Gait analysis and efficiency improvement of passive dynamic walking of combined rimless wheel with wobbling mass

Abstract

It was clarified that speeding-up of passive dynamic walking (PDW) of a combined rimless wheel (CRW) can be achieved by adjustment of the phase difference between the fore and rear legs. We discussed the mechanism from the viewpoint of overcoming potential barrier, and showed that the trajectory of the whole center of mass (CoM) is significantly flattened by choosing the phase difference. This paper investigates the potentiality of speeding-up the CRW without having the phase difference but by using a passive wobbling mass that vibrates up and down in the body in expectation of flattening the whole CoM trajectory. We show that the walking speed is increased by the effect of the wobbling mass and that a transition from anti-phase to in-phase oscillation arises with the increase of the elasticity. We also show nonlinear characteristics such a high sensitivity to initial conditions and hysteresis phenomenon. Furthermore, the validity of the simulation results is verified using an experimental CRW machine.

Soft tissue vibration: a biologically-inspired mechanism for stabilizing bipedal locomotion

“…Efficient and stable walking dynamics are highly desirable in the field of bipedal robotic walking. It has been shown that wobbling mass motion can make robotic walkers ambulate at faster or slower speeds by tuning the spring-damper parameters of the wobbling mass (e.g., Tanaka et al 2012, Hanazawa et al 2013. However, our results indicate that passive wobbling mass motion can make a rigid passive dynamic walker ambulate faster and with greater dynamic stability.…”

Wobbling mass effects for a walking robot with inerters

“…Studies of the wobbling mass effect improving energy efficiency and walking speed of limit cycle walkers have been conducted. [11] [12] In this paper, we will show that the wobbling mass motion can also improve the walking properties for walking robots with † Mamoru Watanabe is the presenter of this paper. ankle impedances including inerters by numerical simulations.…”

Robust walking of biped robot on uneven terrain using effect of wobbling mass

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