Selection Task 2021

Hi there, Welcome to the Selection Task(2021).

The TASK provided here is the selection criteria for joining the A.T.O.M society. Those who sucessfully finish the task within the given time frame will be given a chance to give an interview to become a member of the A.T.O.M society.

This task is not just only test your problem solving skills but see your diligence to learn new stuff the ablity to get the work done.

Note

the deadline has been extended New deadline for completing the task: 27th November, 2021

Problem statement

  • The objective of the task is to move the turtle inside the turtlesim window in a circle and stop at its initial location.

  • To acheive this task you are supposed to create a node named /node_turtle_revolve   within a python script,  node_turtle_revolve.py

Note

Dont worry if you are new to ROS or Linux(Ubuntu), the task is fairly simple and we have provided you with ample resource and tutorials in this WIKI to the complete this task so only a strong will and a little bit of brains is required to get the work done. Also even though this just a weekend task we have provided ample amount of time as we also have our midterm exams during this time. So we think a week time is enough so you guys can give your exams freely and manage your time in order to complete the task

Expected Output

Procedure

Follow the instructions given below to get started with the task.

  • First, you will need to create a package named selection_task within your ROS workspace. Once your package is created, source and build your workspace.

  • Within this package, you should have a ‘scripts’ folder inside which you’ll create a python script, named node_turtle_revolve.py.

  • Fill the script with proper programming ethics. Doing this will help us understand your code better and quicker than usual.

  • After completing the python script. Make it executable, if it isn’t already. To do that, enter the following code.

cd ~/catkin_ws
catkin_make
source devel/setup.bash
chmod +x ~/catkin_ws/src/selection_task/scripts/node_turtle_revolve.py

  • Before executing make sure that roscore is running along with turtlesim_node. You can either run them in separate terminals or simply create a selection_task.launch file inside the ~/catkin_ws/src/selection_task/launch/ folder. Launch file can run multiple nodes unlike a python/cpp script. Run the launch file, enter, This should run three processes in parallel.

  • roscore

  • turtlesim_node

  • node_turtle_revolve.py

See also

Please refer to the tutorials and resouces given in the wiki or visit the official ROSWIKI if you need help with anything regarding ROS.

Hints

  • The turtle needs to move in a circular motion with a certain radius. This radius should be sufficient to fit within the turtlesim window. But making it rotate in a circular manner, with only velocities to control is something to think about.

  • Use linear velocity as well as angular velocity with some combination to get this done.

  • Keep tracking the distance travelled so as to know when to stop. You can refer to Overview of rospy for more hint

Submissions

For Submissions of your work please refer to the following instructions

  • Video

    • After completing the task, record a video of your work as shown in the expected output in the problem statement page

    • Once the video is recorded, upload the video to Youtube as an unlisted video

  • Code

    • Once your script is complete, add comments to your code to make it more readable.

    • Create a copy of your script and rename it as task_.py . Your example if your name is ‘Alex’, then rename your script as task_alex.py

  • Submissions

    • Once your have both of the above things ready, submit the YouTube link of the video and the script in the google form given below

  • Interview

    • Once we review your submission, we will be calling you for a personal interview based on your work.

Google Form for Task submission

Note

Even if you are not able to complete entire the task you are requested to make the submission of the work that you have done anyway.