Robust Spring Mass Model Running for a Physical Bipedal Robot

Abstract

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.