
188
possesses the nonlinearity, and is guessed to origi-
nate in the equal volume transformation of the
resin from the shape. Figure 10 shows the stiffness
change when assuming 0.0 ≤ δx ≤ 12.0 [mm]. Here,
it can be confirmed that the stiffness value has
changed by compressing x axially. Moreover, it can
be confirmed that the deeper amount z of pushing
is, the bigger the stiffness change is.
4.3 Verification of the softness control
The discrimination test has been conducted to con-
firm whether the sense of touch changed by the
proposed principle. In the examination, subjects
identified the difference of softness by a different
compression distance ...