Design and Experiment of a Small Legged Robot Operated by the Resonant Vibrations of Cantilever Beams

Abstract

A new driving method for small size legged robots was proposed and tested in this paper, in which the resonant vibrations of four flexible cantilever beams were used to generate the driving forces. The driving principle was elaborated as two sub principles, based on vertical bending vibrations and horizontal bending vibrations, respectively. According to the mode analysis and the harmonic analysis by the finite-element method, a prototype named Resbot was designed and fabricated. Experiments were carried out on two kinds of surfaces. The size of the Resbot was 99 mm $\times 148$ mm $\times 28$ mm, and its maximum speed was measured to be about 17.2 cm/s, which proved the feasibility of the proposed driving method for small legged robots. The relationship between the frequency of the driving force and the velocity of the Resbot demonstrated the availabilities of the two different driving sub-principles. The advantages of the proposed Resbot were that it was not only simple in structure for no intermediate transmission system, but also easy to be miniaturized, since there was no need to design the gaits; furthermore, it used an extremely simple control system.