1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135

93

IMAGE Imgs/thesis.final.w6183.gif

(a)


(b)


(c)

Figure 5.18 - Bent-over walking
(a) straight to bent transition
(b) walking bent-over
(c) bent to straight transition

Figure 5.18 shows the transitions into and out of the bent-over walk and a few steps of the bent-

over walk. Both transitions are performed over two steps, with a different scaling parameter used

for each intermediate step. The arm perturbations are included in order to make the biped's arms

appear to hang by its side in a "natural" position while the body is bent-over.

In retrospect, a

better approach would be to reduce

the

stiffness

and

damping

parameters

of

the

shoulder

actuators, letting physics determine a more appropriate arm position for the walk.

This would

require variable joint stiffness and damping parameters which are not currently supported.

5. 5. 3

Ducking

By combining the bent-knee and bent-over perturbations with an additional bend of the neck, it is

possible to form a relatively simple composite "ducking" perturbation which could potentially be

[CONVERTED BY MYRMIDON]