Comment by moshahin for I am building my own 4WD model and I am trying to implement 4 velocity controllers (one for each motor). The issue arises when I execute my launch file (which contains the controller_spawner node), the transforms between the base_link and the 4 wheels are non-existent. I have tried the joint_state_publisher node with the GUI (instead of the controller_spawner) and it works. However when I implement the controller_spawner node, the transforms disappear. I have made sure to download all necessary packages for ros_control. I have used the ros_control plugin in my URDF and even made sure the namespaces are all correct in the YAML, URDF and launch file. Every time I execute the launch file, I get the error: "Controller Spawner couldn't find the expected controller_manager ROS interface."Then I get the error within Rviz that there are no transforms between the base_link and the wheels. When I run rospack list | grep control I get: control_msgs /opt/ros/melodic/share/control_msgs control_toolbox /opt/ros/melodic/share/control_toolbox controller_interface /opt/ros/melodic/share/controller_interface controller_manager /opt/ros/melodic/share/controller_manager controller_manager_msgs /opt/ros/melodic/share/controller_manager_msgs diff_drive_controller /opt/ros/melodic/share/diff_drive_controller effort_controllers /opt/ros/melodic/share/effort_controllers force_torque_sensor_controller /opt/ros/melodic/share/force_torque_sensor_controller forward_command_controller /opt/ros/melodic/share/forward_command_controller gazebo_ros_control /opt/ros/melodic/share/gazebo_ros_control gripper_action_controller /opt/ros/melodic/share/gripper_action_controller imu_sensor_controller /opt/ros/melodic/share/imu_sensor_controller joint_state_controller /opt/ros/melodic/share/joint_state_controller joint_trajectory_controller /opt/ros/melodic/share/joint_trajectory_controller position_controllers /opt/ros/melodic/share/position_controllers velocity_controllers /opt/ros/melodic/share/velocity_controllers My launch file is: <launch> <!--Load the URDF file --> <param name="robot_description" command="cat $(find monsterborg_description)/urdf/monsterborg.urdf"/> <!-- Launch the robot_state_publisher to broadcast transforms to '/tf' --> <node name="robot_state_publisher" pkg="robot_state_publisher" type="robot_state_publisher" output="screen"> <!-- remap from="/joint_states" to="/monsterborg/joint_states"/--> </node> <!-- Load the configuration of the joint controllers --> <rosparam file='$(find monsterborg_description)/config/monsterborg_controllers.yaml' command='load'/> <!-- Load the joint controllers --> <node name='controller_spawner' pkg='controller_manager' type='spawner' respawn='false' output='screen' ns='/monsterborg' args='rf_wheel_velocity_controller rb_wheel_velocity_controller lf_wheel_velocity_controller lb_wheel_velocity_controller joint_state_controller'/> <!-- Loads the 'world' static frame --> <node pkg='tf' type='static_transform_publisher' name='world_frame' args='0 0 0 0 0 0 /world /base_link 100'/> <!-- Open Rviz with specific configuration --> <node name="rviz" pkg="rviz" type="rviz" args="-d $(find monsterborg_description)/rviz_config/monsterborg.rviz"/> </launch> My YAML: monsterborg: joint_state_controller: type: joint_state_controller/JointStateController publish_rate: 50 rf_wheel_velocity_controller: type: effort_controllers/JointVelocityController joint: base_to_rf_wheel pid: {p: 1.0, i: 1.0, d: 1.0} lf_wheel_velocity_controller: type: effort_controllers/JointVelocityController joint: base_to_lf_wheel pid: {p: 1.0, i: 1.0, d: 1.0} rb_wheel_velocity_controller: type: effort_controllers/JointVelocityController joint: base_to_rb_wheel pid: {p: 1.0, i: 1.0, d: 1.0} lb_wheel_velocity_controller: type: effort_controllers/JointVelocityController joint: base_to_lb_wheel pid: {p: 1.0, i: 1.0, d: 1.0} Here is a small snippet of the URDF file for the base_link, one wheel and motor: <robot name="monsterborg"><link name="base_link"> <visual> <origin xyz="0 0 0 ...(more)

@Weasfas In the launch file I posted, I created a static transform `/world` that the `base_link` is connected to. I made sure to set the `fixed_frame` as `/world` but the same thing happened. Has it maybe something to do with the fact that when I created a launch file (other than the one posted) to spawn the model in gazebo I have included: Do I need to connect the Gazebo world to Rviz so that the robot can move around?