0
Research Papers

Redundancy Resolution Using Tractrix—Simulations and Experiments

[+] Author and Article Information
V. C. Ravi

 Center for AI and Robotics, Bangalore 560093, Indiavc_ravi@cair.drdo.in

Subrata Rakshit

 Center for AI and Robotics, Bangalore 560093, Indiasrakshit@cair.drdo.in

Ashitava Ghosal1

Department of Mechanical Engineering, Indian Institute of Science, Bangalore 560012, Indiaasitava@mecheng.iisc.ernet.in

Proteins are linear heterobiopolymers comprising of amino acid residues (1). A simplistic and classical physics based model of a protein backbone consists of 50–500 amino acid residues connected by two degree-of-freedom joints and, hence, can be thought of as a large hyper-redundant serial manipulator.

We can discretize a “large” step into ”smaller” steps for numerical simulation.

1

Corresponding author.

J. Mechanisms Robotics 2(3), 031013 (Jul 23, 2010) (7 pages) doi:10.1115/1.4001777 History: Received August 26, 2009; Revised March 03, 2010; Published July 23, 2010; Online July 23, 2010

Hyper-redundant robots are characterized by the presence of a large number of actuated joints, a lot more than the number required to perform a given task. These robots have been proposed and used for many applications involving avoiding obstacles or, in general, to provide enhanced dexterity in performing tasks. Making effective use of the extra degrees-of-freedom or resolution of redundancy has been an extensive topic of research and several methods have been proposed in literature. In this paper, we compare three known methods and show that an algorithm based on a classical curve, called the tractrix, leads to a more “natural” motion of the hyper-redundant robot with the displacements diminishing from the end-effector to the fixed base. In addition, since the actuators nearer the base “see” a greater inertia due to the links farther away, smaller motion of the actuators nearer the base results in better motion of the end-effector as compared with other two approaches. We present simulation and experimental results performed on a prototype eight-link planar hyper-redundant manipulator.

FIGURES IN THIS ARTICLE
<>
Copyright © 2010 by American Society of Mechanical Engineers
Your Session has timed out. Please sign back in to continue.

References

Figures

Grahic Jump Location
Figure 1

Motion of a link when one end is pulled along the line ST parallel X-axis

Grahic Jump Location
Figure 5

Plot of joint variables for circular trajectory

Grahic Jump Location
Figure 6

Experimental eight-link hyper-redundant manipulator

Grahic Jump Location
Figure 7

Snapshots of hyper-redundant manipulator executing straight line trajectories

Grahic Jump Location
Figure 8

Snapshots of hyper-redundant manipulator executing circular trajectories

Grahic Jump Location
Figure 2

Motion of a link when one end is pulled along the line ye=mxe

Grahic Jump Location
Figure 3

Desired straight line and circular end-effector trajectories

Grahic Jump Location
Figure 4

Plot of joint variables for straight line trajectories

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