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Inverse dynamics control with floating base and constraints


Conference Paper


In this paper, we address the issues of compliant control of a robot under contact constraints with a goal of using joint space based pattern generators as movement primitives, as often considered in the studies of legged locomotion and biological motor control. For this purpose, we explore inverse dynamics control of constrained dynamical systems. When the system is overconstrained, it is not straightforward to formulate an inverse dynamics control law since the problem becomes an ill-posed one, where infinitely many combinations of joint torques are possible to achieve the desired joint accelerations. The goal of this paper is to develop a general and computationally efficient inverse dynamics algorithm for a robot with a free floating base and constraints. We suggest an approximate way of computing inverse dynamics algorithm by treating constraint forces computed with a Lagrange multiplier method as simply external forces based on FeatherstoneÕs floating base formulation of inverse dynamics. We present how all the necessary quantities to compute our controller can be efficiently extracted from FeatherstoneÕs spatial notation of robot dynamics. We evaluate the effectiveness of the suggested approach on a simulated biped robot model.

Author(s): Nakanishi, J. and Mistry, M. and Schaal, S.
Book Title: International Conference on Robotics and Automation (ICRA2007)
Pages: 1942-1947
Year: 2007

Department(s): Autonomous Motion
Bibtex Type: Conference Paper (inproceedings)

Address: Rome, Italy, April 10-14
Cross Ref: p2597
Note: clmc
URL: http://www-clmc.usc.edu/publications/N/nakanishi-ICRA2007.pdf


  title = {Inverse dynamics control with floating base and constraints},
  author = {Nakanishi, J. and Mistry, M. and Schaal, S.},
  booktitle = {International Conference on Robotics and Automation (ICRA2007)},
  pages = {1942-1947},
  address = {Rome, Italy, April 10-14},
  year = {2007},
  note = {clmc},
  crossref = {p2597},
  url = {http://www-clmc.usc.edu/publications/N/nakanishi-ICRA2007.pdf}