Unit 2 : URDF course : Getting an error No transform from [roll_M1_link] to [base_link]

[muhammadjunaid]

Hi !

Due to some reason , I am getting an error in RVIZ. Also When I added TF in rviz , I cannot see the status option with it aswell (screenshot attached) :

can anyone help me over here

Best regards,
Muhammad

[munn33b]

Is your robot_state_publisher node running? This node is responsible for publishing transforms

[muhammadjunaid]

Hi munn!
Thanks for your response , Yes it is running , here is the launch file :

<launch>

  <!-- USE: roslaunch my_mira_description urdf_visualize.launch model:='$(find myrobot_package)/urdf/myrobot.urdf' -->
  <arg name="model" default=""/>


  <param name="robot_description" command="cat $(arg model)" />

  <!-- send fake joint values -->
  <!--<node name="joint_state_publisher_gui" pkg="joint_state_publisher_gui" type="joint_state_publisher_gui"/> -->

    <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher">
      <param name="use_gui" value="TRUE"/>
  </node>

  <!-- Combine joint values -->
  <node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher"/>

  <!-- Show in Rviz   -->
  <!--<node name="rviz" pkg="rviz" type="rviz" args="-d $(find my_mira_description)/rviz_config/urdf.rviz"/>-->
  <node name="rviz" pkg="rviz" type="rviz" args=""/>

</launch>

and here is the screenshot of the terminal :

and here is the screen shot of gazebo :

I also have added the URDF below :

<?xml version="1.0" ?>

<robot name="robot">

    <!-- Link - chassis -->
    <link name="link_chassis">
        <inertial>
            <mass value="10" />
            <origin xyz="0 0 0.3" rpy="0 0 0" />
            <inertia ixx="1.5417" ixy="0" ixz="0" iyy="3.467" iyz="0" izz="4.742" />
        </inertial>

        <collision>
            <geometry>
                <box size="2 1.3 0.4" />
            </geometry>
        </collision>

        <visual>
            <geometry>
                <box size="2 1.3 0.4" />
            </geometry>
            <material name="Red">
                <color rgba="1 0 0 1" />
            </material>
        </visual>
    </link>

    <!-- Joint - chassis / left wheel -->
    <joint name="joint_chassis_left_wheel" type="continuous">
        <origin rpy="0 0 0" xyz="-0.5 0.65 0" />
        <child link="link_left_wheel" />
        <parent link="link_chassis" />
        <axis rpy="0 0 0" xyz="0 1 0" />
        <limit effort="10000" velocity="1000" />
        <joint_properties damping="1.0" friction="1.0" />
    </joint>

    <!-- Link - left wheel -->
    <link name="link_left_wheel">
        <inertial>
            <mass value="1" />
            <origin xyz="0 0 0" rpy="0 0 0" />
            <inertia ixx="0.002526666666667" ixy="0" ixz="0" iyy="0.002526666666667" iyz="0" izz="0.005"/>
        </inertial>

        <collision>
            <origin rpy="1.5707 0 0" xyz="0 0.18 0" />
            <geometry>
                <cylinder length="0.12" radius="0.4"/>
            </geometry>
        </collision>
        <visual>
            <origin rpy="1.5707 0 0" xyz="0 0.18 0" />
            <geometry>
                <cylinder length="0.12" radius="0.4"/>
            </geometry>
        </visual>

        <collision>
            <origin rpy="1.5707 0 0" xyz="0 0.06 0" />
            <geometry>
                <cylinder length="0.12" radius="0.08"/>
            </geometry>
        </collision>
        <visual>
            <origin rpy="1.5707 0 0" xyz="0 0.06 0" />
            <geometry>
                <cylinder length="0.12" radius="0.08"/>
            </geometry>
        </visual>
    </link>

</robot>

[munn33b]

As a work around, you may try runnning

 <arg name="use_tf_static" default="false"/> 
 <node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher" >
          <param name="use_tf_static" value="$(arg use_tf_static)"/>
 </node>

[muhammadjunaid]

I have tried this :

But still the same issue. It says on RVIZ : no TF data

<launch>

  <!-- USE: roslaunch my_mira_description urdf_visualize.launch model:='$(find myrobot_package)/urdf/myrobot.urdf' -->
  <arg name="model" default=""/>


  <param name="robot_description" command="cat $(arg model)" />

  <!-- send fake joint values -->
  <!--<node name="joint_state_publisher_gui" pkg="joint_state_publisher_gui" type="joint_state_publisher_gui"/> -->

  <node name="joint_state_publisher" pkg="joint_state_publisher" type="joint_state_publisher">
    <param name="use_gui" value="TRUE"/>
  </node>

  <!-- Combine joint values -->
  <arg name="use_tf_static" default="false"/> 
  <node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher" >
    <param name="use_tf_static" value="$(arg use_tf_static)"/>
  </node>
  <!-- Show in Rviz   -->
  <!--<node name="rviz" pkg="rviz" type="rviz" args="-d $(find my_mira_description)/rviz_config/urdf.rviz"/>-->
  <node name="rviz" pkg="rviz" type="rviz" args=""/>

</launch>

[duckfrost2]

Hi,

Can you pots here the TF Tree? or at least echo the tf topic? Because if the robot state publisher is running it should at least generate the tf tree

[Davis2015]

Hi @muhammadjunaid
Can you try to un-comment :

  <!--<node name="joint_state_publisher_gui" pkg="joint_state_publisher_gui" type="joint_state_publisher_gui"/> -->

The robot_state_publisher node is running and that what is responsible for publishing transforms.