Configure ROS melody for Ubuntu 18.04.05 LTS and solve various problems in detail (pit filling)

Posted by meir4u on Sun, 30 Jan 2022 08:57:45 +0100


ROS includes multiple versions, which are suitable for different versions of Linux systems. ( View the corresponding relationship of each version)
This paper mainly aims at:
Operating system: Ubuntu 18.04.05 LTS
ROS version: Melody

The installation process mainly refers to: ROS official tutorial

Introduction to installation process

The official course of ROS is briefly introduced as follows:

1) Open "software & update" and select "restricted," "universal," and "diverse.", Detailed description is available( link).

2) Set download source

sudo sh -c 'echo "deb $(lsb_release -sc) main" > /etc/apt/sources.list.d/ros-latest.list'

In order to avoid the subsequent error of unable to locate the software package, Deb can be used Replace with deb

3) Set secret key

sudo apt-key adv --keyserver 'hkp://' --recv-key C1CF6E31E6BADE8868B172B4F42ED6FBAB17C654

If an error occurs, you can try to replace the "" part of the above command with
hkp:// Or hkp://

Alternatively, you can use the following command:

curl -sSL '' | sudo apt-key add 

4) Install ROS


sudo apt update

Then use

sudo apt install ros-melodic-desktop-full

The above command is to install the complete ROS. If you want to make a choice, you can also refer to the following command: (if you don't choose to install the full version directly, you can ignore the following contents)

Desktop Install: ROS, rqt, rviz, and robot-generic libraries

sudo apt install ros-melodic-desktop

ROS-Base: (Bare Bones) ROS package, build, and communication libraries. No GUI tools.

sudo apt install ros-melodic-ros-base

Individual Package: You can also install a specific ROS package (replace underscores with dashes of the package name):

sudo apt install ros-melodic-PACKAGE


sudo apt install ros-melodic-slam-gmapping

To find available packages, use:

apt search ros-melodic

5) Environment settings (add ros environment variable)

echo "source /opt/ros/melodic/setup.bash" >> ~/.bashrc
source ~/.bashrc

6) Build package dependencies
Install tools to establish ROS:

sudo apt install python-rosdep python-rosinstall python-rosinstall-generator python-wstool build-essential

7) Initialize rosdep

Install a rosdep first

sudo apt install python-rosdep

Then initialize:

sudo rosdep init

The following errors may occur in this step:
ERROR: cannot download default sources list from:
Website may be down.
This is because domestic access to foreign networks is relatively slow.
**Solution (1) * * is:

#Open the hosts file
sudo gedit /etc/hosts
#Add at the end of the file
#Exit after saving and try again. You can try several more times

The following interface indicates success:

If not, use * * solution (2) * * as: 20 default List file, mainly the web address
The replacement file can be downloaded here and then replaced with the command:

sudo cp ./20-default.list /etc/ros/rosdep/sources.list.d

#Note that the above command is: sudo cp native path / 20 default list /etc/ros/rosdep/sources. list. d

Or open 20 default List file for editing

sudo gedit /etc/ros/rosdep/sources.list.d/20-default.list

Amend the whole content to the following:

# os-specific listings first
# yaml osx
yaml file:/etc/ros/rosdep/sources.list.d/rosdistro-master/rosdep/osx-homebrew.yaml osx

# generic
# yaml
# yaml
# yaml
# gbpdistro fuerte

yaml file:/etc/ros/rosdep/sources.list.d/rosdistro-master/rosdep/base.yaml
yaml file:/etc/ros/rosdep/sources.list.d/rosdistro-master/rosdep/python.yaml
yaml file:/etc/ros/rosdep/sources.list.d/rosdistro-master/rosdep/ruby.yaml
gbpdistro file:/etc/ros/rosdep/sources.list.d/rosdistro-master/releases/fuerte.yaml fuerte

# newer distributions (Groovy, Hydro, ...) must not be listed anymore, they are being fetched from the rosdistro index.yaml instead

After modification, use the rosdep update command to update. If there is a time out error, it is still because the speed of accessing the Internet is too slow or unable to access.
Solution (1): increase the time allowed to try and modify / usr / lib / python2 Three files under 7 / dist packages / rosdep2 /_ list. py,,
Download in_ Timeout = 15.0 value. Open the corresponding file:

sudo gedit /usr/lib/python2.7/dist-packages/rosdep2/
sudo gedit /usr/lib/python2.7/dist-packages/rosdep2/
sudo gedit /usr/lib/python2.7/dist-packages/rosdep2/

Modify Download_ The value of timeout = 15.0 is DOWNLOAD_TIMEOUT = 1500.0
Then try many times to see if it can succeed. If not, try the solution (2).

Solution (2): download the file rosdistro master locally by offline download, and then modify / usr / lib / python2 7 / dist packages / rosdep2 /_ list. py,,rep3. The location in py points to the local location.
(Download method 1 github , download method 2 (CSDN)

Unzip the downloaded file and move it to the corresponding location:

sudo cp -r ./rosdistro-master/ /etc/ros/rosdep/sources.list.d

#Note that the above command is: sudo cp -r local path / rosdistro master / / etc / ROS / rosdep / sources list. d

Then modify / usr / lib / python2 7 / dist packages / rosdep2 /_ list. py,,rep3. Location pointed in py:

First file:

sudo gedit /usr/lib/python2.7/dist-packages/rosdep2/
# Modify DEFAULT_SOURCES_LIST_URL is offline path
DEFAULT_SOURCES_LIST_URL = 'file:/etc/ros/rosdep/sources.list.d/20-default.list'

Second file:

sudo gedit /usr/lib/python2.7/dist-packages/rosdep2/
# Modify REP3_TARGETS_URL is offline path
REP3_TARGETS_URL = 'file:/etc/ros/rosdep/sources.list.d/rosdistro-master/releases/targets.yaml'

Third file:

sudo gedit /usr/lib/python2.7/dist-packages/rosdistro/
# Modify DEFAULT_INDEX_URL is offline path
DEFAULT_INDEX_URL = 'file:/etc/ros/rosdep/sources.list.d/rosdistro-master/index-v4.yaml'

Finally, use the rosdep update command, and the following interface appears, indicating success:

Note: when the above rosdep init and rosdep update have errors, the upper and lower solutions (1) are corresponding (or try to access the Internet), and the solution (2) is also corresponding (download the file locally and modify the link to)

Case use

After completing the above steps, we have completed the whole process of ros installation, and then conduct a case test:
Commands used in the terminal:


Press Ctrl+Shift+T to open a new terminal and use the command:

rosrun turtlesim turtlesim_node

A static Little Turtle interface appears:

Ctrl+Shift+T shortcut key to open a new terminal again, and use the command: enable the keyboard control node that starts turnlesim_ teleop_ key

rosrun turtlesim turtle_teleop_key

Put the mouse on the third terminal interface and control the movement of the little turtle up, down, left and right on the keyboard. The track is as follows.

OK, so far, the installation process of ROS is completed.

Topics: Ubuntu ROS