Autonomous speed adaptation by a muscle-driven hind leg robot modeled on a cat without intervention from brain. (22nd September 2021)

• Record Type: Journal Article
• Authors: Fukuoka, Yasuhiro; Habu, Yasushi; Inoue, Kouta; Ogura, Satoshi; Mori, Yoshikazu
• Is Part Of: International journal of advanced robotic systems. Volume 18:Number 5(2021)
• Publication Date: 2021-09-22
• Subjects: Cat-like muscle-driven hind leg robot -- walking and running -- autonomous speed adaptation -- two-level central pattern generators; Robotics -- Periodicals; Robotics; Periodicals; 629.892
• DOI: 10.1177/17298814211044936
• Languages: English
• ISSNs: 1729-8806

Abstract

This study aims to design a nervous system model to drive the realistic muscle-driven legs for the locomotion of a quadruped robot. We evaluate our proposed nervous system model with a hind leg simulated model and robot. We apply a two-level central pattern generator for each leg, which generates locomotion rhythms and reproduces cat-like leg trajectories by driving different sets of the muscles at any timing during one cycle of moving the leg. The central pattern generator receives sensory feedback from leg loading. A cat simulated model and a robot with two hind legs, each with three joints driven by six muscle models, are controlled by our nervous system model. Even though their hind legs are forced backward at a wide range of speeds, they can adapt to the speed variation by autonomously adjusting its stride and cyclic duration without changing any parameters or receiving any descending inputs. In addition to the autonomous speed adaptation, the cat hind leg robot switched from a trot-like gait to a gallop-like gait while speeding up. These features can be observed in existing animal locomotion tests. These results demonstrate that our nervous system is useful as a valid and practical legged locomotion controller.