Glad to hear that!

Glad it was helpful!

Glad it helped!

Thank you! Cheers!

I don't have experience with the fusion2urdf plugin but if you seek general information about URDFs I would recommend e.g. this series by TheConstruct (ukposts.info/have/v-deo/eZyWaWuDmpqLxnk.html). As the video is a bit older some syntax is outdated but the concepts still apply. If you want to try out up-to-date code (ROS1 Noetic) with the arm simulated in Gazebo I would recommend this repository of ours where you can find an example and lots of documentation (github.com/lFatality/ros_moveit_gazebo_ws).

You can define a virtual link without any inertia as the first link of the robot (root link). To do so just write an "empty" link: Then use a fixed joint to attach it to your link_1.

Once you have the urdf, you can also place the arm in Gazebo. I think the generated MoveIt! package also contains a launch file to place the arm in Gazebo. If you want to find out how to connect MoveIt! to the simulated arm you can have a look at this repository of mine: github.com/lFatality/ros_moveit_gazebo_ws

do you mean when you load it into the setup assistant? does it show any error message? if you open the urdf file in a text editor, do you see the content you'd expect?

​@@roboticsinanutshell when i execute ''' roslaunch urdf1_config demo.launch''' i obtain the interface of RVIZ without the model

​@@islemhammami3559 when you use roslaunch you also have to provide the package name (roslaunch your_package_name your_launch_file.launch). be sure that you have sourced your workspace (source devel/setup.bash in your workspace root). you should be able to run the launch file while being in the root of your workspace. i understand your problem but you need to answer the questions i asked previously, otherwise i cant help you. one thing you could try is changing the "fixed frame" in rviz. it could also be that you have to add the model of the robot in rviz (in rviz click on add and search for "robot model" (i think, not sure right now. maybe try some different options as well)). usually it should be displayed though without you having to do anything. maybe try going through the steps in the moveit setup assistant again. or check if you can get it to run with another urdf file and then try to find out what the differences between the urdf files are.

@@roboticsinanutshell yes when i load it into the setup assistant and it show this error message "[move_group-4] process has died [pid 4502, exit code -6, cmd /opt/ros/melodic/lib/moveit_ros_move_group/move_group --debug __name:=move_group __log:=/home/is/.ros/log/2505ba62-a53a-11eb-8c69-441ca83b8471/move_group-4.log]. log file: /home/is/.ros/log/2505ba62-a53a-11eb-8c69-441ca83b8471/move_group-4*.log"

@@islemhammami3559 I understood your comment like this: You start the MoveIt Setup Assistant with "roslaunch moveit_setup_assistant setup_assistant.launch", then you click "Create New MoveIt Configuration Package", search for your .urdf file, and when you then click "Load Files", you get the error you posted, correct? Does the setup assistant crash? Is there a popup window? It could be an error with your graphics drivers since the assistant attempts to render the model when you click "Load files". In Linux systems it's often the case that you are using a community-developed graphics driver by default. Changing to the proprietary drivers for your graphics card could solve the problem. Just search how to do it. Other than that this link could help you: answers.ros.org/question/200628/moveit-setup-assistant-crashes-when-loading-a-urdf/ Finally I'd try if the problem also occurs if you follow the official MoveIt tutorial to make sure it's not a problem with your urdf: docs.ros.org/en/melodic/api/moveit_tutorials/html/doc/getting_started/getting_started.html

It seems like you made a typo. The command is "roslaunch", not "roslauch".

@@roboticsinanutshell yes Sir i have corrected my typo mistake. but shows this result "roslaunch moveit_ RLException: [moveit_] is not a launch file name The traceback for the exception was written to the log file

@@YashPatel-xj9qs I assume you want to start the moveit setup assistant. To do so you have to type the command "roslaunch moveit_setup_assistant setup_assistant.launch". When you use roslaunch, the syntax is "roslaunch package_name launch_file_name". If you only type "roslaunch moveit_", then ROS doesn't know what to do since the package name is incomplete and no launch file has been specified. That's why it's giving you an error.

@@roboticsinanutshell Thank you sir for your your reply. But sir i am not able to load file i have error message "ROS was unable to find the package name '' within the ROS workspace. This may cause issues later." in terminal i got this message "[ERROR] [1613409632.218618900]: Error retrieving file [package://urdf_3dof/meshes/base_link.STL]: Package [urdf_3dof] does not exist".

@@YashPatel-xj9qs It can't find the package urdf_3dof. Is your package called urdf_3dof? Did you source your workspace (source devel/setup.bash)? Is the package located in the src folder of your workspace?

Hi there, to see the wheels moving in Rviz, ROS needs to know about the current state of the wheels. This state should be given as TFs (transforms). Transforms are the way in ROS to define a position in space (relative to some other position). To create a TF of the wheel, you first need to know where that wheel currently is (in degrees relative to some zero point). In reality this would be given by a sensor. In the simulation this is provided by Gazebo. To avoid the struggle of having to set up a publisher to publish the current state of each joint, there is a node in ROS called the "joint_state_publisher". This node will publish the state of all your joints to a common topic. How does it know which joints belong to your robot? You load the URDF of your robot as a ROS parameter on the parameter server. How does it know about the joint states? It gets a list of topics where it can get data from. Now you have all the states of the wheels. But if you just say that the wheel is at 30°, that doesn't exactly specify how the wheel is located in space. Instead you need information like this: Relative to the base_link of the robot, the wheel is x, y, z meters away and rotated about the x, y, z axis this many degrees (this is what a TF does). You could calculate this yourself and publish the TFs but there is another package that allows you to do this: the robot_state_publisher. It takes the URDF of your robot and the joint states published by the joint_state_publisher and calculates and publishes the TFs for you. Once the TFs are available, Rviz will display the rotation of the wheels for you. In a launch file this might look like this: To let the robot move around in Rviz when you move it around in the simulation you need mapping and localisation algorithms. You can either do the mapping first, create a map, and then localise yourself in that map. Or you create the map while you move around and try to localize yourself in that map at the same time. This is referred to as SLAM (simultaneous localisation and mapping).

@@roboticsinanutshell Thanks a lot .you explained a big concept in a nutshell.

hello there, i was also trying around with moveit2 a little bit but also wasn't sure how to use it exactly. I didn't spend too much time so maybe I missed it. So at the moment I can't tell you how to use moveit2.

@@roboticsinanutshell tq for your reply

I'm using ros2 as well. How did you install moveit? Colcon build is not working when I try installation of moveit2

I'm not sure I understand the question. In the tutorial a catkin workspace is used (the root folder of the workspace is called ros_ws). In the src folder of the workspace are our URDF files. Using the MoveIt setup assistant we create another ROS package in the workspace that can then be used to control the arm.