Dynamical Analysis of Pace and Trot Gait Using a 3D Quadrupedal Model

Abstract

Quadrupeds selectively use pace gait or trot gait in the middle of their locomotion speed range. However, it remains unclear why they select pace or trot gait depending on their species or conditions. In this paper, we use a simple 3D quadrupedal model to find periodic solutions corresponding to the motions of pace and trot gait. Using physical parameters of dogs, we compared obtained solutions of pace and trot using obtained touchdown angles of legs and three criteria: stability, energy efficiency, and maximum ground reaction force(GRF). From the results, we found that solutions of pace and trot had different touchdown angles of legs. In addition, we also found that regardless of locomotion speed, the solutions of pace were more stable and had smaller GRF than those of trot. On the other hand, the solutions of trot were more efficient motions than those of pace. These results can partially explain the reasons of selecting pace and trot gait by animals.