Control of a Four-Forked steering Walker—Design of virtual mechanical elements based on desired motions

Abstract

This paper presents a new undulatory locomotor, a four-forked steering walker, and introduces a quite new design methodology of virtual mechanical elements which facilitates to achieve desired motions. The four-forked steering walker transforms periodic changes in shape into movement as if it performs roller skating. The virtual mechanical elements are originally defined solely for conversion of kinematical equations of the locomotor into a chained form. It is shown in this paper that such definition has another aspect in which the virtual mechanical elements enabling the conversion can be also designed according to desired motions. Specifically, the base of the locomotor can be replaced with a virtual base and its shape and locations of the virtual mechanical elements on the virtual base can be modified according to path-following and gyrating motions. The validity of the design methodology is verified experimentally.