Robust and directive quadruped locomotion on rough terrain without requiring sensing and actuation

Abstract

Quadrupedal animals adaptively change their trunk posture to avoid falling down and to facilitate directive locomotion even on rough terrain. This paper focuses on an animal-like trunk mechanism that has passive viscoelastic joints. The effect of the trunk mechanism is observed by changing the elasticity and configuration of the joints. Simulation results show that the success rate of the locomotion of a robot equipped with the trunk mechanism on rough terrain is higher than that of a robot equipped with a rigid body. In addition, the distribution of the success rate changes according to the elastic coefficient, number of joints, and configuration of the joints. These results suggest a design principle for the trunk mechanism of a quadruped robot to obtain robust and directive locomotion without requiring sensors and actuators.