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Detailed Usage

In the following, it is explained how to use the Helmoro ROS architecture. Under helmoro_description/launch/ you will find several launch files:

  • helmoro.launch: Default launch file for Helmoro
  • gmapping_helmoro.launch: Used for gmapping
  • nav_helmoro.launch: Used for the Navigation Stack
  • explore_helmoro.launch: Used for explore_lite
  • showcase_helmoro.launch: Used for the showcase

In the following, only the usage on the main launch file, helmoro.launch, on which all other launch files depend on, is explained. However using the other launch files works analogously. Head to the linked sections to discover more about the purpose and usage of the other launch files.

Run

The main launch file to run all the required nodes of the Helmoro ROS architecture is helmoro.launch in the package helmoro_description.

In order to run Helmoro form a remote PC, you can use ssh as described in the following command.

ssh <username>@<IP-address>

Thereby, type in the username and instead of "IP" type in the IP-address of your Helmoro. Using this command, you can remotely log into the terminal of the Helmoro SBC and thus launch helmoro.launch from your remote device.

Once connected to helmoro via ssh, run the launch file with the following commands:

roslaunch helmoro_description helmoro.launch

Running ROS across Multiple Machines

In some cases, you want to run ROS across multiple machines for example to visualize the published data of Helmoro externally on RViZ. To do so, you can open up two windows in the terminal of one of your machines and connect one of your terminals via ssh to the other machine. Select one machine to run your master on. In our case, this would be the Helmoro. This is where you would start your roscore or a launch file such as helmoro.launch.

A common problem, that occurs is that the machines cannot resolve each others hostname into an IP-address. Check if the IP-address of each machine is visible by typing:

echo $ROS_IP

If there is no IP-address showing up, you can set ROS_IP in each machine environment before starting a node by typing:

export $<Your_IP>

You can also use the following script in each terminal, after you filled in the required values

#!/bin/bash

source /opt/ros/noetic/setup.bash

# select workspace
source /home/$USER/<Your catkin workspace>/devel/setup.bash

# set IP of localhost, ethernet or wifi for using remote roscore
ip_temp=$(hostname -I)
#my_ip = localhost
my_ip=${ip_temp% }

# set IP of roscore
roscore_ip=$my_ip

export ROS_IP=$my_ip
export ROS_HOSTNAME=$my_ip
export ROS_MASTER_URI=http://$roscore_ip:11311

Then, enter the following commands in both terminals:

export ROS_MASTER_URI=http://<IP_of_Master>:11311

Thereby, type in the IP-address of your master-machine instead of .

For further testing, you can use the rostopic tool on all machines that are connected to the master. Using the command rostopic list you should get a list of all available topics. In wireless networks, which our Helmoro uses, it is sometimes necessary to check if there is a connection and messages still come. You can do so by echoing a published topic.

rostopic echo /topic_name

If you are in the HTKZ lab network you can look for Helmoro's IP here

For further reference head to ROS MultipleMachines and ROS NetworkSetup.

Run RViZ with a config file

In order to run RViZ as a standalone directly with the custom config file, type in:

rosrun rviz rviz -d `rospack find helmoro_description`/rviz/rviz_config.rviz

Arguments

You can pass several arguments to the helmoro.launch and other launch files, when running it using:

roslaunch helmoro_description helmoro.launch arg_name:=value

Usage Arguments

The most important arguments for usage are depicted in the following table.

Parameter Default Definition
is_real_robot true Switch to use real robot or gazebo simulation
use_rviz false Switch to use rviz for visualization also activates the joystick
use_joystick = use_rviz Switch to use joystick
use_lidar true Switch to use lidar
use_rgbd_camera true Switch to use rgbd camera

RVIZ Arguments

Parameter Default Definition
rviz_config_file rviz_config.rviz Default rviz config file

Gazebo Arguments

Parameter Default Definition
paused false Switch if gazebo is started running or in paused mode
use_sim_time true Switch if simulated gazebo time or real time is used for simulation
gui false Switch if gui of gazebo is displayed
world helmoro_gazebo_plugin/worlds/helmoro_wohnung_mob Default testing world that is loaded for gazebo simulation

Common commands

To run Helmoro in simulation (in Gazebo) you can call this command on your local computer:

roslaunch helmoro_description showcase_helmoro.launch is_real_robot:=false use_rviz:=true use_gui:=true

You then can add a box into the environment and let Helmoro pick it up. Be reminded that in simulation helmoro does not have a fork (but he can push around objects) and that the odometry is better then in reality.

To run the required nodes for the showcase on Helmoro you can run:

roslaunch helmoro_description showcase_helmoro.launch

Additionally, the above written command to call rviz on your local computer

rosrun rviz rviz -d `rospack find helmoro_description`/rviz/rviz_config.rviz

You then also need to start the joystick node (on your computer) with:

 roslaunch helmoro_joymanager joymanager.launch

Make sure to connect the joystick to your computer

Advanced usage or tuning

If you want to tune the parameters of amcl or the navigation stack, while Helmoro is running you can open the dynamic reconfigure plugin after running:

rosrun rqt_gui rqt_gui