0
RESEARCH PAPERS

Robot Finger Stiffness Control in the Presence of Mechanical Nonlinearities

[+] Author and Article Information
R. Vossoughi, M. Donath

University of Minnesota, Productivity Center, Department of Mechanical Engineering, Minneapolis, Minn. 55455

J. Dyn. Sys., Meas., Control 110(3), 236-245 (Sep 01, 1988) (10 pages) doi:10.1115/1.3152677 History: Received October 29, 1987; Online July 21, 2009

Abstract

Stiffness control provides a mechanism for controlling finger position or force, and facilitates stable behavior during the transition between unconstrained motion and sudden contact with the environment. The method proposed here provides uniformity of response upon finger contact for any contact stiffness, as long as no separation occurs. The stiffness control system of a finger joint in a robot hand was partitioned into linear and nonlinear subsystems. The controller design used pole placement techniques based on the linear subsystem while the mechanical nonlinearities (i.e., load and velocity dependent nonlinear friction and nonlinear damping) in the drive were modeled separately. The parameters of the nonlinear model were experimentally identified off-line. These identified parameters were then used in a real-time estimator for compensation of the nonlinear effects while the system was under stiffness control. The technique was implemented successfully at 40 HZ on the actual finger under investigation. The results are a significant improvement on traditional techniques for nonlinear systems which result in large offsets or unstable behavior.

Copyright © 1988 by ASME
Your Session has timed out. Please sign back in to continue.

References

Figures

Tables

Errata

Discussions

Some tools below are only available to our subscribers or users with an online account.

Related Content

Customize your page view by dragging and repositioning the boxes below.

Related Journal Articles
Related eBook Content
Topic Collections

Sorry! You do not have access to this content. For assistance or to subscribe, please contact us:

  • TELEPHONE: 1-800-843-2763 (Toll-free in the USA)
  • EMAIL: asmedigitalcollection@asme.org
Sign In