KLEIYN : A Quadruped Robot with an Active Waist for Both Locomotion and Wall Climbing

TL;DR

This paper introduces KLEIYN, a quadruped robot with an active waist joint, capable of wall climbing using reinforcement learning and a novel curriculum learning method, achieving significantly faster and more stable vertical locomotion.

Contribution

The study presents a new quadruped robot with an active waist joint and a Contact-Guided Curriculum Learning method for efficient wall climbing, expanding locomotion capabilities in rough terrains.

Findings

KLEIYN climbed walls 800-1000mm wide at 150mm/s, 50 times faster than previous robots.

The waist joint improves climbing stability and narrow wall tracking.

Contact-Guided Curriculum Learning facilitates vertical motion learning.

Abstract

In recent years, advancements in hardware have enabled quadruped robots to operate with high power and speed, while robust locomotion control using reinforcement learning (RL) has also been realized. As a result, expectations are rising for the automation of tasks such as material transport and exploration in unknown environments. However, autonomous locomotion in rough terrains with significant height variations requires vertical movement, and robots capable of performing such movements stably, along with their control methods, have not yet been fully established. In this study, we developed the quadruped robot KLEIYN, which features a waist joint, and aimed to expand quadruped locomotion by enabling chimney climbing through RL. To facilitate the learning of vertical motion, we introduced Contact-Guided Curriculum Learning (CGCL). As a result, KLEIYN successfully climbed walls ranging from 800 mm to 1000 mm in width at an average speed of 150 mm/s, 50 times faster than conventional robots. Furthermore, we demonstrated that the introduction of a waist joint improves climbing performance, particularly enhancing tracking ability on narrow walls.