2F-85 & 2F-140 - Instruction Manual
1.3. Object picking
The 2-Finger Gripper has a single actuator for opening and closing the fingers. The fingers automatically adapt to the shape of the
object manipulated.
Fingers will adopt either a parallel grasp or encompassing grasp as shown in the figure below.
Info
Closing or opening is done via the "Go to requested position" command sent to the gripper. Whether the fingers close to
produce an encompassing or parallel grasp is determined mechanically by:
l
The objects's geometry;
l
The relative position of the object with respect to the gripper.
In other words, picking the same object could result in either an encompassing or fingertip grasp based on an object's
position and geometry.
Fig. 1-3: 2-Finger parallel and encompassing grips.
Info
It is important to note that a fingertip grasp can only be performed when the fingers touch the object with the upper section
of the distal phalanxes first. Inversely, for an encompassing grip, the fingers must touch the object with the proximal or the
lower section of the distal phalanxes first. Also, to ensure stability, the object should be held against the gripper palm while
performing an encompassing grip. Refer to Fig. 1-5 for a visual representation of the parallel and encompassing grasp
regions on the distal phalanx of the 2-Finger Gripper.
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