A simple extension of inverted pendulum template to explain features of slow walking✰.

Published

Journal Article

Locomotion involves complex interactions between an organism and its environment. Despite these complex interactions, many characteristics of the motion of an animal's center of mass (COM) can be modeled using simple mechanical models such as inverted pendulum (IP) and spring-loaded inverted pendulum (SLIP) which employ a single effective leg to model an animal's COM. However, because these models are simple, they also have many limitations. We show that one limitation of IP and SLIP and many other simple mechanical models of locomotion is that they cannot model many observed features of locomotion at slow speeds. This limitation is due to the fact that the gravitational force is too strong, and, if unopposed, compels the animal to complete its stance in a relatively short time. We propose a new model, AS-IP (Angular Spring modulated Inverted Pendulum), in which the body is attached to the leg using springs which resist the leg's movement away from the vertical plane, and thus provides a means to model forces that effectively counter gravity. We show that AS-IP provides a mechanism by which an animal can tune its stance duration, and provide evidence that AS-IP is an excellent model for the motion of a fly's COM. More generally, we conclude that combining AS-IP with SLIP will greatly expand our ability to model legged locomotion over a range of speeds.

Full Text

Duke Authors

Cited Authors

  • Biswas, T; Rao, S; Bhandawat, V

Published Date

  • November 2018

Published In

Volume / Issue

  • 457 /

Start / End Page

  • 112 - 123

PubMed ID

  • 30138629

Pubmed Central ID

  • 30138629

Electronic International Standard Serial Number (EISSN)

  • 1095-8541

International Standard Serial Number (ISSN)

  • 0022-5193

Digital Object Identifier (DOI)

  • 10.1016/j.jtbi.2018.08.027

Language

  • eng