Simulation

Simulation — ROS2 Gazebo & Nav2 Simulation Package

Deployment Target: 🖥️ Gazebo & RViz Simulation

The Simulation package provides the core Gazebo warehouse environment, robot URDF/Xacro definitions (differential drive bot with 2-DOF active camera mast), Nav2 costmap & planner configurations, map assets, and simulation launch files for the WareOps Autonomous Warehouse Robot System.

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📁 Package Architecture & Structure

Simulation/
├── CMakeLists.txt              # Build configuration (ament_cmake)
├── package.xml                 # ROS2 package manifest & dependencies
├── README.md                   # Package documentation
├── config/                     # Navigation, SLAM & Gazebo parameters
│   ├── gazebo_bridge.yaml      # ROS2 ↔ Gazebo Topic Bridge configuration
│   ├── param_nav2.yaml         # Nav2 costmaps, AMCL, planner & controller params
│   └── Slam_param.yaml         # SLAM Toolbox mapping parameters
├── launch/                     # Simulation launch files
│   ├── display.launch.xml              # Launches Gazebo world + robot URDF spawn
│   ├── display_map.launch.xml          # Launches Gazebo world + Nav2 map server
│   └── display_navigation.launch.xml   # Launches full Gazebo + Nav2 AMCL navigation
├── maps/                       # Occupancy grid maps of the warehouse
│   ├── New_map.pgm             # Warehouse layout map grid
│   └── New_map.yaml            # Map metadata (resolution, origin, threshold)
├── rviz/                       # RViz2 visualization display profiles
│   ├── rviz_config.rviz        # Base robot model viewer config
│   └── rviz_config_nav2.rviz   # Nav2 navigation & costmap visualization profile
├── urdf/                       # Robot URDF & Xacro model descriptions
│   ├── base_mobile.xacro       # Chassis, wheels, casters, laser scanner & active vision mast
│   ├── common_properties.xacro # Inertials, colors, material definitions
│   ├── robot_base.urdf.xacro   # Entry URDF loader file
│   └── robot_gazebo.xacro      # Gazebo plugins (diff drive, joint state publisher, camera sensor)
└── world/                      # Gazebo world models & assets
    ├── warehouse.sdf           # Multi-aisle warehouse environment with QR-tagged racks
    ├── multi_camera_viewer.py  # Utility for multi-camera view rendering
    └── materials/              # Custom textures and materials for warehouse racks

Note: System-wide multi-package launch orchestration is centralized in wareops_system_launch.

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⚙️ Core Components

1. Robot Model (URDF / Xacro)

• Chassis: Differential drive mobile platform equipped with dual drive wheels and front/rear passive casters.
• Sensors:
  • 2D LiDAR (/scan) mounted on the robot chassis for SLAM and AMCL localization.
  • Active Vision Camera Mounted on a 2-DOF motorized mast (Yaw rotation + Pitch tilt).
• Joint Position Control Topics:
  • /camera_base_cylinder/cmd_pos (std_msgs/Float64): Rotates camera mast (Yaw: 0.0 to 3.14 rad).
  • /camera_cylinder_sphere/cmd_pos (std_msgs/Float64): Tilts camera lens (Pitch: 0.0 to 1.57 rad).

2. World & Map Environment

• Warehouse World (warehouse.sdf): Includes high-density inventory racks, aisle pathways, walls, and realistic lighting.
• Occupancy Grid (New_map.yaml / New_map.pgm): Calibrated 2D grid map used by Nav2 AMCL localization and costmap cost layers.

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🚀 Launch Configurations

Launch File	Command	Description
Navigation & Map	ros2 launch Simulation display_navigation.launch.xml	Launches Gazebo world, robot spawn, Map Server (New_map.pgm), AMCL localization, Nav2 planners & RViz2.
Map Only	ros2 launch Simulation display_map.launch.xml	Launches Gazebo and Map Server for testing map alignment.
Robot Display	ros2 launch Simulation display.launch.xml	Spawns robot model in Gazebo world without Nav2 navigation stack.

To launch the entire system (Simulation + Nav2 + Teleop + Vision Scanner + Dashboard), use:

ros2 launch wareops_system_launch full_system.launch.py

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📡 Published & Subscribed ROS2 Topics

Topic	Message Type	Direction	Description
/cmd_vel / /diff_cont/cmd_vel_unstamped	geometry_msgs/msg/Twist	Subscribe	Robot movement velocity commands
/scan	sensor_msgs/msg/LaserScan	Publish	2D LiDAR distance scanning data
/camera/image_raw	sensor_msgs/msg/Image	Publish	Simulated RGB camera feed from camera mast
/camera_base_cylinder/cmd_pos	std_msgs/msg/Float64	Subscribe	Gazebo camera Yaw joint position controller
/camera_cylinder_sphere/cmd_pos	std_msgs/msg/Float64	Subscribe	Gazebo camera Pitch joint position controller
/initialpose	geometry_msgs/msg/PoseWithCovarianceStamped	Subscribe	Initial pose estimation for Nav2 AMCL
/amcl_pose	geometry_msgs/msg/PoseWithCovarianceStamped	Publish	Estimated robot position from AMCL filter
/map	nav_msgs/msg/OccupancyGrid	Publish	Static warehouse occupancy grid map

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🛠️ Build & Quick Start Instructions

1. Build Package:

   cd ~/WareOps
   colcon build --packages-select Simulation
   source install/setup.bash

2. Launch Gazebo Simulation with Nav2:

   ros2 launch Simulation display_navigation.launch.xml

3. Launch Complete Multi-Package System:

   ros2 launch wareops_system_launch full_system.launch.py