Page 81 - Human Inspired Dexterity in Robotic Manipulation

Modeling and Human Performance in Manipulating Parallel Flexible Objects 77

(A) (B)

(C) (D)

(E) (F)
Fig. 5.4 Velocity profiles of the hand (top), the first bead (middle), and the second bead
(bottom), predicted by the minimum hand-jerk model (red line; light gray line in the
printed version) and the hand-force-change model (blue line; gray line in the printed
version), in comparison with the average of experimental data (dark green lines; dark
gray line in the printed version). The left column corresponds to the first subject and
the right one corresponds to the second subject.
summarized in Table 5.2. From the data reported in this table one concludes
that both the minimum hand-jerk and the minimum hand-force-change
models match the collected experimental data with a reasonable accuracy.
In addition to the RMS analysis, we compared the theoretical models by
a nondimensional quantity, the variance accounted for (VAF) by the model.
For the kth successful trial it is defined as
N
0 1
∗ ∗ 2
X
v k ðt i Þ v ðt i Þ v k + v
B C
B i¼1 C
VAF k ¼ 100 1 C , (5.58)
B
N
B C
2
X
@ A
f v k ðt i Þ v k g
i¼1