Departmental Papers (ESE)



We report on our empirical studies of a new controller for a two-link brachiating robot. Motivated by the pendulum-like motion of an ape's brachiation, we encode this task as the output of a "target dynamical system." Numerical simulations indicate that the resulting controller solves a number of brachiation problems that we term the "ladder," "swing-up," and "rope" problems. Preliminary analysis provides some explanation for this success. The proposed controller is implemented on a physical system in our laboratory. The robot achieves behaviors including "swing locomotion" and "swing up" and is capable of continuous locomotion over several rungs of a ladder. We discuss a number of formal questions whose answers will be required to gain a full understanding of the strengths and weaknesses of this approach.

Document Type

Journal Article

Subject Area

GRASP, Kodlab

Date of this Version



Copyright 2000 IEEE. Reprinted from IEEE Transactions on Robotics and Automation, Volume 16, Issue 2, April 2000, pages 109-123.

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NOTE: At the time of public, Daniel Koditschek was affiliated with the University of Michigan. Currently, he is a faculty member of the School of Engineering at the University of Pennsylvania.


brachiation, dynamically dexterous robotics, limit cycles, locomotion, swing map, symmetry, target dynamics, task encoding, underactuated system



Date Posted: 13 March 2008

This document has been peer reviewed.