Passive compliant foot design for improved micororobotic mobility on rough terrains

摘要

To deploy robots outside of laboratory environments, they must be able to locomote on natural, unstructured terrain. While perception and control strategies for terrain navigation and obstacle avoidance have been developed for human-scale robots, microrobots are often too small to carry the sensors, computing power, and energy required to implement such techniques. Instead, this work presents passive foot designs for improving open-loop, quasi-static locomotion of a 1.6 g, 45 mm quadruped robot over rough terrains. The feet were evaluated by tracking the distance travelled on an uneven terrain of progressively increasing feature heights. Our insect tarsi inspired rigid foot designs improved performance somewhat, and by adding passive compliance via a viscoelastic hinge on the heel and toe, we increased the distance travelled by 168% over the original design. By exploring the design space of foot geometries and compliance, this work lays the foundation for understanding how passive foot design facilitates locomotion over uneven terrains.