18th annual conference on manual control.pdf - Acgsc.org

Data for Group 2 have been extensively analyzed and are shown in Figure 2
together with their best fit line. The equation for this llne averaged across
subjects is
S = 36.31 1I"06
where
S = perceived "top heaviness"
I = mass moment of inertia
There was surprisingly little variation among subjects.
subject was 1.00, 0.76, 1.2, 1.22.
The exponent for each
DISCUSSION
Under these experimental conditions the relationship between mass moment
of inertia and sensation was approximately linear. The power function 1.06
fits within the range of exponents found in scaling experiments for other
senses: length 1.0, pain 3.45, loudness 0.67, heaviness 1.45, brightness 0.33
to 1.0, angular accelertion 1.4, cold 1.0, and warmth 1.6 (2).
The sensation
of mass moment of inertia may be perceived to increase less rapidly than for
heaviness, tentatively suggesting that increasing the heaviness or mass of a
tool asseiated with a manually controlled operation may be more noticeable than
increasingthe
mass moment of inertia.
These results will be useful in designing handling systems where trade-off
decisions might have to be made concerning the relative effects on perception
and task performance of these two properties and in designing further studies
in which
these two properties may be studied simultaneously.
Future plans include the following:
I. Complete analysis of all present data.
2. Perceptual scaling of mass and of mass moment of inertia in
larger reach envelopes.
3. Cross-modality scaling where subjects will be asked to equate the
perceived mass moment of inertia of one set of stimuli with the
perceived mass of a second set.
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