[ros-users] Actuating a wheeled robot URDF model in gazebo

[David Feil-Seifer]

OK, I tried using the erratic model, with no luck. I got the following message:

Node: /gazebo_1278058054452352000
Time: 12.532000000
Severity: Warn
Location: ros/stacks/pr2_mechanism/pr2_mechanism_model/src/robot.cpp:RobotState::RobotState:170
Published Topics: /rosout, /clock, /base_scan,
/base_pose_ground_truth, /joint_states, /mechanism_statistics

None of the joints in the robot desription matches up to a motor. The
robot is uncontrollable.

I tried adding a transmission, even though this was stated to be
pr2-only on the wiki (see attached file), and that made the above
error go away, but there was still no way to control the robot. While
it was publishing a /base_pose_ground_truth topic, there was no
subscription to anything other than /clock and /time. Is there some
other way to defined motors in urdf for gazebo?

A related question. The rear caster wheel is un-actuated. Is there any
way for that joint to be published by default to a certain angle?
Unless gazebo publishes an angle (which currently it will not without
a transmission), the links will not show up in rviz. Obviously, this
is not nearly as important, but a cosmetic issue.

Thanks in advance,
Dave

On Tue, Jun 29, 2010 at 12:01 PM, John Hsu <johnhsu at willowgarage.com> wrote:
> There is an erratic model in gazebo with 2dnav stack hooked up.
> You'll need to get the unreleased wg-ros-pkg repository for this to work,
>
> svn co https://code.ros.org/svn/wg-ros-pkg/trunk wg-ros-pkg-unreleased
>
> The package is:
>
> /u/johnhsu/projects/cturtle_wg_all/wg-ros-pkg-unreleased/stacks/wg_robots_gazebo/erratic_gazebo
>
> This is an unreleased stack, but should be in working state:
>
> rosmake erratic_gazebo
> roslaunch erratic_gazebo erratic_2dnav_demo.launch
>
> Let me know if you run into any issues.
> John
>
>
> On Tue, Jun 29, 2010 at 11:53 AM, David Feil-Seifer
> <david.feilseifer at gmail.com> wrote:
>>
>> I am trying to make a urdf model for the pioneer 3dx robot that can be
>> used in gazebo. The robot is a 2-wheeled diff drive robot with a singe
>> rear caster.I have the robot visualizing correctly in rviz. However, I
>> want this robot to be drivable. I am a little unclear from the wiki
>> tutorials regarding gazebo and urdf on how to accomplish this? Is the
>> GazeboRosDiffdrive node something that I could use for the pioneer as
>> well as the erratic? What information do I need to have about the
>> pioneer in order to make a urdf model work in gazebo?
>> _______________________________________________
>> ros-users mailing list
>> ros-users at code.ros.org
>> https://code.ros.org/mailman/listinfo/ros-users
>
>
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