Eric, On Tue, Dec 7, 2010 at 3:27 PM, Eric Perko wrote: > Eitan, > > On Tue, Dec 7, 2010 at 1:43 PM, Eitan Marder-Eppstein < > eitan@willowgarage.com> wrote: > >> Eric, >> >> First off, this is awesome! Its a great tool that I'd love to take back to >> the navigation stack. To make it more useful for other local planners, it >> might be nice to have the MapGridVisualizer take in something like a >> boost::function or function ptr for computing the cost of a given cell. It >> could call that function with x and y map coordinates and get back >> goal_cost, path_cost, occ_cost, and total_cost. This would also mean that we >> might get away with not making the MapGrid for the planners public. Instead, >> each planner that wants to publish this information just implements this >> function that the MapGridVisualizer can call. Another option would be to add >> such a function to the BaseLocalPlanner interface instead, but requiring a >> planner to implement it makes a lot of assumptions about the way it works >> and I don't think it belongs there. >> > > I like the idea of just providing a way for a local planner to basically > register an arbitrary cost function with the visualizer. Heck, it would even > be a quick and easy way to prototype new cost functions and see what sort of > effects they have on the potential field. I'll play around with this tonight > or tomorrow and see how it goes. Thanks for the idea. > Sounds good. Let me know when you've got something and I'll take a look at it. Hope all is well, Eitan > > >> Let me know what you think, and thanks for passing this along, definitely >> cool, >> > > Glad you also think it will be useful :) > > - Eric > > >> >> Eitan >> >> On Mon, Dec 6, 2010 at 11:30 PM, Eric Perko wrote: >> >>> Hey all, >>> >>> So, last time I worked with tuning the cost scoring parameters of >>> base_local_planner it was tricky due to no way to easily tell how each term >>> in the cost function was influencing the scored trajectories. To address >>> this problem, I've created a class that outputs a PointCloud2 on a topic >>> called cost_cloud under the base_local_planner namespace that contains the >>> cost information for each component of the cost function as well as the >>> total cost for each point the MapGrid maintained by the TrajectoryPlanner >>> class. You can find the code here: >>> https://github.com/ericperko/ros_navigation . You can find some sample >>> images from rviz at >>> http://www.dropbox.com/gallery/1970299/1/BaseLocalPlannerVizSamples?h=885d40 , >>> files named by which cost value they are visualizing (hover over the >>> thumbnails to see the filenames or click for the gallery view and it will be >>> listed below the thumbnails at the top), to give you all an idea of what >>> this code outputs (red is lowest cost). >>> >>> There are a few steps to actually being able to use this functionality: >>> >>> >>> 1. Checkout the updated Nav Stack from >>> https://github.com/ericperko/ros_navigation or otherwise apply >>> commit >>> https://github.com/ericperko/ros_navigation/commit/00ec9847100942767a80524b401fc8c26e652d02 to >>> your existing base_local_planner package & recompile it. >>> 2. Update your base_local_planner_params.yaml file with two more >>> parameters: >>> 1. "publish_cost_grid_pc" to true. Default is false so that people >>> who aren't interested in seeing the point cloud aren't wasting cycles making >>> & publishing it. >>> 2. "global_frame_id" to whatever your local costmap's global frame >>> is. By default, this is "odom" to match the setup in the nav stack setup ( >>> http://www.ros.org/wiki/navigation/Tutorials/RobotSetup ). This is >>> the frame id set for the output point cloud so will determine how it draws >>> in the map. >>> 3. Now you should be able to verify that base_local_planner is >>> outputting a PointCloud using something like "rostopic hz >>> /move_base/TrajectoryPlannerROS/cost_cloud" >>> 4. In order to visualize the PointCloud in a meaningful way, you will >>> have to apply the patch in >>> https://code.ros.org/trac/ros-pkg/ticket/4610 to RViz so that you can >>> treat arbitrary channels as intensity data. The visualization will be much >>> more readable if you also make sure to check the "Use full RGB spectrum" box >>> so that gradients are more apparent. >>> 5. Have fun selecting different components of the cost function and >>> seeing what sort of affect they have on the potential field that >>> base_local_planner is sampling trajectories from! Note that we don't output >>> any points that have any cost component greater than max cost and would >>> therefore be illegal for the planner to try to execute. >>> >>> Feedback would be very welcome and I hope this comes in handy. I know >>> it's already helped me out by letting me see that my obstacle cost field >>> doesn't extend as far as I might like. >>> >>> Eitan, any feedback on changes that are required to make this more >>> general for use in, for example, dwa_local_planner would be great. Also, the >>> C++ API of TrajectoryPlanner would likely have to change slightly if we >>> wanted to move the visualizer and it's use of ROS topics and parameters up >>> to TrajectoryPlannerROS. Specifically, the MapGrid would either need to >>> become public or we'd need to add a getter for it; currently it's private to >>> the TrajectorPlanner, so that's where the MapGridVisualizer is instantiated. >>> Either that or pass in a number of variables in the constructor/setter >>> methods (especially the scaling values). Let me know what you think would be >>> the best idea for improving it, as I was currently going for a minimally >>> invasive patch to start with and would like to get a more finalized patch >>> together before opening a ticket to add this to the nav_stack. >>> >>> - Eric >>> >>> _______________________________________________ >>> 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 > >