Take a look at the new version of this page: [ beta version ]. Tell us what you think.

ABSTRACT

We demonstrate a real-time simulation system capable of automatically balancing a standing character, while at the same time tracking a reference motion and responding to external perturbations. The system is general to non-human morphologies and results in natural balancing motions employing the entire body (for example, wind-milling). Our novel balance routine seeks to control the linear and angular momenta of the character. We demonstrate how momentum is related to the center of mass and center of pressure of the character and derive control rules to change these centers for balance. The desired momentum changes are reconciled with the objective of tracking the reference motion through an optimization routine which produces target joint accelerations. A hybrid inverse/forward dynamics algorithm determines joint torques based on these joint accelerations and the ground reaction forces. Finally, the joint torques are applied to the free-standing character simulation. We demonstrate results for following both motion capture and keyframe data as well as both human and non-human morphologies in presence of a variety of conditions and disturbances.

REFERENCES

• 1: Abdallah, M., and Goswami, A. 2005. A biomechanically motivated two-phase strategy for biped upright balance control. In IEEE Int. Conf. Robotics and Automation.
• 2: Yeuhi Abe , Marco da Silva , Jovan Popović, Multiobjective control with frictional contacts, Proceedings of the 2007 ACM SIGGRAPH/Eurographics symposium on Computer animation, August 02-04, 2007, San Diego, California
• 3: Brian Allen , Derek Chu , Ari Shapiro , Petros Faloutsos, On the beat!: timing and tension for dynamic characters, Proceedings of the 2007 ACM SIGGRAPH/Eurographics symposium on Computer animation, August 02-04, 2007, San Diego, California
• 4: Okan Arikan , David A. Forsyth , James F. O'Brien, Pushing people around, Proceedings of the 2005 ACM SIGGRAPH/Eurographics symposium on Computer animation, July 29-31, 2005, Los Angeles, California [doi>10.1145/1073368.1073376]
• 5: Marco da Silva , Yeuhi Abe , Jovan Popović, Interactive simulation of stylized human locomotion, ACM Transactions on Graphics (TOG), v.27 n.3, August 2008
• 6: DaSilva, M., Abe, Y., and Popović, J. 2008. Simulation of Human Motion Data using Short-Horizon Model-Predictive Control. Computer Graphics Forum, 27(2).
• 7: Roy Featherstone , Kluwer Academic Publishers, Robot Dynamics Algorithm, Kluwer Academic Publishers, Norwell, MA, 1987
• 8: Featherstone, R. 2000. Robot dynamics: Equations and algorithms. In IEEE Int. Conf. Robotics and Automation.
• 9: Goswami, A., and Kallem, V. 2004. Rate of change of angular momentum and balance maintenance of biped robots. IEEE Int. Conf. Robotics and Automation.
• 10: Hofmann, A., Massaquoi, S., Popovic, M., and Herr, H. 2004. A sliding controller for bipedal balancing using integrated movement of contact and non-contact limbs. In Intelligent Robots and Systems.
• 11: Kajita, S., Kanehiro, F., Kaneko, K., Fujiwara, K., Harada, K., Yokoi, K., and Hirukawa, H. 2003. Resolved momentum control: humanoid motion planning based on the linear and angular momentum. Intelligent Robots and Systems.
• 12: Taku Komura , Howard Leung , James Kuffner, Animating reactive motions for biped locomotion, Proceedings of the ACM symposium on Virtual reality software and technology, November 10-12, 2004, Hong Kong [doi>10.1145/1077534.1077542]
• 13: Taku Komura , Edmond S. L. Ho , Rynson W. H. Lau, Animating reactive motion using momentum-based inverse kinematics: Motion Capture and Retrieval, Computer Animation and Virtual Worlds, v.16 n.3-4, p.213-223, July 2005 [doi>10.1002/cav.v16:3/4]
• 14: Kudoh, S., Komura, T., and Ikeuchi, K. 2002. The dynamic postural adjustment with the quadratic programming method. In Intelligent Robots and Systems.
• 15: Kudoh, S., Komura, T., and Ikeuchi, K. 2006. Stepping motion for a humanlike character to maintain balance against large perturbations. In IEEE Int. Conf. Robotics and Automation.
• 16: Macchietto, A., 2008. Momentum-based control for simulated characters. Master's Thesis, University of California, Riverside.
• 17: Mandel, M., 2004. Versatile and interactive virtual humans. Master's Thesis, Carnegie Mellon University.
• 18: Orin, D., and Goswami, A. 2008. Centroidal momentum matrix of a humanoid robot: Structure and properties. In Intelligent Robots and Systems.
• 19: Popovic, M., Hofmann, A., and Herr, H. 2004. Angular momentum regulation during human walking: biomechanics and control. IEEE Int. Conf. Robotics and Automation.
• 20: Popovic, M., Hofmann, A., and Herr, H. 2004. Zero spin angular momentum control: definition and applicability. IEEE/RAS International Conference on Humanoid Robots.
• 21: Ari Shapiro , Fred Pighin , Petros Faloutsos, Hybrid Control for Interactive Character Animation, Proceedings of the 11th Pacific Conference on Computer Graphics and Applications, p.455, October 08-10, 2003
• 22: Kwang Won Sok , Manmyung Kim , Jehee Lee, Simulating biped behaviors from human motion data, ACM Transactions on Graphics (TOG), v.26 n.3, July 2007
• 23: Stephens, B. 2007. Humanoid Push Recovery. In IEEE-RAS International Conference on Humanoid Robots.
• 24: Wooten, W., and Hodgins, J. 2000. Simulating leaping, tumbling, landing and balancing humans. IEEE Int. Conf. Robotics and Automation.
• 25: KangKang Yin , Michael B. Cline , Dinesh K. Pai, Motion Perturbation Based on Simple Neuromotor Control Models, Proceedings of the 11th Pacific Conference on Computer Graphics and Applications, p.445, October 08-10, 2003
• 26: Yin, K., Pai, D., and van de Panne, M. 2005. Data-driven interactive balancing behaviors. Pacific Graphics.
• 27: KangKang Yin , Kevin Loken , Michiel van de Panne, SIMBICON: simple biped locomotion control, ACM Transactions on Graphics (TOG), v.26 n.3, July 2007
• 28: KangKang Yin , Stelian Coros , Philippe Beaudoin , Michiel van de Panne, Continuation methods for adapting simulated skills, ACM Transactions on Graphics (TOG), v.27 n.3, August 2008
• 29: Victor Brian Zordan , Jessica K. Hodgins, Motion capture-driven simulations that hit and react, Proceedings of the 2002 ACM SIGGRAPH/Eurographics symposium on Computer animation, July 21-22, 2002, San Antonio, Texas [doi>10.1145/545261.545276]
• 30: Victor Brian Zordan , Anna Majkowska , Bill Chiu , Matthew Fast, Dynamic response for motion capture animation, ACM Transactions on Graphics (TOG), v.24 n.3, July 2005

INDEX TERMS

Primary Classification:
  I. Computing Methodologies
  I.3 COMPUTER GRAPHICS
      I.3.7 Three-Dimensional Graphics and Realism
          Subjects: Animation

Keywords:
character animation, physics-based animation