[Bug 1010] New: weighted positional solver ( ChainIkSolverPos_NR_JL_WE )

jelle <[email protected]>
Newsgroups gmane.science.robotics.orocos.devel
Message-ID <[email protected]/>
http://bugs.orocos.org/show_bug.cgi?id=1010

           Summary: weighted positional solver ( ChainIkSolverPos_NR_JL_WE
                    )
           Product: KDL
           Version: unspecified
          Platform: All
        OS/Version: All
            Status: NEW
          Severity: enhancement
          Priority: P3
         Component: Kinematic Solvers
        AssignedTo: [email protected]
        ReportedBy: [email protected]
   Estimated Hours: 0.0


Created attachment 842
  --> http://bugs.orocos.org/attachment.cgi?id=842
pibgeus ChainIkSolverPos_NR_JL_WE implementation

An old thread on ROS [1] discussed the need for a position IK solver than takes
weighting into account.
Another thread on orocos-users [2] confirmed this need.
A preliminary version has been contributed by pibgeus, though there are issues
with this implementation, as pointed out by Erwin Aertbelien: 

============ ==================
pibgeus talks about weights on xyz RPY but in the code the weights are on the
displacement twist (i.e. the result of KDL's diff(..) )

You should also be sure to use a weighted inv. vel. kin.

However, this would not completely solved the problems with the 5 dof robots,
since the weights are still
a diagonal matrix.  With these type of weights you cannot specify that the
rotation along a given axes is irrelevant.
You'll need a full symmetric matrix ( or its square root) to specify such a
thing.  And even with a full symmetric matrix
it will be annoying to use (because you have to construct the weighing matrix
and that requires some insight).
Better would be in this case to be able to specify the weighing matrix relative
to the end effector.
==============================

[1] http://ros-users.122217.n3.nabble.com/IK-with-KDL-td1867716.html
[2] http://www.orocos.org/forum/orocos/orocos-users/help-5-dof-arm

-- 
Configure bugmail: http://bugs.orocos.org/userprefs.cgi?tab=email
------- You are receiving this mail because: -------
You are the assignee for the bug.
-- 
Orocos-Dev mailing list
[email protected]
http://lists.mech.kuleuven.be/mailman/listinfo/orocos-dev
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.