Hi guys, Willing to reopen this thread... And I have 2 remarks to start with: Should we consider that REP-i0003 is a direct answer to last year's API review on cartesian trajectories?I really believe that the trajectory definition and the way this trajectory is achieved (e.g. via impedance control) are 2 different subjects which should be treated in isolation: let us first make the cartesian trajectory definition good and then later we can build on it for impedance control. But really cartesian trajectory is path and impedance is control: complementary but different subjects. Thanks, Antoine. From: konradb3@gmail.com Date: Fri, 7 Jun 2013 09:12:37 +0200 To: ros-users@code.ros.org CC: ros-sig-robot-control@googlegroups.com Subject: Re: [ros-users] cartesian trajectories After considering some of possible use-cases i came up with yet another proposal (more detailed) : [1] http://ros.org/wiki/trajectory_msgs/Reviews/Cartesian%20Trajectories_API_Review_2013_06_05 Pozdrawiam Konrad Banachowicz 2013/6/6 Konrad Banachowicz Yes it is definitely out of scope of simple cartesian trajectory but it contains sub-message CartesianTrajectory which is simple and quiet self contained. I think that such complex goal message gives us good basis for discussion on it's building blocks like : CartesianTrajectory, CartesianImpedance .... Pozdrawiam Konrad Banachowicz 2013/6/6 Georg Bartels On 06/05/2013 09:40 PM, Jonathan Bohren wrote: On Wed, Jun 5, 2013 at 1:18 PM, Konrad Banachowicz wrote: [CartesianTrajectoryGoal] Header header # A stamp of 0 means "execute now" string[] effector_names CartesianTrajectory[] trajectory PoseStamped tool # The frame which is being controlled CartesianTrajectoryPoint[] points duration time_from_start Pose pose Twist twist CartesianImpedance[] impedance TBD stiffness % cartesian stiffness TBD damping % damping ratio CartesianTolerance[] path_tolerance # Tolerance for aborting the path float64 position float64 orientation # Permitted angular error float64 velocity float64 angular_velocity CartesianTolerance[] goal_tolerance # Tolerance for when reaching the goal is considered successful JointTrajectory posture # For determining the redundancy JointImpedance nullspace_impedance # TBD I like where this version is going! Konrad's proposition looks indeed promising. However, I'd like to point out that this is more than a Cartesian Trajectory. This looks more like a goal message to a very sophisticated controller, e.g. whole-body motion framework or iTaSC. Shouldn't the Cartesian Trajectory msg be somewhat smaller in scope and then be reused? Maybe more like in the spirit of std_msgs which are mainly used as building blocks for bigger and semantically annotated messages? Meanwhile, between comments in different mailing lists, and comments on the wiki in the old robot_mechanism_controllers, it'd be great if we could aggregate this discussion. Really it seems like this is an extension to the trajectory_msgs package, so maybe we can do an online review where people can propose and comment on different options and subjects. I've started one [1] with the initial proposal from the old wg review, and added Konrad's proposal above (feel free to remove/edit that, Konrad). I think we can use the robot control SIG to coordinate, and ping ros-users for high-level notices. Then when we've at least gotten the scope down, we can initiate an REP request. How does that sound? [1] http://ros.org/wiki/trajectory_msgs/Reviews/Cartesian%20Trajectories_API_Review_2013_06_05 Good idea. From now on moving to the REP? -j -- Jonathan Bohren Laboratory for Computational Sensing and Robotics http://dscl.lcsr.jhu.edu/People/JonathanBohren _______________________________________________ ros-users mailing list ros-users@code.ros.org https://code.ros.org/mailman/listinfo/ros-users _______________________________________________ ros-users mailing list ros-users@code.ros.org https://code.ros.org/mailman/listinfo/ros-users _______________________________________________ ros-users mailing list ros-users@code.ros.org https://code.ros.org/mailman/listinfo/ros-users