Task 5

Droid Arm Trials in the Holochamber

Points for this task: 150

The Droid Arm Trials – Simulation in the Holochamber

A rogue droid arm has been discovered in the ruins of a Jedi Temple. Your mission, young apprentice, is to restore its function using the sacred tools of ROS 2 and simulate it in the holorealm of Ignition Gazebo. The task demands dexterity in code, clarity in control, and honor in motion.

Holotask Briefing

You are entrusted with the remains of a 3-DOF manipulator, and must bring it to life in simulation.

Your objectives:

  1. Summon the robot inside Ignition Gazebo using the Force of URDF and STL meshes.
  2. Control its every move by interpreting the scroll of joint angles.
  3. Organize your code like a true Knight of ROS — modular and sacred to best practices.

Provided Files

All resources for this mission are stored in this datavault:
👉 GitHub Repository – Click Here

The repository contains:

  • meshes/: STL files for robot visualization and collision modeling.
  • ros_task/: Supporting files like DH parameters and joint angle commands.
  • config/: Control configurations for ros2_control.
  • launch/: Launch files for the simulation and robot spawn.
  • src/: Skeleton of the Python node for publishing joint commands.
  • CMakeLists.txt and package.xml: Build and installation setup (some parts incomplete – complete them!).

Use these files as your only source. Do not forge components from the void.

Your Trials

I. Implement src/fk_task.py

You must become one with the node. This ROS 2 Python node should:

  • Parse the joint angles and gripper commands from angles.txt.
  • Publish joint positions to the topic /forward_position_controller/commands every 2 seconds.
  • Compute and print the end-effector position using DH parameters.
  • (Optional) Log the final end-effector position to a file for Jedi Archives.

II. Complete launch/display.launch.py

This file is your portal to the holorealm. You must:

  • Set up the simulation environment for Ignition Gazebo.
  • Launch Ignition Gazebo with a clean world.
  • Include the spawn_robot.launch.py to manifest the droid arm.
  • Ensure all control systems come online.

III. Do Not Modify spawn_robot.launch.py

This file has already been forged by the High Council of Robotics. Study it if you must, but do not alter its form.

Final Submission Checklist

  • You have written fk_task.py to read joint angles and send them to the robot.
  • You have completed display.launch.py so it opens Ignition Gazebo and loads the robot.
  • The robot moves correctly in the simulation based on the angle values.
  • You recorded a video showing your terminal and the simulation working together.
  • You saved the final position of the robot arm’s end (end-effector) in a .txt file.

Use Not the GPT Droids

“These are not the droids you’re looking for…”
This mission tests your command over the code. Do not call upon the AI — only your own strength in the Force.

May your joints never lag, and your transforms never fail. https://forms.gle/Fuk7ZZD2bVGyFjRX9

Submit Here