Design of HyQ – a hydraulically and electrically actuated quadruped robot

TLDR

Hydraulic actuation enables the robot to perform powerful and dynamic motions that are difficult for purely electrically actuated robots. This paper details the design and specifications of HyQ, including the mechanical layout of its four articulated legs, torso frame, and hydraulic power system. HyQ is a 1‑m tall, ~90‑kg quadruped with 12 torque‑controlled joints powered by a combination of hydraulic and electric actuators. HyQ was successfully built and demonstrated running, jumping, and rough‑terrain navigation, with initial walking experiments and prototype‑leg tests confirming its performance.

Abstract

A new versatile hydraulically powered quadruped robot ( HyQ) has been developed to serve as a platform to study not only highly dynamic motions, such as running and jumping, but also careful navigation over very rough terrain. HyQ stands 1 m tall, weighs roughly 90 kg, and features 12 torque-controlled joints powered by a combination of hydraulic and electric actuators. The hydraulic actuation permits the robot to perform powerful and dynamic motions that are hard to achieve with more traditional electrically actuated robots. This paper describes design and specifications of the robot and presents details on the hardware of the quadruped platform, such as the mechanical design of the four articulated legs and of the torso frame, and the configuration of the hydraulic power system. Results from the first walking experiments are presented, along with test studies using a previously built prototype leg.