A Novel Omnidirectional Wheel Based on Reuleaux-Triangles

This paper discusses the mechanical design and simulation of a novel omnidirectional wheel based on Reuleaux-triangles. The main feature of our omniwheel is that the point of contact of the wheel with the floor is always kept at the same distance from the center of rotation by mechanical means. This produces smooth translational movement on a flat surface, even when the profile of the complete wheel assembly has gaps between the passive rollers. The grip of the wheel with the floor is also improved. The design described in this paper is ideal for hard surfaces, and can be scaled to fit small or large vehicles. This is the first design for an omnidirectional wheel without circular profile, yet capable of rolling smoothly on a hard surface. 1 Motivation and Reuleaux triangles It has been thought for many years, that the only way of providing a smooth rolling effect when using omnidirectional wheels with gaps between rollers is: a) by stacking two wheels on the same axis, producing a combined circular profile; b) by using several synchronized wheels which combine in order to support the vehicle keeping the distance to the floor constant; or c) by using spheres or quasispheres as wheels. There is a fourth alternative, which is to design omniwheels with a circular profile, in which the gaps are almost closed by using two kinds of rollers alternatively, as in [3]. Long and short rollers alternate on the periphery of the wheel. In this paper we show for the first time that it is possible to build an omnidirectional wheel with gaps between the transversal rollers, that is without circular profile, which is nevertheless able to drive smoothly. A so-called Reuleaux triangle (named after the German engineer Franz Reuleaux, who was a professor of mechanical engineering at the Technical University of 1 The very first omnidirectional wheel was patented in 1919 by J. Grabowiecki in the US [1]. Bengt Ilon patented another in 1973 [2].