This can be

4. 4

Torso Servoing

All of the walks presented thus far suffer from an unaesthetic "bobbing" of the torso.

readily observed in the continuous-time

RV

phase

diagrams

such

as

those

in

Figure

4.2.

Excursions in torso pitch of around 12 degrees are typical and they are quite apparent when

watching animations of the balanced walks. While these motions may in fact be desirable in some

cases, they tend to adversely affect the perceived quality of the motion when a realistic, natural

looking walk is the eventual goal.

10

5

0

-5

-10

10

5

-30

-25

-20

-15-10

meters

(b)

-5

0

(a)

0

-5

-10

-30

-25

-20

-15-10

meters

(d)

-5

0

(c)

Figure 4.15 - Trial results based on the walks of Figure 4.3 with the addition
of torso servoing to 5 degrees from world vertical. The biped
initially faces left (i.e. in the -x direction).
(a) - (b)F-L sampling
(c) - (d)L-F sampling