Turtlebot operation in Gazebo

Here will be scripts, sources and other files for performing vSLAM on Turtlebot in Gazebo environments. Now here is script turtlebot_mover.py which contains code for moving Turtlebot in simulated environments by direct setting its coordinates.

Requirements

• Linux-based system with ROS installed
• ROS package turtlebot3_gazebo (can be found at https://wiki.ros.org/turtlebot3_gazebo)
• Python 2.7 or higher

Turtlebot Mover Description

Turtlebot movement is performed with TurtlebotMover class of script turtlebot_mover.py.

This class has the following params:

• name - name of Turtlebot model in Gazebo. Default is turtlebot3
• max_angular_speed - maximum speed of Turtlebot's rotation (in rad/s). Without constraints, Turtlebot will be rotate with such angular speed. Default is 0.5
• max_linear_speed - maximum speed of Turtlebot's movement (in m/s). In case of moving by line, or by circle with enough big radius, Turtlebot moves with this linear speed. Default is 0.5
• trajectory_type - type of Turtlebot's trajectory. If this parameter is set as line, Turtlebot rotates until it is directed to destination, then moves directly, along line. If this parameter is set as circle, Turtlebot moves along arc of circle until it is directed to destination, then moves directly, along line. Default is line

Movement is performed with move_to method of the class. This method takes two float numbers - coordinates of the destination.

Running Turtlebot Mover

To move Turtlebot in Gazebo environments, make the following steps:

1. Start ROS core

2. In other terminal, choose Turtlebot model as waffle_pi:

export TURTLEBOT3_MODEL=waffle_pi

3. Launch Gazebo with Turtlebot in some environment, for example, turtlebot3_house:

roslaunch turtlebot3_gazebo turtlebot3_house.launch

4. In one more terminal, start Python and move Turtlebot using TurtlebotMover class:

from turtlebot_mover import TurtlebotMover
mover = TurtlebotMover(max_angular_speed=0.5, max_linear_speed=0.5, trajectory_type='line')
x = 0
y = 0
mover.move_to(x, y)

If you have many Pythons (for example, system Python and Anaconda Python), you may face with some Python errors. To fix these errors, set your PATH system variable to satisfy ROS's python (for example, remove Anaconda from PATH if your ROS is with system Python)