Bionic Design and Analysis of a Novel Quadruped Robot with a Multistage Buffer System

Large quadruped mammals, such as ruminants, have outstanding motion ability, including running and bounding. These advanced motion abilities are related to the buffer effect of their complicated musculoskeletal systems. However, the buffer effect of most bio-robots is not satisfactory owing to the simple design of their buffer systems. In this paper, a physiological analysis of the ruminant musculoskeletal system is presented to explain the intrinsic buffer mechanism of motion. Based on the physical buffer parts of the ruminant limbs, the corresponding bionic mappings were determined. These mappings were used to guide the mechanism design of the robot multistage buffer system. The multistage buffer system includes two main buffer mechanisms: the first stage and the second stage. The buffer mechanism analysis of the first stage and multiple stages is discussed in theory to compare the effects between the normal single buffer system and the novel multistage buffer system. Then, the detailed mechanical structure of the limbs was designed based on the limb mechanism design. To further verify the superior efficacy of the multistage buffer system, the corresponding walking simulation experiments were conducted after the virtual prototype of a quadruped robot with a novel limb was built completely. Both theoretical analysis and simulation experiments prove that the bionic robot design with the novel multistage buffer system achieves better motion performance than the traditional robot buffer design and can be regarded as the design template of the robot limb.