Using min-max of torque to resolve redundancy for a mobile manipulator [electronic resource].

Published:: Washington, D.C. : United States. Dept. of Energy, 1991.
Oak Ridge, Tenn. : Distributed by the Office of Scientific and Technical Information, U.S. Dept. of Energy.
Physical Description:: Pages: (32 pages) : digital, PDF file
Additional Creators:: Oak Ridge National Laboratory, United States. Department of Energy, and United States. Department of Energy. Office of Scientific and Technical Information

Access Online

www.osti.gov

Availability

Finding items...

Restrictions on Access:

Free-to-read Unrestricted online access

Summary:

We have considered the problem of determining the time trajectories of the joint variables of a mobile manipulator with many redundant degrees of freedom that will minimize the maximum value of the torque during a large scale motion by the manipulator. Conventional search techniques slowly solve min-max problems. Based on well known results from the Tchebycheff approximation of functions, we conjecture that at the min-max the magnitude of the normalized torques will be equal at all of the joints. It is an easier problem to find the values of the joint variables that equalize the torques than to perform a large set of slow searches. Furthermore, paths that equate the torques are likely to be continuous in joint space. We have explored paths that equalize the magnitude of the normalized torques for a three link planar manipulator on a platform and for the seven degree of freedom CESARm on a three degree of freedom platform. For the planar arm, we find many analytical solutions that minimize the torque in various regions of the workspace. For the CESARm, the most attractive solution covers a wide range of the workspace and has only one discontinuity in a joint variable. We have found paths that can bridge the discontinuity at a small penalty of increased torque. Paths that equate the torques are attractive candidates for large scale motion by a mobile manipulator. 4 refs., 12 figs.

Report Numbers:

E 1.99:conf-920540-5
conf-920540-5

Subject(s):

Other Subject(s):

Note:

Published through SciTech Connect.
01/01/1991.
"conf-920540-5"
"DE92000070"
1992 Institute of Electrical and Electronics Engineers (IEEE) international conference on robotics and automation, Nice (France), 10-15 May 1992.
Reister, D.B.

Funding Information:

AC05-84OR21400

View MARC record | catkey: 14115090