ohm_kobuki_sim

This package comprises a pygame-based robot simulation for a kobuki robot.

How to install

Dependencies

Ubuntu 20.04 (recommended)

sudo apt install python3-pip
pip install pygame

Ubuntu 18.04

Tests have been performed with ROS melodic, albeit the used python versions differ. While ROS melodic uses python2.x, the simulator need python3. The reason is, that ROS noetic will require python3. In order to make the simulator work with ROS melodic, you can follow the installation hints below.

Prerequisites on Ubuntu 18.04

Installing python3 aside python2 can be done with pip:

user@machine:~$ sudo apt install python3 python-pip python3-pip python-catkin-tools
user@machine:~$ sudo update-alternatives --install /usr/bin/python python /usr/bin/python2.7 1
user@machine:~$ sudo update-alternatives --install /usr/bin/python python /usr/bin/python3.6 2
user@machine:~$ pip install -U defusedxml rospkg pygame pycryptodomex gnupg pyside2 pydot numpy

Building the package

Go to your catkin workspace and build the package. / execute the following commands (replace the path to your catkin workspace accordingly):

Catkin Make

user@machine:~$ cd ~/catkin_ws
user@machine:~/catkin_ws$ catkin_make
user@machine:~/catkin_ws$ source devel/setup.bash

Catkin Build

user@machine:~$ cd ~/catkin_ws
user@machine:~/catkin_ws$ catkin build ohm_kobuki_sim
user@machine:~/catkin_ws$ source devel/setup.bash

Using the simulator

Start the default launchfile

If you installed all dependencies and built the package without any errors, you should be able to launch the simulator using the following command:

user@machine:~/catkin_ws$ roslaunch ohm_kobuki_sim simulator.launch

Expected output

A window should pop up that displays the environment, the robot and ray-traced laser beams:

Available Topics

Name	In/Out	Type
/kobuki/cmd_vel	In	geometry_msgs/Twist
/kobuki/laser	Out	Sensor_msgs/LaserScan
/kobuki/odom	Out	nav_msgs/Odometry
/kobuki/wheel_speed	Out	ohm_kobuki_sim/WheelSpeed

Controlling the robot and using sensor data

Moving the robot manually

The simulator listens to velocity commands, as published by e.g. the teleop_twist_keyboard tool. To publish them manually, you can use the following command:

rosrun teleop_twist_keyboard teleop_twist_keyboard.py cmd_vel:=/kobuki/cmd_vel

Creating a map

We provide a Gmapping configuration for our simulator to create a map of the environment.

roslaunch ohm_kobuki_sim kobuki_gmapping.launch

This command should open up an RVIZ window with our view that shows the mapping progress:

If you encounter errors, you might need to install gmapping:

sudo apt install ros-noetic-gmapping