ROS 2 Humble Installation Guide

NVIDIA Driver Issues (RTX 50-series)

• If screen freezes: Press Ctrl+Alt+F3 to switch to TTY
• Consider Ubuntu 24.04 + ROS2 Jazzy for newer GPUs
• Recovery: sudo apt-get install --reinstall nvidia-driver-535

Apple Silicon (M1/M2/M3/M4)

• Use UTM with Ubuntu 22.04 ARM64
• Expect software rendering (no GPU acceleration)
• Docker ARM64 images available as alternative

Virtual Machine Performance

• Allocate minimum 8GB RAM, 6 CPU cores
• Enable virtualization in BIOS/UEFI
• Add to ~/.bashrc: export LIBGL_ALWAYS_SOFTWARE=true

ROS2 Control is a framework for robots that acts as a middleman between robot hardware and software. It's essential for controlling the Husky+UR3 mobile manipulator in Assignment 4.

Key Components:

• Controller Manager: Manages multiple controllers (loads, unloads, coordinates execution)
• Resource Manager: Manages hardware interfaces and communication with actual hardware
• Hardware Interfaces:
  • Command Interfaces: Write to hardware (position, velocity, effort commands)
  • State Interfaces: Read from hardware (current position, velocity, effort)

Common Controllers for Assignment 4:

• Joint Trajectory Controller: For arm movements (takes trajectory goals)
• Diff Drive Controller: For mobile base (takes cmd_vel commands)
• Gripper Action Controller: For gripper control
• Joint State Broadcaster: Publishes joint states to /joint_states topic

Install ROS2 Control Packages:

sudo apt-get install ros-${ROS_DISTRO}-ros2-control \
                     ros-${ROS_DISTRO}-ros2-controllers \
                     ros-${ROS_DISTRO}-gripper-controllers \
                     ros-${ROS_DISTRO}-gazebo-ros2-control

Essential Controller Commands:

# List active controllers
ros2 control list_controllers

# List hardware interfaces
ros2 control list_hardware_interfaces

# Load and activate a controller
ros2 control load_controller --set-state active arm_controller

# Move the arm (example)
ros2 topic pub --once /arm_controller/joint_trajectory \
  trajectory_msgs/msg/JointTrajectory \
  "{joint_names: ['shoulder_pan_joint', 'shoulder_lift_joint', ...],
    points: [{positions: [0.0, -1.57, 0.0, ...],
    time_from_start: {sec: 3}}]}"

Gripper Control (Robotiq):

# Open gripper
ros2 topic pub /gripper_controller/command std_msgs/msg/Float64 "{data: 0.0}" --once

# Close gripper
ros2 topic pub /gripper_controller/command std_msgs/msg/Float64 "{data: 0.7}" --once

Create a controllers.yaml file to configure your controllers:

controller_manager:
  ros__parameters:
    update_rate: 10

    arm_controller:
      type: joint_trajectory_controller/JointTrajectoryController

    base_controller:
      type: diff_drive_controller/DiffDriveController
      command_interface: "velocity"  # CRITICAL LINE often missing!

    joint_state_broadcaster:
      type: joint_state_broadcaster/JointStateBroadcaster

arm_controller:
  ros__parameters:
    joints:
      - shoulder_pan_joint
      - shoulder_lift_joint
      - elbow_joint
      - wrist_1_joint
      - wrist_2_joint
      - wrist_3_joint
    command_interfaces:
      - position
    state_interfaces:
      - position

• Realistic Mars terrain with NASA/JPL resources
• Custom Mars world for Husky+UR3 navigation
• SLAM challenges with Martian obstacles
• Optional: Fun race track on Mars surface!
• Inspired by MASt3R-SLAM (CVPR 2025)

Setup Guide:

Complete Mars world setup instructions available: View Mars Tutorial

Part 2 Requirements:

• Sensor Fusion (15 pts): EKF implementation
• Path Planning & Control (15 pts): Navigate Mars terrain
• SLAM Implementation (10 pts): 2D mapping with laser scanner
• Mars Bonus (+10 pts): Complete tasks in Mars environment
• Documentation (10 pts): RSS format technical report

• Mobile Robotics Textbooks - Essential PDFs for the course
• Office Hours: In-person at SC 4407 (check Campuswire for Zoom sessions)
• Gradescope: Course ID: 1102297, Entry Code: KDP5G8
• GitHub TA Username: kulbir-ahluwalia (add to private repos)

Quick reference for common Git operations used throughout the course:

• Repository Setup: Clone, fork, and initialize repositories
• Version Control: Add, commit, push, and pull changes
• Branching: Create and merge branches for feature development
• Collaboration: Pull requests and code reviews
• Troubleshooting: Common Git issues and solutions

Initial Setup (Do Once)

# Configure your identity
git config --global user.name "Your Name"
git config --global user.email "your.email@illinois.edu"

# Clone course repository
git clone https://github.com/yourusername/CS498GC_assignments.git
cd CS498GC_assignments

Daily Workflow

# Check status
git status

# Stage your changes
git add coding_ex1_part1.py coding_ex1_part2.py

# Commit with descriptive message
git commit -m "feat: Implement wheel odometry with gyro fusion"

# Push to GitHub
git push origin main

For Gradescope Submissions

# Create submission branch
git checkout -b assignment4-submission

# Tag your final version
git tag -a v1.0 -m "Assignment 4 Final Submission"
git push origin v1.0

# Add TA as collaborator
# Add username: kulbir-ahluwalia to your private repository

Use this .gitignore for your ROS2 workspace:

# ROS2 build artifacts
build/
install/
log/

# Python
__pycache__/
*.pyc
*.pyo
*.egg-info/

# Results
*.txt
*.csv
*.db3

# IDE
.vscode/
.idea/
*.swp

# OS
.DS_Store
Thumbs.db

Before asking for help, verify:

• ☐ Bag file playing (see topic messages)
• ☐ Input topics showing Hz values (~10 Hz for gyro)
• ☐ /odom topic publishing at ~10 Hz
• ☐ Node running without Python errors
• ☐ RViz2 Fixed Frame set to 'odom' (not 'map')
• ☐ Path display added with buffer 10000
• ☐ Output file showing changing x,y values
• ☐ No math.radians() on gyro data
• ☐ Theta updated BEFORE position
• ☐ GPS replaces (not adds to) position