Setting Environment Variables

Once you have completed the previous tutorial sections, you are now ready to use the environment variables interface provided by the Robot Customizer ROS package!

The complete list of supported sensors and environment variables can be found here.

In this section of the tutorial, we will go through an example usage of the environment variables interface for a SICK LMS1xx 2D laser scanner.

  1. Enable the SICK LMS1xx 2D laser scanner. In terminal, run:

export CPR_LASER=1
export CPR_LASER_MODEL=lms1xx

  1. Choose a link in your robot model (defined in your robot’s .urdf.xacro file) to mount the SICK LMS1xx 2D laser scanner. Feel free to adjust the XYZ and RPY coordinates of the SICK LMS1xx 2D laser scanner relative to the chosen link. For example, we will mount it on the box link in the generic_robot.urdf.xacro file, offset slightly in the negative x and positive z directions. In terminal, run:

export CPR_LASER_PARENT=box
export CPR_LASER_XYZ="-0.1 0 0.12"
export CPR_LASER_RPY="0 0 0"

  1. Choose a ROS topic that the driver launch file will publish 2D laser scan data to. For example, we will choose to have the 2D laser scan data published to the /scan ROS topic. In terminal, run:

export CPR_LASER_TOPIC=scan

  1. Choose the IP address assigned to the SICK LMS1xx 2D laser scanner. This will let the driver launch file know where to detect it, and allow it to start retrieving 2D laser scan data. From factory, the IP address of the SICK LMS1xx 2D laser scanner is set to 192.168.0.10. In terminal, run:

export CPR_LASER_IP=192.168.0.10

  1. At this point, you can try launching your robot’s .launch file. The description.launch file used in generic robot example will be used for this tutorial. In terminal, run:

roslaunch cpr_robot_customizer description.launch

  1. If your SICK LMS1xx 2D laser scanner is connected to your robot’s computer and with the IP address configured correctly, then launching the .launch file should automatically launch the SICK LMS1xx 2D laser scanner’s driver. You can verify this by checking the output in your terminal, and also by checking the 2D laser scan data currently being published in ROS. In terminal, run:

rostopic echo /scan

The state of your robot (based on your robot’s model) will also be published to ROS; however, you currently will not be able to visually verify this. Please see the next section to learn how to visualize your robot’s model, the sensors attached to it, and the sensors’ data in rviz.

  1. The environment variables set in steps 1. to 4. will only be set in that terminal session, meaning upon closing that terminal session, those environment variables will be unset! In order to keep the desired values of environment variables persistent, you can simply add the export ENVAR=VALUE lines to your robot’s ~/.bashrc file; this way, those environment variables will be set upon booting the robot’s computer, and will remain persistent in any terminal session.