Running with the center of mass on the hip is far from optimal

Running with the center of mass on the hip is far from optimal

Van Oijen, T.P.

Wisse, M. (mentor)

Mechanical, Maritime and Materials Engineering

BMechE

BMD

2010-04-08

Running robots often have their center of mass (CoM) located on the hip. This decouples the pitching and CoMdynamics and therefore allows for simple control schemes. However, by creating an offset between the CoM and the hip, and herewith introducing coupling between the pitching and CoMdynamics, the performance of the running robot might possibly increase. In this simulation study, we calculated the optimal CoMlocation for a running robot with hip actuation. We measured the performance of the system as the largest step-down and push that can be corrected in one or two steps. We found that the largest step-down can be corrected in one step when the CoM is located above the hip. The largest push on the other hand can be corrected when the CoM is located under the hip. For two-steps recovery strategies, placing the CoM exactly on the hip is the worst option out of all possible CoM-locations. In this case, the corresponding disturbance rejection is approximately a factor 10 worse than for the optimal CoM-location. Therefore, we conclude that placing the CoM of the torso on the hip is far from optimal.

running

http://resolver.tudelft.nl/uuid:18d78798-2b9c-4356-923f-e088f1b21779

2011-04-08

Student theses

master thesis

(c) 2010 Van Oijen, T.P.