HI Patrick, The fifth or sixth entry from a search for "generic kinematics" will throw up this: http://www.ros.org/wiki/arm_kinematics_constraint_aware which is a generic constraint aware kinematics package based on the arm_kinematics package (which itself uses the KDL solvers). Sorry, I don't really know how to get things to go higher in the search results - I think there's an option in the wiki to add keywords but I can't seem to find it right now. That page and the page for the arm_kinematics package should help out in creating your own kinematics node. Hope this helps. Best Regards, Sachin On Mon, Jun 13, 2011 at 11:36 AM, Patrick Beeson wrote: > I'm attempting to try and utilize novel, custom-made 7-DOF modular arm > hardware with ROS, and I'd like any help people are willing to provide > in starting from scratch with getting a new arm working in ROS. I > have lots of familiarity with ROS, writing ROS drivers for perception > and navigation hardware, but, I'm not a manipulation or kinematics > expert, and I'm having difficulties understanding exactly what I do > and do not need to implement on my end to use the move_arm high level > package. > > Having previously used the navigation stack, and other such stacks, I > assumed that I would need some sort of driver that would subscribe to > some topic that would send joint positions or velocities based on > higher level kinematics planning given URDF models of the joints. > Instead, what I found was this tutorial: > > http://www.ros.org/wiki/arm_navigation/Tutorials/Running%20arm%20navigation%20on%20non-PR2%20arm > , > which seems to imply the need for writing my own kinematics plugin in > addition to my own joint trajectory execution node. I can certainly > do this given some time; however, previous emails implied a > generic_kinematics package in unstable that would be useful, but after > searching through the Subversion repository, a generic_kinematics > package does not exist anywhere. > > So, I'm going to start my creating a joint_trajectory_execution node > that has a a joint_trajectory_action interface and does soft-realtime > control of my joints behind the scenes. What I need help determining > is if/where any generic kinematics packages exist or if I need to > write my own for my arm. If I need to write my own, more details on > how to get this working with the other relevant modules would be > useful. If a generic package exists, where is it? How do I feed it > the model of my arm? Also (tutorial step 5) there are lots of other > bits and pieces lying around that need to get tied together that > aren't well documented. All in all, what I need is a better tutorial > that gives a much more simplified explanation as to what pieces are > needed, how they fit together (from move_arm down to hardware > interface), what parameters are definitely needed and which can be > ignored, etc. > > Any help on this would be appreciated. I'm sure I could figure all of > this out given enough time, but these days, time is not a great luxury > that I have, and part of the reason I use ROS is that it has been easy > to create, use, swap nodes, messages, topics with relative ease. the > ARM documentation however is quite lacking and the large number of > motion planning, kinematics, controller, and action modules are not > well documented as to what is deprecated, how things fit together, > etc. > > Thanks in advance, > > Patrick > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > -- Sachin Chitta Research Scientist Willow Garage