Comparing the Locomotion Dynamics of the Cockroach and a Shape Deposition Manufactured Biomimetic Hexapod

We describe the locomotion dynamics of a biomimetic robot and compare them with those of its exemplar: the cockroach. The robot is a small (0.275kg) hexapod created using a layered manufacturing technique that allows us to tailor the compliance and damping of the limbs to achieve passive stabilization similar to that observed in insects. The robot runs at over 3 body-lengths per second (55 cm/s) and easily traverses hip-height obstacles. However, high-speed video and force data reveal differences between the robot’s locomotion dynamics and the inverted spring-pendulum model that characterizes most running animals, including cockroaches. Closer examination of the individual leg forces shows that these differences stem from the behavior of the middle and rear legs and points to suggestions for future designs and further experimentation. Force Plate Sagittal Plane Trajectory of Center of Mass Ground Reaction Force Vectors (minus gravity) Running Direction