Humanoid trajectory generation: an iterative approach based on movement and angular momentum criteria

Recently, data from human walking suggest that angular momentum at the center of mass (CM) is highly regulated throughout the gait cycles. In this paper, we propose a humanoid robot trajectory generation that minimizes angular momentum at CM while maintaining balance based on the moment criterion. This moment criterion is equivalent to the zero moment point (ZMP) stability criterion. Because of the extensive computational requirement of the problem, we first utilize spline interpolation of the desired movement snapshots to generate an initial humanoid robot trajectory, and then an iterative adaptation of the humanoid robot trajectory to maintain angular momentum within the desired boundary subject to the ZMP balance constraint is investigated and derived. Numerical simulation was conducted to verify the validity of the proposed trajectory generation method.