MOBIUS: A Multi-Modal Bipedal Robot that can Walk, Crawl, Climb, and Roll

TL;DR

The MOBIUS robot integrates walking, crawling, climbing, and rolling capabilities through a hybrid control system and high-level planning, enabling versatile terrain navigation and manipulation.

Contribution

This work introduces MOBIUS, a multi-modal bipedal robot with integrated locomotion and manipulation, demonstrating smooth transitions and robust interactions across diverse environments.

Findings

Successful gait transitions and dynamic climbing demonstrated in hardware tests.

MOBIUS can support full-body loads via pinch grasp.

High-level MIQCP planner effectively manages mode switching for stability and efficiency.

Abstract

This paper presents the MOBIUS platform, a bipedal robot capable of walking, crawling, climbing, and rolling. MOBIUS features four limbs, two 6-DoF arms with two-finger grippers for manipulation and climbing, and two 4-DoF legs for locomotion--enabling smooth transitions across diverse terrains without reconfiguration. A hybrid control architecture combines reinforcement learning for locomotion and force control for compliant contact interactions during manipulation. A high-level MIQCP planner autonomously selects locomotion modes to balance stability and energy efficiency. Hardware experiments demonstrate robust gait transitions, dynamic climbing, and full-body load support via pinch grasp. Overall, MOBIUS demonstrates the importance of tight integration between morphology, high-level planning, and control to enable mobile loco-manipulation and grasping, substantially expanding its interaction capabilities, workspace, and traversability.