Hi Rosen,
I'm trying to use the Transform6DVelocity IkParameterization to add Cartesian velocities to an existing trajectory that contains Transform6D ikparam_values group. The Transform6DVelocity group is, surprisingly, 7-DOF. I'm not sure how to interpret these values because I was expecting a 6-DOF twist. There also are not any helper functions on the IkParameterization class to handle the conversion. What are the values? How do I convert them to/from a twist? Thanks, -Michael ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Openrave-users mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/openrave-users |
Just a guess: are they position+quaternion derivatives? - ChrisOn Mon, Jun 30, 2014 at 5:22 PM, Michael Koval <[hidden email]> wrote: Hi Rosen, ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Openrave-users mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/openrave-users |
In reply to this post by Michael Koval
I have also been hung up way too long on the proper format of what to pass into ikParameterization. This could be documented A LOT better...
Ben Axelrod Sr. Robotics Software Engineer iRobot Corporation 8 Crosby Drive, M/S 8-1 Bedford, MA 01730 (781) 430-3315 [hidden email] ________________________________________ From: Michael Koval [[hidden email]] Sent: Monday, June 30, 2014 5:22 PM To: [hidden email] Subject: [OpenRAVE-users] Interpretation of values in the Transform6DVelocity IkParameterization Hi Rosen, I'm trying to use the Transform6DVelocity IkParameterization to add Cartesian velocities to an existing trajectory that contains Transform6D ikparam_values group. The Transform6DVelocity group is, surprisingly, 7-DOF. I'm not sure how to interpret these values because I was expecting a 6-DOF twist. There also are not any helper functions on the IkParameterization class to handle the conversion. What are the values? How do I convert them to/from a twist? Thanks, -Michael ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Openrave-users mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/openrave-users ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Openrave-users mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/openrave-users |
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hi guys, sorry for the late replies. you are right documentation is lacking, i've also had to look at how the code works internally several times to remind me ;0)in any case Transform6DVelocity is derivative of the quaterion (first 4 values), derivative of the translation (next 3 values). Vector vlinearvel, vangularvel; GetEndEffector()->GetVelocity(vlinearvel, vangularvel); Transform tee = GetTransform(); vlinearvel += vangularvel.cross(tee.trans - GetEndEffector()->GetTransform().trans); Transform tvel; tvel.trans = vlinearvel; tvel.rot = quatMultiply(t.rot,Vector(0,vangularvel.x,vangularvel.y,vangularvel.z)) * 0.5; ikp.SetTransform6DVelocity(tvel); q'(t) = 0.5* q(t) * Quaternion(0, angularvelocity.x, angularvelocity.y, angularvelocity.z) 2014-07-01 9:00 GMT+09:00 Axelrod, Ben <[hidden email]>: I have also been hung up way too long on the proper format of what to pass into ikParameterization. This could be documented A LOT better... ------------------------------------------------------------------------------ Open source business process management suite built on Java and Eclipse Turn processes into business applications with Bonita BPM Community Edition Quickly connect people, data, and systems into organized workflows Winner of BOSSIE, CODIE, OW2 and Gartner awards http://p.sf.net/sfu/Bonitasoft _______________________________________________ Openrave-users mailing list [hidden email] https://lists.sourceforge.net/lists/listinfo/openrave-users |
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