A Quadruped Crawling Robot Operated by Elliptical Vibrations of Cantilever Legs

In this article, a quadruped robot, consisting of a main body, four cantilever legs, four eccentric wheel vibration motors, a battery, and a circuit control module, is proposed and tested. Vibration motors are used to motivate the cantilever legs to form elliptical trajectories at the feet. Forward, backward, and turning movements could be accomplished by the cooperations of the four cantilever legs, and the driving force or torque for the movements was generated from the frictional forces between the feet and the ground. A prototype is designed, fabricated, and tested after the mode analysis and the harmonic analysis by the finite-element method. The size of the robot is 72 × 76 × 35 mm, and its weight was only 61.8 g. The test results demonstrate that the forward, backward, steering, and in situ steering motions of the robot are achieved on three contact surfaces: terrazzo, wood, and glass. The robot achieve a maximum speed of 206 mm/s and the maximum load capacity of 110 g on the terrazzo surface. The proposed robot show the superiorities of high motion velocity without the transmission system, multiple movements, and onboard power; it also has certain environmental adaptability, load capacity, and obstacle crossing ability.