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Robot in Society: A Question of Interface 23

incorporate hair, teeth, silicone skin, and a large number of control points (Hara, 1998). Each
control point maps to a facial action unit of a human face. The facial action units characterize
how each facial muscle (or combination of facial muscles) adjust the skin and facial features
to produce human expressions and facial movements (Ekman & Friesen, 1982). Using a
camera mounted in the left eyeball, the robot can recognize and produce a predefined set
of emotive facial expressions (corresponding to anger, fear, disgust, happiness, sorrow, and
surprise). A number of simpler expressive faces have been developed at Waseda University,
one of which can adjust its amount of eye-opening and neck posture in response to light
intensity (Takanobu et al., 1999).
The number of humanoid robotic projects under way is growing, with a particularly
strong program in Japan (see figure 2.4). Some humanoid efforts focus on more traditional
challenges of robot control. Honda’s P3 is a bipedal walker with an impressive human-
like gait (Hirai, 1998). Another full-bodied (but non-locomotory) humanoid is at ATR
(Schaal, 1999). Here, the focus has been on arm control and in integrating arm control
with vision to mimic the gestures and tasks demonstrated by a human. There are several
upper-torso humanoid robots. NASA is developing a humanoid robot called Robonaut
that works with astronauts to perform a variety of tasks while in orbit, such as carrying
out repairs on the external surface of the space shuttle (Ambrose et al., 1999). One of
the most well-known humanoid robots is Cog, under development at the MIT Artificial
Intelligence Lab (Brooks et al., 1999). Cog is a general-purpose humanoid platform used
to explore theories and models of intelligent behavior and learning, both physical and
social.

Figure 2.4
Some examples of humanoid robots. To the left is Cog, developed at the MIT AI Lab. The center picture shows
Honda’s bipedal walking robot, P3. The right picture shows NASA’s Robonaut.