Structural design and motion simulation of a single-degree-of-freedom bouncing robot

Abstract Jumping, as an efficient three-dimensional motion, holds significant potential for applications such as adapting to complex terrains and exploring challenging environments. This study presents the development of a single-degree-of-freedom jumping robot inspired by the energy-efficient mechanism of frog hind limbs. The robot features a torsion-spring-driven five-bar structure that enables a “sustained energy storage - instantaneous energy re-lease” motion through the use of incomplete gears, which simplifies the mechanical design and reduces control complexity. The robot, with a horizontal size of 95 mm and a vertical size of 70 mm, can achieve a horizontal displacement of 400 mm and a vertical height of 180 mm, which equates to 4.21 times and 2.57 times its respective dimensions. In comparison to existing jumping robots, this design exhibits superior dynamic stability, as shown by the maximum pitch angle fluctuation of less than 25° and roll/yaw angle variations of under 0.002° during consecutive jumps.