MEVIUS2: Practical Open-Source Quadruped Robot with Sheet Metal Welding and Multimodal Perception

Kento Kawaharazuka; Keita Yoneda; Shintaro Inoue; Temma Suzuki; Jun Oda; Kei Okada

cs.ROMar 23, 2026

MEVIUS2: Practical Open-Source Quadruped Robot with Sheet Metal Welding and Multimodal Perception

Authors: Kento Kawaharazuka, Keita Yoneda, Shintaro Inoue, Temma Suzuki, Jun Oda, Kei Okada

Organizations: The authors are with the Department of Mechano-Informatics, Graduate School of Information Science and Technology, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo, 113-8656, Japan.

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.

Figures & tables

Fig. 1: MEVIUS2 – Practical open-source quadruped robot with sheet metal welding and multimodal perception, developed in this study.

Fig. 2: Design overview of MEVIUS2: excluding mirrored parts, the robot consists of 16 unique metal components, three of which are fabricated using sheet metal welding to achieve complex and large geometries as single integrated parts.

Fig. 3: All metal components used in MEVIUS2.

Fig. 4: Details of sheet metal welding for the Base-Link and Hip-Link. The welded sections are highlighted in red.

Fig. 5: The sensor configuration of MEVIUS2.

Name	Weight	Leg Length *1	Materials	Open/Closed (CAD)	Off-the-shelf (Circuit)	Maximum Torque	Cost (USD)	Perception
Mini Cheetah [ 2 ]	9.0 kg	0.20 m	Metal	Closed	No	17 Nm	-	-
ANYMAL [ 3 ]	30.0 kg	0.25 m	Metal	Closed	No	40 Nm	150k	LiDAR/Camera
Spot [ 23 ]	33.8 kg	0.34 m	Metal	Closed	No	85 Nm *2	75k	LiDAR/Camera
Solo-12 [ 12 ]	2.5 kg	0.16 m	Plastic	Open	No	2.5 Nm	12k	-
PAWDQ [ 13 ]	12.7 kg	0.22 m	Plastic	Open	Yes	21 Nm	8k	Camera
MEVIUS [ 22 ]	15.5 kg	0.25 m	Metal / POTICON	Open	Yes	25 Nm	12k	-

TABLE I: Comparison between existing quadruped robots and MEVIUS2

Fig. 6: Circuit configuration of MEVIUS2: servo motors are connected to the PC via two CAN-USB interfaces, and the system is equipped with a wireless emergency stop, power relay, diode, LiDAR/IMU, and RGB camera.

Fig. 7: Control system of MEVIUS2: policies trained in IsaacGym are verified in MuJoCo and deployed to the actual hardware using common Python scripts.

Fig. 8: Walking experiments in various environments: (A) concrete, grass, and soil; (B) stairs; (C) steep slopes; (D) slippery stairs after rainfall; and (E) indoor settings.

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