link/rt_nofriction - remove friction from a link object[view code]

Calling Sequence

link2 = rt_nofriction(link [, "all"])

Parameters

• link : link object. It describes the link kinematics and dynamics.
• link2 : link object. A clone of link with modified joint friction properties.

Description

Return a new link object with modified joint friction properties. If the optional string "all" is not specified, then the function sets the Coulomb friction values to zero. Else, both viscous and Coulomb friction values are set to zero.

This is important for forward dynamics computation (see rt_fdyn) where the presence of friction can prevent the numerical integration from converging.

Examples

   // The following example shows how rt_nofriction() can be used to remove
   // viscous and Coulomb friction from waist joint of a Puma 560 robot
   exec <PATH>/models/rt_puma560.sce;       // load Puma 560 parameters
   wjoint = p560.links(1);                  // waist joint
   rt_showlink(wjoint);

   // A new link which has Coulomb friction values set to zero
   wj_nocf = rt_nofriction(wjoint);
   rt_showlink(wj_nocf);

   // A new link which has both viscous and Coulomb friction values set to
   // zero
   wj_noall = rt_nofriction(wjoint, "all");
   rt_showlink(wj_noall);
   
  

See Also

rt_link,  link/rt_friction,  rt_robot,  robot/rt_nofriction,  robot/rt_friction,  rt_fdyn,  

Authors

original Matlab version by

Peter I. Corke CSIRO Manufacturing Science and Technology

Scilab implementation by

Matteo Morelli Interdepartmental Research Center "E. Piaggio", University of Pisa

Bibliography

Corke, P.I. "A Robotics Toolbox for MATLAB", IEEE Robotics and Automation Magazine, Volume 3(1), March 1996, pp. 24-32