Walking dynamics of a bipedal robot with impulsive actuation

Abstract

Impulsive actuation, which includes hip joint pulse torque and heel pulse thrust, is introduced to build a walking model of a bipedal robot on level ground in this study. The impulsive actuation configuration and the mechanism of stable walking motion are investigated. The existence and stability of period$-1$ and 2 gaits are investigated by means of the discrete map. The conditions for flip bifurcation and inverse flip bifurcation of period$-1$ gait are derived. The complex walking dynamics, such as period$-4$ gait, flip bifurcation and inverse flip bifurcation of period$-n(n=2,4)$ gait, and chaotic gait, are obtained by numerical simulations. By using period$-1$ gait, theoretical analysis is conducted on the energy consumption of applying pulse torque and constant torque to the hip joint under the same conditions. Numerical results show that the energy consumption of pulse torque is less than that of constant torque. The superiority and walking dynamics caused by impulsive actuation can provide theoretical reference for designing bipedal robots with stable and efficient walking.