Robust spring mass model running for a physical bipedal robot

The analysis of the conceptual spring mass model for running reveals swing-leg placement policies that generate very robust locomotion in unobserved terrain with large changes in ground height. However, while this theoretical result suggests a potential for large improvements on the robustness of running machines, it has so far not been demonstrated on a physical robot. Here we address this implementation and verification step for a human-sized bipedal robot platform confined to a boom. We detail challenges and solutions for the implementation of the control approach and show that it leads to very robust running (ground changes ±20% of leg length) over unobserved ground in a high fidelity simulation of the robot platform. We also present initial tests on the actual robot hardware, which indicate the feasibility of the approach. If it can be generalized to 3D running, it could trigger running machines with largely improved robustness.