Chaos and Bifurcation Control of Torque-Stiffness-Controlled Dynamic Bipedal Walking

This paper focuses on chaos control of a seven-link torque-stiffness-controlled dynamic walking model, actuated by a bio-inspired control system. The biped consists of compliant hip, knee and ankle joints and flat feet. We employed Ott-Grebogi-Yorke and delayed feedback control methods, responsible for small errors around the equilibrium solution and large errors far away, respectively. In simulation, we study the stabilization of bifurcations and chaotic behaviors under diverse actuation parameters, and the convergence speed to 1-period gaits. The results of this paper may provide insights into motion control of dynamic walking robots and principles of human locomotion.