This project, conducted under the guidance of UC San Diego’s Advanced Robotics and Controls Lab (ARClab) and funded by the Department of Defense through the Telemedicine and Advanced Technology Research Center (TATRC), aimed to develop a reconfigurable robotic leg for a future hexapod search-and-rescue platform. The goal was to enable the leg to transition between two mechanical configurations—one optimized for high-speed traversal and the other for high-force, load-bearing operation—while supporting the chassis, two robotic arms, and a 90 kg human payload.

To meet these functional requirements, the team selected a 5-bar pantograph linkage architecture. This design offers planar kinematics, high stiffness, and the ability to shift mechanical advantage by adjusting a single ground link actuator. Symmetry and simplicity of control also made the pantograph favorable compared to alternative geometries.

A test bed was constructed to evaluate leg performance under both static and dynamic conditions. Key features included linear bearing rails for constrained actuation, a counterweight system to offset the test bed’s own mass, and a force-torque sensor mounted beneath the foot for measuring ground reaction forces. This modular setup enabled rapid testing of various link configurations and motion profiles.