%0 Conference Paper %B 2011 IEEE/RSJ International Conference on Intelligent RObots and Systems %D 2011 %T Optimality Principles in Variable Stiffness Control: the VSA Hammer %A M. Garabini %A A. Passaglia %A F. A. W. Belo %A P Salaris %A A. Bicchi %K Robotics %B 2011 IEEE/RSJ International Conference on Intelligent RObots and Systems %C S. Francisco, USA %P 3770 - 3775 %8 September 25 - 3 %G eng