On Tue, Dec 7, 2010 at 7:29 PM, Eitan Marder-Eppstein < eitan@willowgarage.com> wrote: > 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. > Took longer than I expected to get a chance to work on it, but I did finally get a chance to change to using a boost::function and moving the visualizer to TrajectoryPlannerROS. Changes are again available in my github repository mentioned above. I've also created a ticket to track getting this committed to the nav stack (https://code.ros.org/trac/ros-pkg/ticket/4620) so that any further discussion about the particulars can be discussed there. - Eric > > 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 >> >> > > _______________________________________________ > ros-users mailing list > ros-users@code.ros.org > https://code.ros.org/mailman/listinfo/ros-users > >