Predictive Dynamics - Human Motion Simulation: Predictive Dynamics - page 105

Table 5.1 Major Joint Angle Limits a,b

Joints Joint Angle Limits (Degree)

Lower Limit Upper Limit

Ankle (dorsi/plantar) 20 54.5

2

Knee (extension/flexion) 7 138

Hip (flexion/extension) 102 41

2

Hip (abduct/adduct) 46 34

2

Hip (external/internal) 49 32

2

Spine (tilt) 11 11

2

Spine (bend) 9.5 21

2

Spine (rotate) 13.5 13.5

2

Shoulder (aft/fore) 19 111

2

Shoulder (adduct/abduct) 23 123.5

2

a Zero joint angles correspond to home configuration as depicted in Figure 7.2.
b Joint coupling motions are not considered.

y

x

z

FIGURE 5.6
Foot ground penetration conditions.

5.7.1.3 Ground penetration
Walking is characterized with unilateral contact between the foot and ground as
shown in Figure 5.6 . While the foot contacts the ground, the height and velocity
of contacting points (circles) are zero. In contrast, the height of other points
(triangles) on the foot is greater than zero.
Therefore, the ground penetration constraints are formulated as follows:

y i ðtÞ 5 0 ; x i ðtÞ 5 _ 0 ; y i ðtÞ 5 _ 0 ; z i ðtÞ 5 _ 0 ; i A Ω

(5.23)

y i ðtÞ . 0 ; i 2 Ω; 0 # t # T

where Ω is the set of contacting points as illustrated in Figure 5.6 .