.. _architecture:

Tutorial for Running Robile in Simulation 
=========================================

In this tutorial, we will learn how to launch and control Robile in simulation. 
If you have not followed through _getting_started, please do so before continuing.

**Launching Robile**

  Before launching Robile, make sure that you have sourced the *setup.bash* file in your workspace. 
  This is a one time activity per terminal.

  .. code-block:: bash

      source ~/ros2_ws/install/setup.bash

  .. note::
    Please deactivate `conda` environment if it is activated. The `conda` environment can be deactivated 
    by running **conda deactivate** command in the terminal. To do this globally, run **conda config --set auto_activate_base false** 
    command in the terminal. This will deactivate the `conda` environment by default.

  Now we will run the launch file to launch Robile in simulation. You will see a Gazebo window pop up with Robile in it and an **rviz** window. 
  For the first time, it might take a while to load the Gazebo environment. Click on the *file* tab in the rviz window and select *open config*. 
  Choose the file **robile.rviz** from the *rviz* folder in the **robile_gazebo/config/** folder.

  .. code-block:: bash

      ros2 launch robile_gazebo gazebo_4_wheel.launch.py  

  .. note::  


    1. If the platform is not spawned, please stop the simulation by `Ctrl+C` and launch the simulation again. 
    (Please do not use `Ctrl+Z` to stop the simulation. It will not kill the script but will continue running it in the background)  

    2. If the launch file stops by itself or even after pressing `Ctrl+C`, please verify if any process named `gzclient` is running. If it exists, then kill the process by using the PID associated with the process by using ``kill -9 <PID>`` command. In this command, replace the `<PID>` with the PID of the process. The PID can be found by running ``ps`` command in the terminal.  


    3. If you see an error stating ``[gzclient-3] gzclient: ....  Assertion px != 0 failed.`` in the terminal, add the following line to your **.bashrc** file: ``source /usr/share/gazebo/setup.sh``. If you are using the same terminal then source the .bashrc file. 

  Great job! You have successfully launched the simulation.
  If you are facing any issues, please feel free to post any of your queries in the AMR forum (lea).     

**Controlling Robile** 

  The robot can be controlled using the keyboard or by publishing to the */cmd_vel* topic.
  To control the robot using the keyboard, run the following command in a new terminal. Make sure that you have sourced the *setup.bash*  file in new terminal as well.
  You can use the keys *i*, *j*, *k*, *l*, *u*, *o*, *m*, and *,* to control the robot.

  .. code-block:: bash

      ros2 run teleop_twist_keyboard teleop_twist_keyboard

  To control the robot by publishing to the */cmd_vel* topic, run the following command in a new terminal. Make sure that you have sourced the *setup.bash*  file in new terminal as well.
  For example, to move the robot forward at a linear velocity of 0.5 m/s, run the following command.

  .. code-block:: bash

      ros2 topic pub /cmd_vel geometry_msgs/Twist '{linear: {x: 0.5, y: 0.0, z: 0.0}, angular: {x: 0.0,y: 0.0,z: 0.0}}'