Optimal control of a half circular compliant legged monopod

Özkan Aydın, Yasemin
Legged robots have complex architecture because of their nonlinear dynamics and unpredictable ground contact characteristics. They can be also dynamically stable and exhibit dynamically dexterous behaviors like running, jumping, flipping which require complex plant models that may sometimes be difficult to build. In this thesis, we focused on half circular compliant legged monopod that can be considered as a reduced-order dynamical model for the hexapod robot, called RHex. The main objective of this thesis is the development of an algorithm based on opti- mal control theory that allows a half circular compliant legged monopod to run with a desired forward velocity or height starting from rest. The algorithm optimizes the foot attack angle and parameters of the PD controller while minimizing the error be- tween desired and actual velocity. The effectiveness of the developed control strategy is verified by a variety of computer simulations. After obtaining a wide range of constant velocity running, we designed another energy-efficient controller which can effectively perform one of the dynamic behaviors, jumping motion. The jumping motion increases the maneuverability of the robot on the variety of rough terrain in a qualitatively satisfying manner. We analyze the performance of the our jumping con- trol with a different jumping task, called triple jumping motivated by the exceptional performance of triple jumper athletes.


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Citation Formats
Y. Özkan Aydın, “Optimal control of a half circular compliant legged monopod,” Ph.D. - Doctoral Program, Middle East Technical University, 2013.