The instructions to build the drivers and ROS nodes for youbot for ROS melodic

netplan example yaml file

# This file describes the network interfaces available on your system
# For more information, see netplan(5).
# Mind the indentation !
network:
  version: 2
  renderer: networkd
  ethernets:
    enp0s25:
      dhcp4: yes
    ens36:
      dhcp4: yes
  wifis:
    wlx08863ba6ef81:
      dhcp4: yes
      access-points:
        "NomDuReseau":
          password: "passphrase"

Ubuntu 18.04 Youbot installation

# Ubuntu 18.04 installation

Proceed with a minimal installation of ubuntu 18.04, follow https://help.ubuntu.com/community/Installation/MinimalCD

# ROS installation

Follow http://wiki.ros.org/melodic/Installation

# Network configuration in console mode

You must modify the file /etc/netplan/01-netcfg.yaml   
An example file is given below

For filling in this file, you need the names of your interfaces

  $ apt install net-tools
  $ ifconfg -a 

Once done with the config file :

  $netplan apply

# Configuring the dynamic linker


  $ cd /etc/ld.so.conf.d/
  $ nano ros.conf

Then add :

  /opt/ros/melodic/lib/

And call

$ ldconfig

# ROS drivers installation 

  $ mkdir catkin_ws
  $ cd catkin_ws
  $ catkin_init_workspace
  $ cd <catkin_ws>/src

  $ git clone https://github.com/youbot/youbot_driver.git
  $ cd youbot_driver
  $ git checkout hydro-devel
  $ cd ..

  $ git clone https://github.com/youbot/youbot_driver_ros_interface.git
  $ git clone https://github.com/youbot/youbot_description.git
  $ cd youbot_description
  $ git checkout kinetic-devel
  $ cd ..
  $ git clone https://github.com/youbot/youbot_navigation.git

// Fixing youbot_navigation_common
Modify youbot_navigation/youbot_navigation_common/CMakeLists.txt and add the following just before the target_link_libraries
include_directories(${catkin_INCLUDE_DIRS})  

  # Install some dependencies
  $ sudo apt install ros-melodic-brics-actuator ros-melodic-pr2-msgs

  $ cd <catkin_ws>/src
  $ catkin build

# Changing the ethercat config

Modify in catkin_ws/src/youbot_driver/config/youbot-ethercat.cfg 
by changing the ethercat name with yours (in our case, that was ens36 instead of eth0)

==> At that point, you should be able to run 

  $ roslaunch youbot_driver_ros_interface youbot_driver.launch youBotHasArms:=false
  
and to rostopic pub a twist on the /cmd_vel topic; your robot should be moving. 
We did not try yet to use the arms.

# Setting up the Hokuyp

  $ apt install ros-melodic-urg-node -y
  // Gives the permission to your user to access the device
  $ sudo adduser $USER dialout
  // Define a specific udev rule to get a constant named /dev symlink for the hokuy
  $ sudo cp 47-hokuyo.rules /etc/udev/rules.d
  // apply the new rules
  $ sudo service udev reload
  $ sudo service udev restart
  // **Unplug and plug** your Hokuyo
  // The following should show you the symlink
  $ ls -all /dev/sensors/hokuyo