3D humanoid robots: stability and Poincaré analysis
Control of Humanoid Robots

Consider an eight-body robot shown in figure 16. The robot has seven links between the bodies, some of which have more than one ddl. This is the case for the links at the ankle, which each possess two ddl of perpendicular and concurrent axes (angles q₁ and q₇ for the right ankle and angles q₆ and q₁₀ for the left ankle). This is also the case for the connections at the hips, which also each have two ddl of perpendicular and concurrent axes (angles q₃ and q₈ for the right hip and angles q₄ and q₉ for the left hip). The connection between pelvis and trunk is limited (for reasons of simplicity)...