Affiliation:
1. Robotics and Motion Laboratory, Department of Mechanical Engineering, University of Michigan, Ann Arbor, MI 48109 e-mail:
2. Equine Department, Vetsuisse Faculty, University of Zurich, Zurich CH-8057, Switzerland e-mail:
Abstract
This paper presents a simplistic passive dynamic model that is able to create realistic quadrupedal walking, tölting, and trotting motions. The model is inspired by the bipedal spring loaded inverted pendulum (SLIP) model and consists of a distributed mass on four massless legs. Each of the legs is either in ground contact, retracted for swing, or is ready for touch down with a predefined angle of attack. Different gaits, that is, periodic motions differing in interlimb coordination patterns, are generated by choosing different initial model states. Contact patterns and ground reaction forces (GRFs) evolve solely from these initial conditions. By identifying appropriate system parameters in an optimization framework, the model is able to closely match experimentally recorded vertical GRFs of walking and trotting of Warmblood horses, and of tölting of Icelandic horses. In a detailed study, we investigated the sensitivity of the obtained solutions with respect to all states and parameters and quantified the improvement in fitting GRF by including an additional head and neck segment. Our work suggests that quadrupedal gaits are merely different dynamic modes of the same structural system and that we can interpret different gaits as different nonlinear elastic oscillations that propel an animal forward.
Subject
Applied Mathematics,Mechanical Engineering,Control and Systems Engineering,Applied Mathematics,Mechanical Engineering,Control and Systems Engineering
Reference30 articles.
1. Mechanical Work and Efficiency in Level Walking and Running;J. Physiol.,1977
2. Passive Dynamic Walking;Int. J. Rob. Res.,1990
3. A Movement Criterion for Running;J. Biomech.,2002
4. Mechanical Work in Terrestrial Locomotion: Two Basic Mechanisms for Minimizing Energy Expenditure;Am. J. Physiol.,1977
5. Ballistic Walking: An Improved Model;Math. Biosci.,1980
Cited by
27 articles.
订阅此论文施引文献
订阅此论文施引文献,注册后可以免费订阅5篇论文的施引文献,订阅后可以查看论文全部施引文献