ROS2 Development Skill

When to Use This Skill

• Building ROS2 packages, nodes, or component containers
• Setting up colcon workspaces, ament_cmake, or ament_python packages
• Writing CMakeLists.txt, package.xml, or setup.py for ROS2
• Defining custom messages, services, or actions
• Writing Python launch files with conditional logic
• Configuring DDS middleware and QoS profiles
• Implementing lifecycle (managed) nodes
• Working with Nav2, MoveIt2, or other ROS2 frameworks
• Debugging DDS discovery, QoS mismatches, or build failures
• Deploying ROS2 to production or embedded systems (micro-ROS)
• Setting up CI/CD for ROS2 packages

Core Architecture

1. Node Design Patterns

Basic Node (rclpy):

#!/usr/bin/env python3
import rclpy
from rclpy.node import Node
from rclpy.qos import QoSProfile, ReliabilityPolicy, HistoryPolicy
from std_msgs.msg import String

class PerceptionNode(Node):
    def __init__(self):
        super().__init__('perception_node')

        # 1. Declare parameters with types and descriptions
        self.declare_parameter('rate_hz', 30.0,
            descriptor=ParameterDescriptor(
                description='Processing rate in Hz',
                floating_point_range=[FloatingPointRange(
                    from_value=1.0, to_value=120.0, step=0.0
                )]
            ))
        self.declare_parameter('confidence_threshold', 0.7)
        self.declare_parameter('frame_id', 'camera_link')

        # 2. Read parameters
        rate_hz = self.get_parameter('rate_hz').value
        self.threshold = self.get_parameter('confidence_threshold').value
        self.frame_id = self.get_parameter('frame_id').value

        # 3. Set up QoS profiles
        sensor_qos = QoSProfile(
            reliability=ReliabilityPolicy.BEST_EFFORT,
            history=HistoryPolicy.KEEP_LAST,
            depth=1
        )
        reliable_qos = QoSProfile(
            reliability=ReliabilityPolicy.RELIABLE,
            history=HistoryPolicy.KEEP_LAST,
            depth=10
        )

        # 4. Publishers first, then subscribers
        self.det_pub = self.create_publisher(
            DetectionArray, 'detections', reliable_qos)

        self.image_sub = self.create_subscription(
            Image, 'camera/image_raw', self.image_callback, sensor_qos)

        # 5. Timers for periodic work
        self.timer = self.create_timer(1.0 / rate_hz, self.timer_callback)

        # 6. Parameter change callback
        self.add_on_se
(截断)