Ewellix Common Packages

ROS2 description, MoveIt configuration, and interface packages for the Ewellix TLT lifts.

Ewellix Driver Package

See the Ewellix driver repository for more information on commanding a real lift through ROS.

Ewellix Visualization

The ewellix_viz package provides a launch file to load the URDF using specific lift parameters and display it in RViz.

By default, the tlt_x25 lift is used. This lift has a 500 mm stroke, but has a taller base than the tlt_x15 that provides less torque.

ros2 launch ewellix_viz rviz_model.launch.py

Lift Parameters

To switch to a different lift type, pass in a different configuration file using the lift_parameters launch parameter. For example, the Ewellix UR 620 designed to mount UR manipulators can be selected as follows:

ros2 launch ewellix_viz rviz_model.launch.py lift_parameters:=/path/to/ewellix_description/config/ur_620.yaml

Change the /path/to/ path prefix with the path to the ur_620.yaml in the ewellix_description package

Base Plate

It is also possible to the move the base plate and mounting plate from the model.

To remove the base plate, use the add_plate launch argument:

ros2 launch ewellix_viz rviz_model.launch.py lift_parameters:=/path/to/ewellix_description/config/ur_620.yaml add_plate:=false

Mounting Plate

To remove the mounting plate, use the add_mount launch argument:

ros2 launch ewellix_viz rviz_model.launch.py lift_parameters:=/path/to/ewellix_description/config/ur_620.yaml add_mount:=false

Ewellix Simulation

The simulation requires Gazebo installed from the ROS vendor packages. Use rosdep to install the dependencies on the ewellix_sim package.

Use the same parameters from the Ewellix Visualization section to select a lift type, then launch the simulation from the ewellix_sim package launch file.

ros2 launch ewellix_sim simulation.launch.py lift_parameters:=/path/to/ewellix_description/config/ur_620.yaml add_mount:=true add_plate:=true

Simulation without MoveIt!

By default, the controller loaded to the simulated ROS 2 control plugin is the JointGroupPositionController using the jpc.yaml. This controller allows the desired position of the lift to be set directly by the user through the /lift_position_controller/commands topic.

After starting the simulation, use the following command to set the height of the lift:

ros2 topic pub /lift_position_controller/commands std_msgs/msg/Float64MultiArray 'layout:
  dim: []
  data_offset: 0
data: [0.2]
'

The command above directs the lift to move its joints to position 0.2. Since the two joints are mirrored, the total vertical offset from the zero-th position is 0.4.

Simulation with MoveIt!

To simulate the lift with the JointTrajectoryController compatible with MoveIt!, set the controller_file to jtc.yaml and enable moveit. Then, use the MotionPlanning RViz plugin to set the target joint position and then Plan & Execute to move the lift in Gazebo.

ros2 launch ewellix_examples simulation.launch.py lift_parameters:=/path/to/ewellix_description/config/ur_620.yaml add_mount:=true add_plate:=true controller_file:=jtc.yaml moveit:=true rviz:=true