README - RT1 - Assignment 1 - Robot Game

Francesco Ganci - 4143910 - Robotics Engineering - A.A. 2020/2021

Thanks to prof. Carmine Recchiuto for having provded the simulation environment.

Take a look at the video demo of the project!

• video demo Here!

Doxygen Documentation:

• Doxygen Documentation here

How to set up the project

Prerequisites

The only dependency you need in order to run the project is stage_ros, a little 2d simulator for an holonomc robot. You can find more informations online in the official ROS Wiki. However, it is already installed by default in ROS noetic, so you don't have to worry about it.

You don't need anything else in order to run this project.

Compatibility

The project is compatible with both ROS Noetic and ROS Kinetic.

Set-Up

The repository contains only one package, named robot_game. Installing it is simple: go into your preferred workspace (I suggest you to use an empty workspace), folder src, and from there launch the following command:

git clone https://github.com/programmatoroSeduto/RT1_assignment_1.git -b main robot_game

Done this, remember to compile the project: simply launch catkin_make from the root of your workspace. Restart the console, and you're ready.

You could face problems in finding .py nodes; make sure that all the files in the /scripts folder are executable.

How to run the project

This project was implemented in two versions: the first one in C++, and the second one in Python.

Manually run the project

Before launching any of the two available versions, remember to launch the stage_ros simulator. The world file is already in the package.

rosrun stage_ros stageros $(find robot_game)/world/exercise.world &

C++ version:

rosrun robot_game rg_services
rosrun robot_game rg_controller

Python version: sumply add _py.py at the end of the names.

rosrun robot_game rg_services_py.py
rosrun robot_game rg_controller_py.py

Run the project with RosLaunch

Using roslaunch you don't need to start the simulation environment before.

C++ version:

roslaunch robot_game robot_gambe_cpp.launch

Python version:

roslaunch robot_game robot_gambe_py.launch

Structure of the project

Package File System

Here are the significant folders inside this package:

• scripts python scripts
• src c++ code
• include/robot_game contains a configuration file (in python) useful for the python versione of the project
• docs some documentation
• launch the two launch files
• srv contains the definitions of the three services used in this project.
• world contiains only one file .wolrd that is the description of the environment of the robot.

Architecture of the project

Both the versions have the same structure: two nodes,

• the first one provides all the service the controller needs, rg_services
• the secondo one interacts with the simulation for controlling the robot, rg_controller

See this RosGraph:

The node labeled rg_controller reads the actual position from the topic /base_pose_ground_truth, performs some computation generating a twist, and sends it through the topic /cmd_vel.

The other node, rg_services, provides these services to the controller:

• /rg_get_target_srv : generate a random target
• /rg_check_target : check if the robot is located clone enough to the goal position
• /rg_get_vel_srv : generate a linear velocity (as twist9 such that the robot can get closer to the goal

The proposed algorithm works under the assumption that the world is completely free, that is there are no obstacles.