SomerBot: A Two-Legged Somersaulting Robotic Climber With Compliant Footpad

Abstract

Climbing capability is crucial for expanding the operational range of ground robots in inspection and exploration tasks within confined or hazardous spaces. We introduce SomerBot, a two-legged somersaulting robot designed for climbing flat and curved vertical surfaces. A key contribution is a 3D-printed compliant footpad with passive adhesion and tendon-driven detachment, reducing energy consumption compared to active adhesion techniques. The robot’s simple two-legged design minimizes fabrication complexity, weight, and power needs, which are critical for wall climbing. Optimized joint trajectory design ensures stable climbing by maintaining optimal surface contact. This article addresses several key issues: scaling of speed, payload, power, and weight with increasing motor torque, finding enhanced payload capacity without compromising speed. SomerBot’s structure, made using rapid prototyping techniques such as 3D printing and laser cutting, allows easy replication and customization. Experiments show its ability to transition between planes, overcome obstacles, and carry payloads at an average speed of 1.33 cm/s (0.12 body lengths/s). This work advances wall-climbing robots with energy-efficient adhesion and scalable design for complex climbing tasks.