Legged Rescue Robotic Leg Design

University of California, San Diego

Mechanical and Aerospace Engineering 

MAE 156B: Senior Design Project

Currently, the use of robots to physically move people is limited due to safety concerns. In medical settings, robots used for rehabilitation and assistive technology typically rely on human intervention and physician oversight to ensure safe operation. Even with these precautions, injury is a major risk, highlighting the challenges inherent in designing robots that can safely interact with the human body.

In disaster scenarios and emergency medical situations, the ability to rapidly locate and extract injured or unconscious persons is critical. These environments can present challenging terrain conditions with debris, uneven surfaces, and obstacles that conventional wheeled robots struggle to navigate. ARClab envisions addressing these challenges through a hexapod robotic platform capable of navigating through such conditions to reach casualties and safely transport them to safety.

This rescue robot faces the challenge of requiring the ability to accommodate two opposing operational requirements. It must be capable of traversing uneven terrain at approximately human walking speed (1.2-1.4 m/s) while also being powerful enough to transport a 90 kg person to safety. This creates conflicting design requirements as high speeds typically require configurations providing longer strides with less mechanical advantage, while high torque output requires configurations providing higher mechanical advantage at the sacrifice of speed and stride length. 

ARClab has not previously researched legged robotics, and has therefore sponsored this project to develop its infrastructure and conduct initial research into the subject. The primary focus of this project is to develop a transforming robotic leg mechanism, as well as a test bed to enable the evaluation of the leg mechanism’s ability of the leg mechanism to switch between these two operational modes to enable the hexapod platform to efficiently perform both rapid navigation and casualty extraction without compromising either capability.