Experimental validation and simulation of a U-Shaped elastic beam robot for stable running locomotion

Abstract

Abstract This paper presents an innovative terrestrial robot employing a vibration-based locomotion system powered by a single DC motor with an eccentric rotating mass. The robot, composed of a U-shaped aluminum elastic beam and lightweight wooden feet, attains steady mobility by synchronizing torsional vibrations with centrifugal forces. Experimental and simulated analyses were performed at three angular velocities (ω 1  = 125.66 rad/s, ω 2  = 251.33 rad/s, ω 3  = 376.99 rad/s) to assess stability, deviation, velocity, and hopping performance. The results indicated that a rise in angular velocity significantly improved locomotion efficiency. At ω 1 , the robot attained an average body velocity of 85.46 mm/s and a hopping distance of 405.88 mm. At ω 2 , the velocity rose to 221.24 mm/s with a hopping distance of 418.24 mm, but ω 3 achieved optimal performance with a velocity of 265.49 mm/s and a hopping distance of 424.08 mm. Deviation responses settled within ± 2 mm after 2.5 s at ω 3 , in contrast to more pronounced oscillations at ω 1 . Simulation results largely aligned with experimental outcomes in hopping distance (error < 3 mm at ω 3 ) but routinely underestimated body velocity by 50–60%. The findings corroborate the suggested model for predicting vertical displacement, while underscoring the necessity for refinement to accurately capture horizontal velocity dynamics.