The designs and motions of a shoulder structure with a spherical thorax, scapulas and collarbones for humanoid “Kojiro”

Humanoid robots are still in a process of the evolution. We are trying to develop a next-generation which have safety, flexibility and multiplicity of uses. A shoulder structure is one of the keystone, because it controls arms and end effectors and it have direct contact with humans and daily life environments. We have designed new shoulder structure following the scapula-collarbone structure for a muscle-driven humanoid robot named ldquoKojirordquo (Fig. 1)[1]. We consider that the scapula-collarbone structures have the following merits, 1)wide range of movement, 2)flexible shoulder like humans, 3)safety from the driving system, 4)allowing space for a lot of parts inside the thorax. The shoulder structure is consisted of scapula, collarbone, upper-arm and thorax. We have devised the spherical shape thorax and scapula structure which realizes desired scapula motions. In this paper, we describe the design process and operation test of the shoulder structure.