A novel bio-inspired kangaroo leg structure for low-frequency vibration isolation

Abstract

Inspired by the vibration mitigation effect of kangaroo's legs, a novel bio-inspired kangaroo leg structure (BKLS) is proposed for low-frequency vibration isolation. The BKLS is composed of two main rods with different lengths (simulating the calf bone and thigh bone), two linear springs (simulating the internal and external muscles) and two auxiliary rods. The dynamic model is established based on the Lagrange principle to describe the nonlinear effects of BKLS, which are mainly contributed by the internal and external springs and the rotary joints. Experiments were carried out to verify the theoretical predictions and demonstrate that the proposed BKLS indeed possess superior low-frequency isolation performance without sacrificing the carrying capacity, which can effectively suppress vibration with frequencies higher than 1.06 Hz. Regardless of the isolation mass and the excitation conditions, the vibration isolation performance can be significantly improved by selecting appropriate structural parameters. The innovative and simple BKLS provides an effective method for low-frequency vibration isolation.