control method comprising:
a normal direction identification process that includes, based on a formula for approximating a shape of a target workpiece including a curved surface, identifying a normal direction of a virtual shape which is a shape represented by the formula at a virtual position where the work tool attached to the hand part contacts the virtual shape; and
a work tool posture control process that includes bringing the work tool attached to the hand part into contact with the target workpiece at a corresponding position which is a position corresponding to the virtual position on a surface of the target workpiece, in a posture along the normal direction identified in the normal direction identification process, wherein
the robot or the work tool includes a force sensor,
a traveling path of the work tool along a surface of the virtual shape represented by the formula is expressed as a group of work tool travel direction vectors that indicate a movement in a tangent plane oriented perpendicular to the normal direction, and
in the work tool posture control process, moving the work tool in the posture along the normal direction along respective work tool travel direction vectors, and correcting a position of the work tool in a direction of advancing inward from the virtual shape or retreating outward from the virtual shape according to a detection value of the force sensor.