US 11,654,555 B2
Robot teaching system
Soonkyum Kim, Seoul (KR); Woosub Lee, Seoul (KR); Alchan Yun, Seoul (KR); Junhyoung Ha, Seoul (KR); and Deaho Moon, Seoul (KR)
Assigned to Korea Institute of Science and Technology, Seoul (KR)
Filed by KOREA INSTITUTE OF SCIENCE AND TECHNOLOGY, Seoul (KR)
Filed on Nov. 24, 2020, as Appl. No. 17/102,853.
Claims priority of application No. 10-2020-0010961 (KR), filed on Jan. 30, 2020.
Prior Publication US 2021/0237267 A1, Aug. 5, 2021
Int. Cl. B25J 9/16 (2006.01)
CPC B25J 9/163 (2013.01) 8 Claims
OG exemplary drawing
 
1. A robot teaching system, which moves a robot according to an external force applied from outside so that the robot has a location and posture intended for teaching and then teaches the location and posture of the moved robot, the robot teaching system comprising:
an arm including a plurality of articular shafts and a plurality of links connected by the plurality of articular shafts;
a plurality of strain gauges respectively coupled to frames of the plurality of links to measure a deformation value of a link that is deformed by the external force; and
a calculating device configured to estimate the external force from the deformation value of the link obtained by the plurality of strain gauges, calculate a teaching force from the external force and move the robot by an operation corresponding to the teaching force;
wherein when external forces are simultaneously applied to a plurality of points, the calculating device is configured to separately calculate teaching forces respectively applied to the plurality of the links, and to calculate a moment of a first link of the plurality of links by summing a first one of the external forces and a second one of the external forces; and
wherein calculating the teaching force includes calculating a moment of a point at which at least one strain gauge of the plurality of strain gauges is attached, based on
(i) a force and moment transmitted, due to the external force, by an end effector of the arm to a link of the plurality of links coupled to the end effector,
(ii) a reaction force applied by the link coupled to the end effector, and
(iii) a force and moment applied to a second link of the plurality of links, the second link being coupled to the link coupled to the end effector, and the at least one strain gauge being attached to the second link,
inverting a relation formula based on (i), (ii) and (iii), the relation formula relating the teaching force to a corresponding moment, and
estimating the teaching force from the moment of the point at which the at least one strain gauge of the plurality of strain gauges is attached based on the inverted relation formula.