SCALER: A Tough Versatile Quadruped Free-Climber Robot

TL;DR

SCALER is a versatile quadruped robot capable of free-climbing on various surfaces and ground locomotion, combining high mobility, payload capacity, and innovative gait and gripping mechanisms for practical use.

Contribution

The paper presents SCALER, a novel quadruped robot with high degrees of freedom, versatile climbing and ground mobility, and new climbing gait and gripper design, advancing robotic mobility capabilities.

Findings

Achieves 0.56 m/s ground speed and 0.35 m/min climbing speed.

Supports payload up to 233% of its weight on ground.

Successfully grasps convex and non-convex objects with GOAT gripper.

Abstract

This paper introduces SCALER, a quadrupedal robot that demonstrates climbing on bouldering walls, overhangs, ceilings and trotting on the ground. SCALER is one of the first high-degrees of freedom four-limbed robots that can free-climb under the Earth's gravity and one of the most mechanically efficient quadrupeds on the ground. Where other state-of-the-art climbers specialize in climbing, SCALER promises practical free-climbing with payload \textit{and} ground locomotion, which realizes true versatile mobility. A new climbing gait, SKATE gait, increases the payload by utilizing the SCALER body linkage mechanism. SCALER achieves a maximum normalized locomotion speed of $1.87$ /s, or $0.56$ m/s on the ground and $1.0$ /min, or $0.35$ m/min in bouldering wall climbing. Payload capacity reaches $233$ % of the SCALER weight on the ground and $35$ % on the vertical wall. Our GOAT gripper, a mechanically adaptable underactuated two-finger gripper, successfully grasps convex and non-convex objects and supports SCALER.