loading urdf to rviz problem

asked 2020-06-04 07:41:19 -0600

pluma615 gravatar image

updated 2022-03-20 09:37:44 -0600

lucasw gravatar image

Hello, guys. I am a beginner in ROS and I ran into some problem while I was trying to build a SolidWorks 3D model, export it as URDF and visualize the model for trajectory planning in RViz.

First, I was able to export my SolidWorks model as URDF. Then I created a catkin workspace, copy-pasted my urdf folder containing my robot model, configured my catkin workspace and sourced it according to the tutorial.

Then, I used roslaunch to run my display.launch file in RViz. However, I'm getting an error here which says

Global status: Error
Fixed Frame: Fixed Frame [map] does not exist

To solve this issue, I googled and found this code:

rosrun tf static_transform_publisher 0.0 0.0 0.0 0.0 0.0 0.0 map my_frame 100

So I ran it on a separate terminal and the problem went away. (I still don't know what the problem was and how this code solved it so if you could explain it, I would appreciate it.)

After that, I could click "Add" and "Motion Planning" to load the 3D model into the space. However, all the functions (MotionPlanning, PlanningScene, etc.) have oragne warning sign which says "Status:Warn"

Can anybody please explain me what the problem is? Thank you.

edit retag flag offensive close merge delete

Comments

Hi @pluma615,

RViz is just a visualization tool and it needs a Fixed frame to render properly all things in ROS space. You can change this value in the Global options > Fixed Frame menu in the left panel of the GUI. Hence, you do not need to publish a static transform to visualize properly, you can just change the fixed frame to a known (existent) frame your robot_description is generating. I assume you tf_tree is properly set, you can check it by using the command: rosrun rqt_tf_tree rqt_tf_tree. Since the map frame does not exist in your tf tree rviz is unable to apply the proper transformation for all the rest of the robot_description frames, thus Rviz is unable to render it.

As for the other warning, it can be your tfs are not properly generated or you have a missed connection somewhere. At this point is really difficult ...(more)

Weasfas gravatar image Weasfas  ( 2020-06-05 06:21:17 -0600 )edit

The same solution as the one stated in my other comment applies with the answer updated. Rviz is just a visualization tool that uses the TF information to display ROS data. If there is not a proper tf tree set up that connects the frame "map" with your "base_link" any data displayed in Rviz with a Fixed frame: "map" will not going to be properly drawn. Just take a look at the frames convention.

Weasfas gravatar image Weasfas  ( 2022-03-26 07:49:14 -0600 )edit