MEVIUS2:

Abstract

Various quadruped robots have been developed to date, and thanks to reinforcement learning, they are now capable of traversing diverse types of rough terrain. In parallel, there is a growing trend of releasing these robot designs as open-source, enabling researchers to freely build and modify robots themselves. However, most existing open-source quadruped robots have been designed with 3D printing in mind, resulting in structurally fragile systems that do not scale well in size, leading to the construction of relatively small robots. Although a few open-source quadruped robots constructed with metal components exist, they still tend to be small in size and lack multimodal sensors for perception, making them less practical. In this study, we developed MEVIUS2, an open-source quadruped robot with a size comparable to Boston Dynamics' Spot, whose structural components can all be ordered through e-commerce services. By leveraging sheet metal welding and metal machining, we achieved a large, highly durable body structure while reducing the number of individual parts. Furthermore, by integrating sensors such as LiDARs and a high dynamic range camera, the robot is capable of detailed perception of its surroundings, making it more practical than previous open-source quadruped robots. We experimentally validated that MEVIUS2 can traverse various types of rough terrain and demonstrated its environmental perception capabilities. All hardware, software, and training environments can be obtained from Supplementary Materials or https://github.com/haraduka/mevius2.

Design Overview

MEVIUS2 consists of 16 unique metal parts (excluding mirrored parts), including machined aluminum components and welded sheet-metal structures. The Base-Link integrates leg, sensor, and circuit mount points into a single welded component to reduce part count and improve rigidity.

Metal Parts and Sheet Metal Welding

The robot uses 11 machined A7075 parts and 5 A5052 sheet-metal parts. Three parts (Base-Link, Hip-Link, and Lidar-Cover) are fabricated by sheet metal welding. This structure is key to scaling open-source quadrupeds to practical size and strength.

Multimodal Sensor Configuration

MEVIUS2 equips two Livox Mid-360 LiDAR sensors and one Tier IV C1 HDR RGB camera. The sensor placement provides broad geometric and visual coverage for perception and elevation mapping.

Circuit and Control Architecture

The platform uses 12 Robstride03 motors connected through two CAN-USB interfaces.

Policies are trained in IsaacGym, validated in MuJoCo with shared Python scripts, and then deployed to real hardware.

Experiments

Hardware experiments and perception demos on MEVIUS2.

Bibtex

@article{kawaharazuka2026mevius2,
  title={{MEVIUS2: Practical Open-Source Quadruped Robot with Sheet Metal Welding and Multimodal Perception}},
  author={Kento Kawaharazuka and Keita Yoneda and Shintaro Inoue and Temma Suzuki and Jun Oda and Kei Okada},
  journal={IEEE Robotics and Automation Practice},
  year={2026},
}