ROS 2 + Gazebo Robot Simulation

A 6-wheeled Mars rover simulation with IMU and camera sensors, built with ROS 2 Humble and Gazebo Ignition (Harmonic). Features ArUco marker detection for visual perception and localization.

Features

• 6-Wheeled Mars Rover: Differential drive with suspension arms, modular URDF/Xacro design
• Sensors: IMU (100 Hz) and RGB camera (640×480 @ 30 Hz) with realistic noise modeling
• Custom World: 4 ArUco marker poles (IDs 51-54) positioned in 6m × 6m square
• Teleoperation: Python GUI with sliders for manual control
• ROS 2 Integration: Complete topic bridging, TF tree management, and sensor data publishing

Prerequisites

• Ubuntu 22.04 LTS
• ROS 2 Humble
• Gazebo Ignition (Sim 8.11.0+)
• Python 3.10+

Quick Start

1. Verify Installation

cd ~/Desktop/ROARTASK
./verify_installation.sh
./verify_marker_world.sh

2. Build Workspace

cd ros2_ws
source /opt/ros/humble/setup.bash
colcon build
source install/setup.bash

3. Launch Simulation

# Using alias (recommended)
rosgp

# Or full command
ros2 launch my_robot_gazebo spawn_robot.launch.py

4. Control Robot (Optional)

# Terminal 2: Launch teleop GUI
python3 robot_teleop_gui.py

5. View Camera Feed (Optional)

# Terminal 3: View camera
ros2 run rqt_image_view rqt_image_view
# Select topic: /camera/image_raw

Available Aliases

Add to ~/.bashrc for convenience:

alias rosb='cd ~/Desktop/ROARTASK/ros2_ws && source /opt/ros/humble/setup.bash && colcon build --symlink-install && source install/setup.bash'
alias rosd='cd ~/Desktop/ROARTASK/ros2_ws && source install/setup.bash && ros2 launch my_robot_description display.launch.py'
alias rosg='cd ~/Desktop/ROARTASK/ros2_ws && source install/setup.bash && ros2 launch my_robot_description gazebo.launch.py'
alias rosgp='cd ~/Desktop/ROARTASK/ros2_ws && source install/setup.bash && ros2 launch my_robot_gazebo spawn_robot.launch.py'
alias rosgu='cd ~/Desktop/ROARTASK/ros2_ws && source install/setup.bash && python3 robot_teleop_gui.py'

• rosb - Build workspace
• rosd - Launch RViz (visualization only)
• rosg - Launch Gazebo (empty world)
• rosgp - Launch Gazebo (marker world) ⭐ Recommended
• rosgu - Launch teleop GUI

Project Structure

ROARTASK/
├── ros2_ws/
│   └── src/
│       ├── my_robot_description/    # Robot URDF/Xacro models
│       ├── my_robot_gazebo/         # Simulation worlds & models
│       │   ├── worlds/              # marker_world.world
│       │   ├── models/              # pole51-54 (local)
│       │   └── launch/              # spawn_robot.launch.py
│       ├── my_robot_perception/     # Perception integration
│       └── aruco_tracking/          # ArUco detection node
├── verify_installation.sh           # Environment check
├── verify_marker_world.sh           # Marker world check
├── CAMERA_TESTING_GUIDE.md          # Camera testing
├── MARKER_WORLD_GUIDE.md            # World creation guide
└── README.md                        # This file

System Architecture

Coordinate Frames:

• base_footprint → base_link → imu_link, camera_link, 6 arms, 6 wheels

Data Flow:

Gazebo Sensors → ros_gz_bridge → ROS 2 Topics
  ├─ IMU      → /imu/data (100 Hz)
  ├─ Camera   → /camera/image_raw (30 Hz)
  │           → /camera/camera_info
  ├─ Odometry → /odom (50 Hz)
  └─ Control  ← /cmd_vel (teleop input)

Common Commands

# Topics
ros2 topic list
ros2 topic hz /camera/image_raw
ros2 topic echo /imu/data

# TF Tree
ros2 run tf2_tools view_frames

# Nodes
ros2 node list
ros2 node info /robot_state_publisher

# Gazebo
gz topic -l
gz model -l

Troubleshooting

Robot Not Spawning

Solution: Wait 3 seconds for Gazebo to load (automatic delay in launch file)

Camera Feed Not Showing

Solution: Check bridge is running:

ros2 node list | grep bridge
ros2 topic list | grep camera

Teleop Not Working

Solution: Verify cmd_vel bridge:

ros2 topic info /cmd_vel
# Should show publishers and subscribers

Markers Not Visible

Solution: Verify models are in workspace:

ls ros2_ws/src/my_robot_gazebo/models/
# Should show: pole51 pole52 pole53 pole54

Documentation

• CAMERA_TESTING_GUIDE.md: Camera sensor testing procedures
• MARKER_WORLD_GUIDE.md: Step-by-step world creation guide
• tasks.md: Implementation task list
• requirements.md: System requirements
• design.md: Architecture design

Development Status

Phase 4 Complete - Environment and Perception

✅ Completed:

• Environment setup (ROS 2 Humble + Gazebo Sim 8.11.0)
• 6-wheeled Mars rover model with suspension
• IMU sensor integration with noise modeling
• Camera sensor integration (640×480 @ 30 Hz)
• Custom marker world with 4 ArUco poles
• Differential drive control system
• Teleoperation GUI
• ArUco marker detection integration
• Complete system visualization in RViz

Resources

• ROS 2 Humble Documentation
• Gazebo Ignition Documentation
• ROS 2 + Gazebo Integration

License

Educational project for ASU ROAR'26 Solo Mission Part 2 assignment.

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Version: 1.0.0 | Last Updated: April 29, 2026 | Status: All Tasks Complete