Step-over behavior for Limit Cycle Walkers

Step-over behavior for Limit Cycle Walkers

Van Nieuwenhuizen, N.

Van der Helm, F.C.T. (mentor)
Wisse, M. (mentor)

Mechanical, Maritime and Materials Engineering

BMechE

BMD

2009-10-23

In this paper, stepping over a zero height obstacle with minimal actuation is studied for a limit cycle walker modeled as a double inverted pendulum. The obstacle position is estimated by stereo vision. Actuation is realized by a constant torque per step on the hip and a push-off collinear to the trailing leg. Stepping over the obstacle must be accomplished with the obstacle position exactly on a predefined position in between the legs with the final state right after push-off being equal to the initial state. Thus, at least two steps must be taken to perform this task, such that the first step is used to make sure the relative position of the obstacle is correct. In the best case scenario, the obstacle is exactly in between the legs during a nominal walk. In that case, actuation does not have to be adjusted with respect to the nominal actuation. In the worst case scenario the obstacle is exactly at a stepping position. In that case, a translation of the step positions is needed. For stepping over in two steps this is not possible; this is only possible for a small range around the best case scenario. For stepping over in three steps this is possible when actuation is applied according to the optimization results presented.

limit cycle walker

http://resolver.tudelft.nl/uuid:976e0a59-ba87-4dee-a5de-5c3b4d8b7e7a

Student theses

master thesis

(c) 2009 Van Nieuwenhuizen, N.