I wrote the node, but a while ago, so I can't be sure, but Ithink that I sent a "pulse" message every 1s to keep that watchdog from kicking in. However, by default it is turned off. Try setting the "pulse" parameter to 1. -Dave On Fri, Apr 23, 2010 at 8:24 AM, Brian Gerkey wrote: > It's been a long time since I used a Pioneer, and I haven't looked at > the node that you're using, so this is shooting in the dark: > > If I recall correctly, the microcontroller implements a watchdog that > will stop the motors if it hasn't heard a velocity command over the > serial line after a certain amount of time.  If you send commands too > slowly, the watchdog would kick in between commands, causing the robot > to move a bit, halt, move a bit, halt, etc. I believe that the > watchdog is configurable, or at least can be turned on or off, which > might account for the different in behavior between your robots. > > Something to try is to make the node resend the last received velocity > to the robot at a relatively high rate (10Hz should be enough).  Of > course, the node should then implement its own watchdog, which would > send zero velocities if it hasn't received a command via ROS after > some time. > >        brian. > > On Fri, Apr 23, 2010 at 6:56 AM, Tucker Hermans wrote: >> Dan, >> Without being able to investigate your setup further, the only thing I can >> think is that the commands being sent over the serial connection are either >> experiencing high latency or are being sent to infrequently, so that the >> velocity commands sent to the microcontroller are far enough apart that you >> get the stuttering effect. >> I tried reproducing this by setting a very high time (30s as opposed to 2s) >> to resend velocity commands but this had no effect.  Are you seeing >> statements from the p2os node of the form "new speed [0.25, 0.0] >> (timestamp)" and "setting vel: [0.25,0.0]".  If not what kind of debug >> output are you seeing on the node? >> -Tucker >> >> On Thu, Apr 22, 2010 at 12:31 PM, Dan Lazewatsky >> wrote: >>> >>> I just tried out a few things from your pioneer_control package and I get >>> the same behavior I was seeing before. >>> >>> -Dan >>> >>> On 4/21/10 7:13 PM, Dan Lazewatsky wrote: >>> >>> Hi Tucker, >>> I think that should be enough to get me going. >>> >>> Thanks! >>> -Dan >>> >>> On 4/21/10 6:57 PM, Tucker Hermans wrote: >>> >>> Hi Dan, >>> I send the MotorState command of 4 and have no problems. >>> I have a teleop keyboard port which I use for communicating with the p3dx >>> that you can find >>> here: github.com/trhermans/AffLearning/tree/master/pioneer_control/ >>> Note: the launch file is setup for a p3dx with a PTZ connected to an >>> onboard computer and uses the probe camera driver to get the video stream. >>> I have only been testing the changes to the p2os package on a p3dx with an >>> onboard computer, I don't think this should have any issues, but it could. >>> Let me know if the keyboard operation gives the same problems you have now >>> and I'll try and help debug it. >>> -Tucker >>> >>> On Wed, Apr 21, 2010 at 7:49 PM, Dan Lazewatsky >>> wrote: >>>> >>>> Hi all - >>>> I know this has been discussed here a bit, but not in much detail. >>>> We have a Pioneer3dx that we'd like to get up and running again. I >>>> downloaded and compiled the p2os package which seems to be able to >>>> successfully connect and communicate with the robot using a serial to >>>> USB adapter. However, I'm having trouble getting the motors to do >>>> anything sensible. The robot's motor self-test looks like it works fine, >>>> but sending cmd_vel, all I can get is extremely slow, jerky movement >>>> forward or backwards (no turning). I enabled the motors with: >>>> >>>> rostopic pub cmd_motor_state -1 p2os/MotorState 1 (I also tried 4 >>>> instead of 1 which was mentioned in a previous discussion) >>>> >>>> This feels like a communication problem between the motor commands p2os >>>> is sending and the robot, but I don't know what's going on. Any ideas? >>>> >>>> Thanks, >>>> -Dan >>>> _______________________________________________ >>>> 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 >