Gonçalo, Thanks for the package, I'll take a look at things. To run a different local planner, you'll want to change the plugin that move_base loads. The relevant parameters are documented here: http://www.ros.org/wiki/move_base#Parameters You'll set base_local_planner to be something like dwa_local_planner/DWAPlannerROS. You'll also need to make sure the dwa_local_planner library is made before running move_base as it'll be loaded at runtime. Hope this helps, Eitan 2010/11/18 Gonçalo Cabrita > Sorry Eitan! > > I should have sent everything compressed the first time! I compressed the > pkg. To run it just put it on your ROS_PACKAGE_PATH, roscore, roscd > roomba_stage and then open stage, launch move_base and open rviz (also > sending a roomba_stage.vcg file): > > rosrun stage stageros roomba_lse_arena.world > roslaunch roomba_stage move_base_lse_arena.launch > > Just send the robot to the top right corner and it will likely stall on the > wall. > > Anyways I just downloaded navigation_experimental! So dwa_local_planner > seems to be a lib, how should I use it to get the robot up and running with > it? Just give me some quick pointers. > > Cheers, > > Gonçalo Cabrita > ISR - University of Coimbra > Portugal > > On Thu, Nov 18, 2010 at 7:02 PM, Eitan Marder-Eppstein < > eitan@willowgarage.com> wrote: > >> Gonçalo, >> >> It looks like you missed a file called "arena_obstalces.pgm" in what you >> sent which is needed by the roomba_ise_arena.world file. Is there any way >> you can just tar up the package you use to bring things up? Ideally this >> would include all the configuration files and launch files you're using to >> bring up stage and the navigation stack and would save a bit of grief in me >> recreating the same package on my end. >> >> Thanks a bunch, >> >> Eitan >> >> 2010/11/18 Gonçalo Cabrita >> >>> Hi Eitan! >>> >>> Thanks for your reply. >>> >>> I'm attaching the files needed to run the sim on Stage. It is the same >>> setup we have on the real arena right now, and the results on the real robot >>> are pretty similar to the simulation. >>> >>> I'll most definitely take a look at the experimental nav stack. I'd like >>> to try the dwa_local_planner on the roomba to see what happens! I'll be >>> posting some feedback and most likely a bunch of questions! >>> >>> Gonçalo Cabrita >>> ISR - University of Coimbra >>> Portugal >>> >>> >>> On Thu, Nov 18, 2010 at 5:54 PM, Eitan Marder-Eppstein < >>> eitan@willowgarage.com> wrote: >>> >>>> Hey guys, >>>> >>>> So, to join in the discussion. From the video, it looks like the >>>> base_local_planner gets stuck in a local minimum with the parameters >>>> configured as they are. Is there any way that you can post the package used >>>> to create that video so that I can play around a little bit? I've wanted to >>>> have a case in simulation where a diff drive robot behaves badly and it >>>> seems like this is a simple one that could help me track down some issues >>>> the navigation stack has with diff drive robots. With that said, its true >>>> that no one local planner is going to fit all robots. >>>> >>>> We've started development of some other local planners in the >>>> navigation_experimental stack that might also be worth checking out. One is >>>> called dwa_local_planner and is a much cleaner version of the >>>> base_local_planner that includes things like scaling the robot's footprint >>>> based on speed, allowing for holonomic robots to explore more of the y >>>> velocity space, and exposing parameters via dynamic reconfigure to make >>>> tuning them a lot easier... we're testing it on the PR2 right now, not sure >>>> how it'll work on a diff-drive robot. There's also the pose_follower which >>>> attempts to follow a plan exactly, stopping in the presence of obstacles. >>>> This also hasn't been tested on diff-drive robots and I'd expect it could >>>> use a few tweaks to really work well, but it might be something to look at. >>>> One thing to keep in mind with all this, however, is that the packages in >>>> navigation_experimental are, well, experimental, so you're likely to run >>>> into some issues from time to time, there are no guarantees about API >>>> stability yet, and documentation isn't great. >>>> >>>> Hope all is well and please do post the simulation package as I'd love >>>> to take a look at things, >>>> >>>> Eitan >>>> >>>> 2010/11/18 Gonçalo Cabrita >>>> >>>> We've been a bit busy porting everything that moves around here to ROS! >>>>> We'll update our repository in the next week with everything we've got! >>>>> >>>>> I'm attaching the param files we use for the roombas. >>>>> >>>>> I'm surprised the creates don't have decent odometry since they were >>>>> design for research. We have considered using cheap webcams with visual >>>>> odometry to replace the roomba's odometry, but I haven't had time to look >>>>> into it. If my memory serves me when we opened a roomba we found a hall >>>>> sensor with 4 magnets tied to the motor shaft. So I'm guessing direction is >>>>> determined by the motor speed. And that why when you push the roomba the >>>>> odometry doesn't count back! >>>>> >>>>> I'm really interested in solving this matter. If the problem really is >>>>> from the nav stack we're in big trouble since everything here is diff drive! >>>>> We have roombas, erratics and scouts! >>>>> >>>>> Gonçalo Cabrita >>>>> ISR - University of Coimbra >>>>> Portugal >>>>> >>>>> >>>>> On Thu, Nov 18, 2010 at 3:45 PM, Steven Martin < >>>>> s34.martin@connect.qut.edu.au> wrote: >>>>> >>>>>> Yeh I think my problem is related to odometry, the iCreates don't >>>>>> have any encoders. I thought they did but after looking closer at the driver >>>>>> I am pretty sure its just openloop. Do you have the parameters for amcl in >>>>>> your repository? I had a look but couldn't see them anywhere. >>>>>> >>>>>> I have the code for the pursuit path follower checked in @ >>>>>> launchpad.net/cmr but its very incomplete. It will compile, you can >>>>>> launch it and it will try and follow a path but it doesn't have any obstacle >>>>>> avoidance and I think I have one of my signs wrong in the code as it didn't >>>>>> appear to do much following from the very limited testing I have done. >>>>>> >>>>>> Have a look, its basically as stripped down as I could make a local >>>>>> path planner while still fitting in the ROS framework. Also due to the >>>>>> pretty well useless iCreate odometry I chose to implement this in the global >>>>>> frame and this may have some adverse affects if you are only running >>>>>> localiser @ 3Hz. >>>>>> >>>>>> I will probably have time to look at this next week but I think this >>>>>> is a problem for anybody using nonholonomic robots with the Nav Stack so I >>>>>> would be surprised if someone else hasn't already got a better solution. >>>>>> >>>>>> Steve >>>>>> >>>>>> ------------------------------ >>>>>> *From:* ros-users-bounces@code.ros.org [ >>>>>> ros-users-bounces@code.ros.org] on behalf of Gonçalo Cabrita [ >>>>>> goncabrita@gmail.com] >>>>>> *Sent:* Friday, 19 November 2010 12:52 AM >>>>>> *To:* User discussions >>>>>> *Subject:* Re: [ros-users] Navigation Stack on tight places >>>>>> >>>>>> Hi Steven! >>>>>> >>>>>> "ts not a failure case but do you also see the one where it turns a >>>>>> little bit away from the path then does loop around to rejoin it.?" >>>>>> >>>>>> You we also get that a lot! The robot never sticks to the path the >>>>>> planner outputs, it wonders around a lot. >>>>>> >>>>>> We are using Roombas 560 with Eee PCs and Hokuyo lasers. We launch >>>>>> the Roomba the laser and the tf broadcaster on one file and map server, amcl >>>>>> and move base on another one. We have the map updaters running at 3Hz and >>>>>> the path planner at 5Hz. Still sometimes the EeePC skips a loop! >>>>>> Furthermore, I dunno how the Create is but our Roombas have nasty odometry! >>>>>> The encoders have only 1 channel with 4 pulses per motor turn! >>>>>> >>>>>> Anyways, I'm not familiar with the nav stack code, but I would like >>>>>> to help if possible! >>>>>> >>>>>> Gonçalo Cabrita >>>>>> ISR - University of Coimbra >>>>>> Portugal >>>>>> >>>>>> On Thu, Nov 18, 2010 at 2:35 PM, Steven Martin < >>>>>> s34.martin@connect.qut.edu.au> wrote: >>>>>> >>>>>>> Yep see that one all the time. I think the implementation of DWA is >>>>>>> flawed for tank steer robots. >>>>>>> >>>>>>> Its not a failure case but do you also see the one where it turns a >>>>>>> little bit away from the path then does loop around to rejoin it.? >>>>>>> >>>>>>> I started implementing just pure pursuit path follower to replace DWA >>>>>>> but haven't quite got it working and been too busy with other stuff. I think >>>>>>> we need to implement some other local planners or just path followers. >>>>>>> >>>>>>> Also what are you using for the localization? I haven't been able to >>>>>>> get AMCL to work reliably on the iCreates. >>>>>>> ------------------------------ >>>>>>> *From:* ros-users-bounces@code.ros.org [ >>>>>>> ros-users-bounces@code.ros.org] on behalf of Gonçalo Cabrita [ >>>>>>> goncabrita@gmail.com] >>>>>>> *Sent:* Thursday, 18 November 2010 11:51 PM >>>>>>> *To:* ros-users@code.ros.org >>>>>>> *Subject:* [ros-users] Navigation Stack on tight places >>>>>>> >>>>>>> Hi everyone! >>>>>>> >>>>>>> We've been using the nav stack on our Roombas for quite a while >>>>>>> now, mostly on the corridors of ISR without any problems. >>>>>>> >>>>>>> However we have a small 4mx3m arena we built specifically for >>>>>>> testing odor search algorithms in which we recently started to run some >>>>>>> experiments. We quickly found out that the nav stack has some problems >>>>>>> moving the robot around in tight places. Quite often we get >>>>>>> the behavior that can be seen in the following video... >>>>>>> >>>>>>> http://www.youtube.com/watch?v=vy9xoNvmktg >>>>>>> >>>>>>> In the video we are running a Roomba inside our arena in Stage with >>>>>>> perfect odometry. The robot stalls against a wall and stays there for >>>>>>> 30mins until we stop it. On occasion the robot eventually gets out after a >>>>>>> while. >>>>>>> >>>>>>> At first I thought this could be happening because of the poor >>>>>>> performance of the EeePCs the Roombas carry around or because of the >>>>>>> Roomba's crappy odometry, but in Stage on a Core2Duo laptop we were able to >>>>>>> see the same behavior. >>>>>>> >>>>>>> Has anyone experienced this behavior before? >>>>>>> >>>>>>> _______________________________________________ >>>>>>> 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 >>>> >>>> >>> >>> _______________________________________________ >>> 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 > >