The Experimental Study of the Influence of the Foot Articulated Structure on the Biped Robot Walking

Abstract: Purpose：By investigating the variation of the human walking gait kinematics with respect to the foot deformation constraint, prove that bionic design of feet are the necessity for biped robots to imitate human walking better in terms of flexibility, stability and efficiency. The results will be significant for future research and development of biped robots. Methods: A human being was assumed as a perfect biped robot which had ideal motion drive and control. The walking gait parameters of two healthy men with foot deformation unconstrained and constrained were tested respectively by the inertia motion capture suit, and then they were processed by programming and analyzed by comparison. Results: The data analysis showed that when subjects walked with foot deformation constrained, their angular displacements of lower limb joints generally increased, the curves of angular velocity and accelerations fluctuated in certain walking phases, the walking pace and stride length decreased obviously, the single support phase shortened while the double support phase lengthened. At the same time, subjects felt subjectively that their body motion was less flexible, the walking posture was difficult to control, and the walking stability was more strenuous to keep. Conclusion: Combining the logical analogies with the detailed experimentation results, it is inferred that biped robots with rigid feet will have to suffer awkward and unstable walking gait, heavier and strenuous steps, and lower energy efficiency while walking. The paper concludes the necessity of bionic design of the robot feet for improving the walking quality of the biped robots. The conclusion and the experiment data will be of significant value for future work of robot design and evaluation.