Marking criteria submissions will be marked against, are given below. A gradient from Fail, good, very good and excellent will be applied to each.

Aim of this assignment

The aim of this assignment is to give you away into writing software for controlling a (simulated) robot using the Robot Operating System (ROS).

In this assignment you will create a ROS node to drive the robot around with a simple wanderer algorithm, very like a ‘Roomba’ robot vacuum cleaner. The robot should move forward until it reaches an obstacle, then rotate in the same position until the way ahead is clear, then move forward again and repeat. While this can be achieved with a robot that can rotate in one direction, e.g. left only, higher marks will be awarded for submissions that rotate in both directions. The robot in the simulation should be able to move around its environment for a prolonged period (3-5 minutes), without colliding with an object.

Rules and Requirements of your Assignment

Your code must be executable in a Linux environment without any modification. Code submitted which requires modification to run will result in penalty points. For you to work and be able to execute the assignment, make sure you have a ROS2 Distribution (i.e., Foxy) with Gazebo installed. For more information, please have a look at the lecture notes and lab sessions in CANVAS.

Before you start this assignment, you should make sure that you understand basic ROS concepts such as compiling and running a node, both from the command line and through launch files. Finally, make sure that the turtlebot_gazebo packages are installed on your machine, these were presented in Week 4 lecture notes.

The Assignment

1.   Pull code from github into your ROS2 workspace /src folder

$ cd src

$ git clone https://github.com/LJDevlin/Assignment3_ELEC230.git

2.  Your task is now to adapt the code supplied to achieve the task. The code should implement a simple algorithm:

•    If the robot is moving sufficiently close to an obstacle in front of it, then rotate it in the direction that is freer from obstacles (i.e., if there is an obstacle on the robot’s right, it should turn left) until the way ahead is clear;

•    If there is no obstacle blocking its path, move forward as a default.

3.  Verify that your implementation works, by running a launch file (one has been supplied to you in the code in canvas) and watching the robot in the simulator to see that it is operating as intended.

4.  Once you are happy with your code, change the packages.xml file to give a brief description of what the package does.

5.  Write a short document which introduces the assignment, what you did, what worked and what didn’t work, as well as the logic your  robot follows as  it navigates the environment. The full requirements for the report are given below.

The Rules

1.   Make sure that your code is tidy and well-commented. Comments should go beyond what has already been supplied.

2.  This goes without saying: you should do this lab work on your own. All the work you turn in should be yours, and not done in collaboration with anyone else. If you      use      any      external      sources       of      inspiration,      other      than https://docs.ros.org/en/foxy/index.html ,then let us know in a README file.

3.   If you  have  taken  a  VirtualBox  from  a  demonstrator,  then  make  sure  that screenshots  include  a  unique  username.  ELEC230  is  not  a  valid  username. Screenshots should clearly show the time and date.

4.   ROS1 submissions will not be accepted.

5.   Source code must be written in C++.

6.   Page limits must be adhered to, as specified in “What to hand in” below. Penalty points will be applied for going over the limit.

What to Hand In

You should hand in everything that someone else needs to run your code. For this assignment, that means:

•    Your source code. This should be adequately commented, so that each distinct part of the code is clearly explained.

•    manifest file,

•    CMakeLists.txt,

•    launch files.

The structure of the code should be the one that exists in your linux environment. Such that the marker will be able to run your code without moving your files around. For

that reason, please compress the files as they exist in your <ROS_WS>/src

You should also include (alongside your compressed file and not inside it):

•    A Word document including:

o    A cover sheet with title, background, and academic integrity declaration.

o   A discussion of: an introduction; procedures followed; what worked and what did not; the testing carried out; and the logic your robot follows.

This should be 4 pages maximum. Penalty points will be applied if it goes beyond this.

o   The   rest   of  your  Word  document  should   include  screenshots  as described  in  the  Marking  Criteria.  These  should  be  presented  as numbered figures, referred to (where relevant) in your discussion.

You should not hand in executable files e.g from your /install or /build folders, or any other files that can be regenerated.

Your code should be able to run after writing in a terminal:

$ colcon build

Then navigating to your launch file

$ ros2 launch elec230.lauch.py

This is assuming you haven’t changed the name of the launch file we have already supplied to you.