Active viscoelastic-legged rimless wheel with upper body and its adaptability to irregular terrain

It was clarified that a rimless wheel with viscoelastic legs generates stable passive-dynamic gaits including measurable period of double-limb support motion. This paper then investigates the effect of the leg viscoelasticity on the adaptation ability to irregular terrain through numerical simulations and experiments. We introduce the model of an active viscoelastic-legged rimless wheel (VRW) that consists of eight identical viscoelastic legs and an upper body for analysis. We then develop the mathematical model and numerically examine the adaptation ability to irregular terrain. In this paper, we consider the two situations; one is overcoming steps and the other is sustaining stable walking on a flexible surface. The adaptability of the active VRW is compared with that of the rigid-legged model.