４足ロボットの生物規範型不整地適応動歩行―自立型「鉄犬２」による屋外歩行の実現―

Abstract

We describe efforts to induce a quadruped robot to walk with medium walking speed on irregular terrain based on biological concepts. We so far reported our experimental results of dynamic walking on terrains of medium degrees of irregularity with a planar quadruped robot “Patrush” and a three-dimensional quadruped robot “Tekkenl”. What we discussed and experimentally examined in those studies was how to design sensorimotor coordination system for adaptive dynamic walking. In this paper, we make the definition of biologically inspired control and summarize how to construct the neural system while introducing the nervous system of animals, relating studies on computational neuroscience and robotics, and our former studies using Patrush and Tekkenl. We propose the necessary conditions for stable dynamic walking on irregular terrain in general, and design the mechanical system and the neural system by comparing biological concepts with those necessary conditions described in physical terms. PD-controller at joints constructs the virtual spring-damper system as the visco-elasticity model of a muscle. The neural system model consists of a CPG (central pattern generator), reflexes and responses. We add several new reflexes and responses in order to satisfy the necessary conditions for stable dynamic walking in outdoor environment. We validate the effectiveness of the proposed neural system model control by making a self-contained quadruped robots called “Tekkenl” walk on natural ground. Consequently, we successfully propose the method to integrate CPGs and sensory feedback for adaptive dynamic walking of a quadruped.