Abstract

This paper describes a method for optimizing the parameters of a physics-based controller for full-body, 3D walking. A modified version of the SIMBICON controller [Yin et al. 2007] is optimized for characters of varying body shape, walking speed and step length.  The objective function includes terms for power minimization, angular momentum minimization, and minimal head motion, among others. Together these terms produce a number of important features of natural walking, including active toe-off, near-passive knee swing, and leg extension during swing.  We explain the specific form of our objective criteria, and show the importance of each term to walking style. We demonstrate optimized controllers for walking with different speeds, variation in body shape, and in ground slope.

People

Jack M. Wang
David J. Fleet
Aaron Hertzmann

Paper

Wang, J. M., Fleet, D. J., Hertzmann, A. Optimizing Walking Controllers. ACM Transactions on Graphics 28, 5 (Proceedings of SIGGRAPH Asia 2009), Article 168, December 2009, 8 pages.

Slides

SIGGRAPH Asia talk slides.

Video

High resolution (640x480)
Low resolution (320x240)

Acknowledgements

The authors are indebted to Peter O’Donovan for his tireless video production efforts, and Martin de Lasa and Igor Mordatch for inspiring technical discussions. We thank Prof. Nikolaus Troje for providing the ground truth mocap walking data, Prof. Michiel van de Panne and KangKang Yin for providing detailed information regarding SIMBICON, and Nikolaus Hansen for his publicly available CMA implementation.  This research is supported in part by CFI, CIFAR, Microsoft Research, NSERC, and Ontario MRI.