Investigation of Interactions between Embodiment and its Controller Using a Passive Dynamic Walking Robot

Over the past decade it has been widely recognized that not only the controllers implemented but also their embodiment, such as robots’ body, significantly influence the emergence of intelligence. In spite of its importance, still few studies have explicitly investigated this mutual interaction. In light of these facts, in this article, the interaction between controllers and their embodiments is investigated. To do so, a synthetic approach is employed. More specifically, construction of a locomotion controller that enables a passive dynamic walking (PDW) robot to walk on a flat terrain is taken as a practical example. In this study, so-called staged evolution is conducted for this purpose. First, body parameters (e.g. mass, length) of a biped robot are evolved in order to elicit PDW. After obtaining acceptable embodiments, their CPG (Central Pattern Generator)-based controllers are evolved. Simulations have been carried out and the results have shown that “appropriate” embodiments allow us to significantly increase the efficiency of developing their controllers.