Models of benthic bipedalism

Abstract

Walking is a common bipedal and quadrupedal gait and is often associated with terrestrial and aquatic organisms. Inspired by recent evidence of the neural underpinnings of primitive aquatic walking in the little skate Leucoraja erinacea , we introduce a theoretical model of aquatic walking that reveals robust and efficient gaits with modest requirements for body morphology and control. The model predicts undulatory behaviour of the system body with a regular foot placement pattern, which is also observed in the animal, and additionally predicts the existence of gait bistability between two states, one with a large energetic cost for locomotion and another associated with almost no energetic cost. We show that these can be discovered using a simple reinforcement learning scheme. To test these theoretical frameworks, we built a bipedal robot and show that its behaviours are similar to those of our minimal model: its gait is also periodic and exhibits bistability, with a low efficiency mode separated from a high efficiency mode by a ‘jump’ transition. Overall, our study highlights the physical constraints on the evolution of walking and provides a guide for the design of efficient biomimetic robots.

On the Timescales of Embodied Intelligence for Autonomous Adaptive Systems

“…Such systems have inspired energy-efficient robot designs that can walk efficiently on flat ground (51). Similar arguments of scale matching in locomotion can be made for brachiation (52), benthic locomotion (53), and swimming (54).…”

Bootstrapping Virtual Bipedal Walkers with Robotics Scaffolded Learning

“…Pedagogical applications have actively used scaffolding to bootstrap knowledge ( Quarles et al, 2009 ; Al Mamun et al, 2020 ), and some researchers tried to understand its associations with human locomotion: the ontogenetic development ( Lungarella et al, 2003 ) of bipedal walking in human infants ( Susa, 1981 ), and the mechanism of acquiring general motor skills and of human walking ( Okamoto, 1985 ; Thelen et al, 1991 ). Besides, reaching bipedal locomotion ( Wahde and Pettersson, 2002 ; Vukobratovic et al, 2012 ; Giardina and Mahadevan, 2021 ) during early childhood requires individuals to be strong enough to support their weight, stable enough to resist an ever oscillating center of gravity, and to move in a state of dynamic balance when the body alternates between the double support and the single support ( Bril and Brenière, 1993 ; Owaki et al, 2013 ; Swan et al, 2020 ). Along these lines, the work from Hase and Yamazaki (1998) simulated a supported infant walking by applying linear springs and dampers to a bipedal walking model, which was controlled by a rhythm-generation mechanism called central pattern generator ( Grillner and Wallen, 1985 ; Reil and Husbands, 2002 ).…”