2011/1/18 Sachin Chitta > Hi Konrad, > > The GetKinematicSolverInfo was intended as a read-only information service > that would provide information about the joint limits used in the solver. > The service itself is a convenience service and not really essential since > most of the information comes from the robot description. Note that none of > the services impose any conditions on where the limits are sourced from. > Currently, they are sourced from the robot description internally in the > node but I could add an api where you can override those limits using ROS > parameters. > ok so there should be corresponding for "plugins" > RobotState is intended for complete representation of a generic robot state > and not just an arm. I am not sure what you mean by "contains alot of > unnecessary data". Could you please clarify which fields are unnecessary. > I was thinking about multi_dof_joint_state field and vellocity and effort fields of joint_state. Those field seem to be ignored by kinematics solvers. > I expect the core kinematics services (GetPositionIK, GetPositionFK) > themselves to be stable. The only possible change is to add a "group name" > so you would not have to specify every joint to be used by the solver. The > other possible change would be to add a new service that lets you call IK on > a vector of poses to save the trouble of calling a service multiple times. I > would prefer not to do a wholesale change of API but would like to get some > of the convenience elements (like group names) in. > > I do have an "plugin" implementation of the kinematics in place right now > but I have not pushed it out. It lets you configure and call solvers using > the plugin architecture used by other components in ROS (like the navigation > stack). I will push it out for review in a few days after putting up more > documentation. > Documentation would be very useful. > You are welcome to send more such feedback. In fact, if anyone would like > to step up and volunteer to help maintain the kinematics stacks and do some > of these API changes (like Jack O'Quinn is maintaining camera drivers), that > would be more than welcome. > I have created kinematics_utils package containing useful functions from pr2_kinematics_utils and node capable of loading kinematics plugins and providing kinematics sevices. > Sachin > > > On Sun, Jan 16, 2011 at 11:09 AM, Konrad Banachowicz wrote: > >> 2011/1/16 Herman Bruyninckx >> >>> On Sun, 16 Jan 2011, Konrad Banachowicz wrote: >>> >>> I started to move our code for our robot kinematics to ROS. >>>> I would like to know what is the stabilization status of kinematics >>>> stack, >>>> because latst review happend nearly year ago. >>>> I have some remarks and suggestions about kinematics stack : >>>> - kinematics serwices use motion_planning_msgs/RobotState which contains >>>> alot of >>>> unnecessary data. >>>> - SolverInfo contains limits field which duplicate data avalible through >>>> robot_description. >>>> >>> >>> You might want to configure a solver with tighter limits than what the >>> robot's mechanics impose... >> >> ok but those data are read-only by getSolverInfo service. >> Currently every implementation simply send data readed from >> robot_description. >> >>> >>> >>> - pr2_kinematics contains many useful functions in >>>> pr2_arm_kinematics_utils.cpp >>>> this could be moved to common package, maybe kinematics_utils. >>>> >>>> - common node for ik and ik_with_constraints should exist, using >>>> kinematics >>>> plugins. >>>> This would simplify implementation of kinematics for new robot. >>>> >>> >>> Herman >>> _______________________________________________ >>> 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 >> >> > > > -- > Sachin Chitta > Research Scientist > Willow Garage > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > >