US 12,353,187 B2
Method for positioning a limp, flat workpiece and positioning apparatus
Alexander Bley, Munich (DE); Tim Doerks, Munich (DE); and Till Rickert, Munich (DE)
Assigned to SEWTS GMBH, Munich (DE)
Appl. No. 17/624,529
Filed by SEWTS GMBH, Munich (DE)
PCT Filed Jul. 3, 2019, PCT No. PCT/EP2019/067891
§ 371(c)(1), (2) Date Jan. 3, 2022,
PCT Pub. No. WO2021/001039, PCT Pub. Date Jan. 7, 2021.
Prior Publication US 2022/0244699 A1, Aug. 4, 2022
Int. Cl. G05B 19/402 (2006.01)
CPC G05B 19/402 (2013.01) [G05B 2219/50047 (2013.01)] 20 Claims
OG exemplary drawing
 
1. A method of positioning a limp flat workpiece using a positioning device which includes at least one control unit, a camera, at least one first gripper and at least one second gripper, the method comprising the steps of:
a) providing the flat workpiece in a random state on a manipulation surface;
b) generating, by the camera, a camera image showing the flat workpiece;
c) identifying, by a first machine learning module of the control unit, a grippable edge of the flat workpiece by extracting characteristic image features of the camera image;
d) determining, by a second machine learning module of the control unit, a first gripping point for the first gripper at the grippable edge; and
e) determining, by the second machine learning module of the control unit, a second gripping point for the second gripper at the grippable edge, the second gripping point being spaced apart from the first gripping point,
wherein the flat workpiece is held by the second gripper and the first gripper is moved along the gripped edge until the first gripper grips a first corner of the flat workpiece, and/or
the flat workpiece is held by the first gripper and the second gripper is moved along the gripped edge until the second gripper grips a second corner of the flat workpiece, and
wherein prior to generating the camera image, an area of contact of the flat workpiece with the manipulation surface is enlarged starting from a random state.