Optimal human-inspired ankle stiffness regulation for humanoid balancing control

In this work, a novel optimal human-inspired balancing control for the compliant humanoid, CoMAN, is introduced. The presented technique was motivated by the results of a human balance analysis. In particular, a human balancing experiment was carried out to investigate the torque-to-angular displacement profiles about the ankle joint. Experimental results obtained from this study, indicated that both the dorsiflexion and plantarflexion torques present an approximately exponential behavior. These findings served as an inspiration for the development of an optimal, nonlinear stiffness stabilizer, based on an ankle strategy. The balance stabilizer was experimentally validated on the compliant humanoid, CoMAN, demonstrating its balance inducing ability.