Page 126 - Human Inspired Dexterity in Robotic Manipulation

124 Human Inspired Dexterity in Robotic Manipulation

Fingertip
X

1 [mm]
Z Y
Thin plate Force gauge
Pressure sensitive paper
Z

X Y

Fig. 7.11 Experimental setup for investigating contact pressure uniformity in a fingertip
in contact with a line surface.

and connected to a positioning stage to guide the fingertip to be in contact
with the thin duralumin plate (1 mm thick) through the pressure sensitive
paper with a constant load of 30 N. In addition, the edges of the thin plate
were rounded, and a pressure-sensitive paper was placed over them for
determining the contact pressure distribution. The Prescale mat was not
used because high pressure was expected due to the sharpness of the edge.
The other conditions were set the same as those in the previous experiment,
as listed in Table 7.2.
Fig. 7.12 shows the scanned dot patterns, whereas Fig. 7.13 displays the
derived contact pressure distribution. The grasping was done with through
enveloping, which means that the contact area was not only the front sur-
face, but also the sides of the thin plate. In examining the experimental

(A) (B) (C)
Fig. 7.12 Scanned dot patterns for each fingertip when in contact with a line surface.
(A) Fluid fingertip (fluid pressure at no-contact: 30 kPa). (B) Fluid fingertip (fluid pressure
at no-contact: 10 kPa). (C) Silicon fingertip.