🔗 System Integration

How does all your code, hardware, and ROS2 nodes actually work together?
This page shows how your custom logic, third-party packages, and real hardware connect in a single ROS2 ecosystem.

---

🧩 How Your Code Fits into ROS2

Your project is a classic ROS2 modular system:

• Each function (detection, navigation, manipulation, state management) is a separate node.
• Nodes interact via topics, services, and actions.
• The mission manager node acts as the “brain,” coordinating everything and handling real-time events.

Tip

“Think of every major box in your system as a separate node. Each node is replaceable, debuggable, and testable on its own.”

---

🗺️ System Integration Diagram

---

🔄 Communication Patterns

Pattern	Example in Your Project
Topic	/target_pose from Detector → Mission Manager
Action	Navigation goals via nav2_msgs/action/NavigateToPose
Service	(Optional) Reset, trigger, parameter tuning
Parameter	Launch configs, runtime tuning (e.g., thresholds, IP addresses)
TF Frames	Camera, base_link, map, arm, all dynamically linked

Typical Flow:

1. Robot explores via Navigation Node
2. Object Detector publishes /target_pose on detection
3. Mission Manager interrupts navigation, coordinates approach, triggers pick/drop nodes
4. Pick/Drop Node interacts with MyCobot, Mission resumes or returns
5. All state and pose info flows through topics or actions

---

⚡️ System Coordination Example

Normal Operation

1. Launch all nodes with full_system.launch.py
2. Robot starts exploring waypoints
3. Object is detected: /target_pose published
4. Mission Manager:
   • Pauses exploration
   • Sends goal to Navigation Node
   • On arrival: triggers Pick Node
   • Waits for success/failure
   • Sends “return to base” goal
   • Triggers Drop Node
   • Resumes or finishes

Interrupt & Error Handling

• If Pick fails: Mission Manager reports error, may retry or abort
• If object detection is unstable: resumes exploration, waits for new target
• All errors logged, state managed in Mission Manager Node

---

🕸️ How Each Node Communicates

Node	Publishes	Subscribes to	Actions/Services
Object Detector	/target_pose	Camera, Depth topics	—
Mission Manager	Navigation goal, /cmd_vel	/target_pose, feedback	Triggers pick/drop
Navigation Node	Robot movement	Goal poses	NavigateToPose action
Pick/Drop Node	Arm/gripper commands	Trigger from Mission	—
Pose Setter	Initial pose to Nav Node	Manual or launch	—

---

👨‍💻 System Integration Best Practices

• Use launch files to manage startup dependencies and correct launch order (see full_system.launch.py)
• Keep all custom code in your external workspace
• Use actions for long-running tasks (navigation, arm movement), topics for rapid data/events
• Always test each node individually before full system bring-up
• Use RQT Graph and RViz to debug connections and visualize state

---

🚦 Next Steps

• System Usage: Running Everything
• Advanced Integration & Customization
• Troubleshooting

---