US 12,330,305 B2
Robot system and method for controlling same
Zhiqiang Liu, Kyoto (JP); Yuki Tsuchihashi, Kyoto (JP); and Masahiro Murai, Kyoto (JP)
Assigned to OMRON CORPORATION, Kyoto (JP)
Filed by OMRON Corporation, Kyoto (JP)
Filed on Feb. 23, 2023, as Appl. No. 18/173,137.
Claims priority of application No. 2022-038609 (JP), filed on Mar. 11, 2022.
Prior Publication US 2023/0286145 A1, Sep. 14, 2023
Int. Cl. B25J 9/00 (2006.01); B25J 9/16 (2006.01); B25J 13/08 (2006.01)
CPC B25J 9/1633 (2013.01) [B25J 9/1687 (2013.01); B25J 13/082 (2013.01)] 9 Claims
OG exemplary drawing
 
1. A robot system for inserting a workpiece including an engagement portion into a part including a receiving portion corresponding to the engagement portion to assemble the workpiece with the part, the robot system comprising:
a robot configured to grip the workpiece;
a force sensor located on the robot to measure a force and a moment acting on the workpiece; and
a controller configured to control the robot, wherein:
the controller monitors, while moving the workpiece in a direction along a first axis and inserting the workpiece into the part, a change in a force F in the direction along the first axis and a change in a moment M about a second axis perpendicular to the first axis measured by the force sensor to determine a state of assembly of the workpiece with the part,
the controller determines that the engagement portion and the receiving portion are engaged with each other and that the workpiece is assembled with the part normally in response to a decrease in the force F relative to a maximum value Fmax of the force F recorded at and after a predetermined determination start point exceeding a first threshold, and
the controller determines that the workpiece is assembled with the part normally in response to the moment M being less than a second threshold and a predetermined time elapsing from the predetermined determination start point before the decrease in the force F relative to the maximum value Fmax of the force F exceeds the first threshold.